BTB (Broad-Complex, Tramtrack and Bric a brac)/POZ (poxvirus and zinc finger) domain found in potassium channel tetramerization domain-containing protein 3 (KCTD3) and SH3KBP1-binding protein 1 (SHKBP1); The group of KCTD proteins includes KCTD3 and SHKBP1. KCTD3, also called renal carcinoma antigen NY-REN-45, is a BTB/POZ domain-containing protein that is an accessory subunit of potassium/sodium hyperpolarization-activated cyclic nucleotide-gated channel 3 (HCN3), upregulating its cell-surface expression and current density without affecting its voltage dependence and kinetics. SHKBP1, also called SETA-binding protein 1, interacts with cathepsin B and participates in tumor necrosis factor (TNF)-induced apoptosis in ovarian cancer cells. It can promote epidermal growth factor receptor (EGFR) signaling by interrupting c-Cbl-CIN85 complex and inhibiting EGFR degradation. The BTB/POZ domain, also known as tetramerization (T1) domain, is a versatile protein-protein interaction motif that facilitates homodimerization or heterodimerization. KCTD family BTB domains can adopt a wide range of oligomerization geometries, including homodimerization, tetramerization, and pentamerization.

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1834198877  10 SDLVNLNVGGQRFSTSRQTLTWIPDTFFTALLSGRISSLRDEHNAIFIDRDPTLFSIILNYLRTKDIDIKNCEIRALRHE 89
Cdd:cd18363     1 GDIINLNVGGKRFSTSRQTLTWIPDSFFTSLLSGRISSLKDETGAIFIDRDPKLFSIILNYLRTKEIDLRNVDISSLRHE 80

                  ....*.
gi 1834198877  90 AEYYGI 95
Cdd:cd18363    81 AEFYGI 86

BTB (Broad-Complex, Tramtrack and Bric a brac)/POZ (poxvirus and zinc finger) domain found in potassium channel tetramerization domain-containing protein 3 (KCTD3) and SH3KBP1-binding protein 1 (SHKBP1); The group of KCTD proteins includes KCTD3 and SHKBP1. KCTD3, also called renal carcinoma antigen NY-REN-45, is a BTB/POZ domain-containing protein that is an accessory subunit of potassium/sodium hyperpolarization-activated cyclic nucleotide-gated channel 3 (HCN3), upregulating its cell-surface expression and current density without affecting its voltage dependence and kinetics. SHKBP1, also called SETA-binding protein 1, interacts with cathepsin B and participates in tumor necrosis factor (TNF)-induced apoptosis in ovarian cancer cells. It can promote epidermal growth factor receptor (EGFR) signaling by interrupting c-Cbl-CIN85 complex and inhibiting EGFR degradation. The BTB/POZ domain, also known as tetramerization (T1) domain, is a versatile protein-protein interaction motif that facilitates homodimerization or heterodimerization. KCTD family BTB domains can adopt a wide range of oligomerization geometries, including homodimerization, tetramerization, and pentamerization.

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1834198877  10 SDLVNLNVGGQRFSTSRQTLTWIPDTFFTALLSGRISSLRDEHNAIFIDRDPTLFSIILNYLRTKDIDIKNCEIRALRHE 89
Cdd:cd18363     1 GDIINLNVGGKRFSTSRQTLTWIPDSFFTSLLSGRISSLKDETGAIFIDRDPKLFSIILNYLRTKEIDLRNVDISSLRHE 80

                  ....*.
gi 1834198877  90 AEYYGI 95
Cdd:cd18363    81 AEFYGI 86

Broad-Complex, Tramtrack and Bric a brac; Domain in Broad-Complex, Tramtrack and Bric a brac. Also known as POZ (poxvirus and zinc finger) domain. Known to be a protein-protein interaction motif found at the N-termini of several C2H2-type transcription factors as well as Shaw-type potassium channels. Known structure reveals a tightly intertwined dimer formed via interactions between N-terminal strand and helix structures. However in a subset of BTB/POZ domains, these two secondary structures appear to be missing. Be aware SMART predicts BTB/POZ domains without the beta1- and alpha1-secondary structures.

                           10        20        30        40        50        60        70        80
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1834198877   13 VNLNVGGQRFSTSRQTLTWIPDTFFTALLSGRISSLRDEHnaIFIDRDPTLFSIILNYLRTKDIDIKNCEIRALRHEAEY 92
Cdd:smart00225   2 VTLVVGGKKFHAHKAVLAAHSPYFKALFSSDFKESDKSEI--YLDDVSPEDFRALLNFLYTGKLDLPEENVEELLELADY 79

                           90
                   ....*....|....*
gi 1834198877   93 YGITPLTKrlaLCED 107
Cdd:smart00225  80 LQIPGLVE---LCEE 91

BTB (Broad-Complex, Tramtrack and Bric a brac)/POZ (poxvirus and zinc finger) domain found in potassium channel tetramerization domain-containing protein 3 (KCTD3) and SH3KBP1-binding protein 1 (SHKBP1); The group of KCTD proteins includes KCTD3 and SHKBP1. KCTD3, also called renal carcinoma antigen NY-REN-45, is a BTB/POZ domain-containing protein that is an accessory subunit of potassium/sodium hyperpolarization-activated cyclic nucleotide-gated channel 3 (HCN3), upregulating its cell-surface expression and current density without affecting its voltage dependence and kinetics. SHKBP1, also called SETA-binding protein 1, interacts with cathepsin B and participates in tumor necrosis factor (TNF)-induced apoptosis in ovarian cancer cells. It can promote epidermal growth factor receptor (EGFR) signaling by interrupting c-Cbl-CIN85 complex and inhibiting EGFR degradation. The BTB/POZ domain, also known as tetramerization (T1) domain, is a versatile protein-protein interaction motif that facilitates homodimerization or heterodimerization. KCTD family BTB domains can adopt a wide range of oligomerization geometries, including homodimerization, tetramerization, and pentamerization.

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1834198877  10 SDLVNLNVGGQRFSTSRQTLTWIPDTFFTALLSGRISSLRDEHNAIFIDRDPTLFSIILNYLRTKDIDIKNCEIRALRHE 89
Cdd:cd18363     1 GDIINLNVGGKRFSTSRQTLTWIPDSFFTSLLSGRISSLKDETGAIFIDRDPKLFSIILNYLRTKEIDLRNVDISSLRHE 80

                  ....*.
gi 1834198877  90 AEYYGI 95
Cdd:cd18363    81 AEFYGI 86

BTB (Broad-Complex, Tramtrack and Bric a brac)/POZ (poxvirus and zinc finger) domain found in potassium channel tetramerization domain-containing protein 3 (KCTD3); KCTD3, also called renal carcinoma antigen NY-REN-45, is a BTB/POZ domain-containing protein that is an accessory subunit of potassium/sodium hyperpolarization-activated cyclic nucleotide-gated channel 3 (HCN3), upregulating its cell-surface expression and current density without affecting its voltage dependence and kinetics. The BTB/POZ domain, also known as tetramerization (T1) domain, is a versatile protein-protein interaction motif that facilitates homodimerization or heterodimerization. KCTD family BTB domains can adopt a wide range of oligomerization geometries, including homodimerization, tetramerization, and pentamerization.

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1834198877  11 DLVNLNVGGQRFSTSRQTLTWIPDTFFTALLSGRISSLRDEHNAIFIDRDPTLFSIILNYLRTKDIDIKNCEIRALRHEA 90
Cdd:cd18392     2 EIIQLNVGGTRFSTSRQTLMWIPDSFFSSLLSGRISSLKDETGAIFIDRDPTAFVPILNFLRTKELDLRGVNINVLRHEA 81

                  ....*..
gi 1834198877  91 EYYGITP 97
Cdd:cd18392    82 EFYGITP 88

BTB/POZ domain; In voltage-gated K+ channels this domain is responsible for subfamily-specific assembly of alpha-subunits into functional tetrameric channels. In KCTD1 this domain functions as a transcriptional repressor. It also mediates homomultimerization of KCTD1 and interaction of KCTD1 with the transcription factor AP-2-alpha.

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1834198877  13 VNLNVGGQRFSTSRQTLTWIPDTFFTALLSGRISSLRDEHNAIFIDRDPTLFSIILNYLRT--KDIDIKNCEIRALRHEA 90
Cdd:pfam02214   1 VKLNVGGTRFETLKSTLTRFPDTRLGRLLELECDDYDDDTNEYFFDRSPKHFETILNFYRTggKLHRPEEVCLDEFLEEA 80

                          90
                  ....*....|....*
gi 1834198877  91 EYYGITPLTkrLALC 105
Cdd:pfam02214  81 EFYGLDELA--LELC 93

BTB (Broad-Complex, Tramtrack and Bric a brac)/POZ (poxvirus and zinc finger) domain found in potassium channel tetramerization domain-containing proteins, KCTD6, KCTD21 and similar proteins; KCTD6, also called KCASH3 (KCTD containing, Cullin3 adaptor, suppressor of Hedgehog 3), is a substrate-specific adaptor of cullin-3, effectively regulating protein levels of the muscle small ankyrin-1 isoform 5 (sAnk1.5). KCTD21, also called KCASH2, functions as a substrate-specific adaptor of cullin-3, promoting the ubiquitination and degradation of histone deacetylase HDAC1, thereby inhibiting the deacetylation-mediated transcriptional activation of the Hedgehog effectors Gli1 and Gli2. The BTB/POZ domain, also known as tetramerization (T1) domain, is a versatile protein-protein interaction motif that facilitates homodimerization or heterodimerization. KCTD family BTB domains can adopt a wide range of oligomerization geometries, including homodimerization, tetramerization, and pentamerization.

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1834198877  11 DLVNLNVGGQRFSTSRQTLTWIPDTFFTALLSGRISSLRDEHNAIFIDRDPTLFSIILNYLRTKDIDIKN--CEIRALRH 88
Cdd:cd18365     1 DIVNLNVGGVHYTTTLATLTRFPDSMLGAMFSGSMPTTRDDQGNYFIDRDGTLFRYILNFLRSSQLSLPEdfKEYDLLLR 80

                          90
                  ....*....|....
gi 1834198877  89 EAEYYGITPLTKRL 102
Cdd:cd18365    81 EADFYQIEPLIEAL 94

BTB (Broad-Complex, Tramtrack and Bric a brac)/POZ (poxvirus and zinc finger) domain found in potassium channel tetramerization domain-containing protein 7 (KCTD7); KCTD7 is a BTB/POZ domain-containing protein that has an impact on K+ fluxes, neurotransmitter synthesis, and neuronal function. It functions as a regulator of potassium conductance in neurons, and is involved in the control of excitability of cortical neurons. Mutations in KCTD7 may cause progressive myoclonus epilepsy (PME). The BTB/POZ domain, also known as tetramerization (T1) domain, is a versatile protein-protein interaction motif that facilitates homodimerization or heterodimerization. KCTD family BTB domains can adopt a wide range of oligomerization geometries, including homodimerization, tetramerization, and pentamerization.

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1834198877  12 LVNLNVGGQRFSTSRQTLTWIPDTFFTALLSGRISSLRDEHNAIFIDRDPTLFSIILNYLRTKDIDIKNcEIRALRHEAE 91
Cdd:cd18366     5 VVPLNVGGMHFTTRLSTLRKYEDSMLAAMFSGRHHIPKDSEGRYFIDRDGSYFGYILNFLRDGDLPPRE-RARAVYKEAQ 83

                  ....*..
gi 1834198877  92 YYGITPL 98
Cdd:cd18366    84 YYGIGPL 90

BTB (Broad-Complex, Tramtrack and Bric a brac)/POZ (poxvirus and zinc finger) domain found in potassium channel tetramerization domain-containing protein 4 (KCTD4); KCTD4 is a BTB/POZ domain-containing protein with an unknown biological function. KCTD proteins play crucial roles in a variety of fundamental biological processes, such as protein ubiquitination and degradation, suppression of proliferation or transcription, cytoskeleton regulation, tetramerization and gating of ion channels and others. Some KCTD proteins are involved in protein ubiquitination as part of the CRL (Cullin RING Ligase) E3 ligases. The BTB/POZ domain, also known as tetramerization (T1) domain, is a versatile protein-protein interaction motif that facilitates homodimerization or heterodimerization. KCTD family BTB domains can adopt a wide range of oligomerization geometries, including homodimerization, tetramerization, and pentamerization.

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1834198877  12 LVNLNVGGQRFSTSRQTLTWIPDTFFTALLSGRISSLRDEHNAIFIDRDPTLFSIILNYLRTKDI----DIKncEIRALR 87
Cdd:cd18364     1 LVTLNVGGYLYITQRQTLTKYPDSFLEGMVNGKIQCTVDADGNYFIDRDGLLFRHVLNFLRNGELllpeGFQ--ENQLLA 78

                  ....*...
gi 1834198877  88 HEAEYYGI 95
Cdd:cd18364    79 LEADFYQL 86

BTB (Broad-Complex, Tramtrack and Bric a brac)/POZ (poxvirus and zinc finger) domain found in potassium channel tetramerization domain-containing protein 9 (KCTD9); KCTD9 is a BTB/POZ domain-containing protein that contributes to liver injury through NK cell activation during hepatitis B virus-induced acute-on-chronic liver failure. It functions as a substrate-specific adaptor of a BCR (BTB-CUL3-RBX1) E3 ubiquitin-protein ligase complex, which mediates the ubiquitination of target proteins, leading to their degradation by the proteasome. The BTB/POZ domain, also known as tetramerization (T1) domain, is a versatile protein-protein interaction motif that facilitates homodimerization or heterodimerization. KCTD family BTB domains can adopt a wide range of oligomerization geometries, including homodimerization, tetramerization, and pentamerization. The KCTD9 BTB domain forms a pentameric structure.

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1834198877  11 DLVNLNVGGQRFSTSRQTLT-WIPDTFFTALLS--GRISSLRDEHNAIFIDRDPTLFSIILNYLRTKDIDI-KNCEIRAL 86
Cdd:cd18368     1 DWIKLNVGGRIFTTTRSTLVkKEPDSMLARMFSddSTWPSSRDENGAYLIDRSPEYFEPILNYLRHGQLILnDGLNPLGV 80

                          90
                  ....*....|....*.
gi 1834198877  87 RHEAEYYGITPLTKRL 102
Cdd:cd18368    81 LEEAKFFGIQSLIEIL 96

BTB (Broad-Complex, Tramtrack and Bric a brac)/POZ (poxvirus and zinc finger) domain found in voltage-gated potassium (Kv) channels and potassium channel tetramerization domain-containing (KCTD) proteins; This family includes two protein groups: voltage-gated potassium (Kv) channels and potassium channel tetramerization domain-containing (KCTD) proteins. Kv channels are membrane proteins with fundamental physiological roles. They are responsible for a variety of electrical phenomena, such as the repolarization of the action potential, spike frequency adaptation, synaptic repolarization, and smooth muscle contraction. KCTD proteins play crucial roles in a variety of fundamental biological processes, such as protein ubiquitination and degradation, suppression of proliferation or transcription, cytoskeleton regulation, tetramerization and gating of ion channels, and others. All family members contain the BTB/POZ domain, also known as tetramerization (T1) domain, which is a versatile protein-protein interaction motif that facilitates homodimerization or heterodimerization.

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1834198877  13 VNLNVGGQRFSTSRQTLTWIPDTFFTALLS-GRISSLRDEHNAIFIDRDPTLFSIILNYLRTKDIDI-KNCEIRALRHEA 90
Cdd:cd18187     1 VVLNVSGTRFVTNRQTLTRHPDTLLGRMFKpGREFTFPNETGEYFIDRDPTVFRTILNYYRTGKLNCpDGISIPDLREEC 80

                  ...
gi 1834198877  91 EYY 93
Cdd:cd18187    81 DFY 83

BTB (Broad-Complex, Tramtrack and Bric a brac)/POZ (poxvirus and zinc finger) domain found in potassium channel regulatory protein (KCNRG); KCNRG, also called potassium channel regulator or protein CLLD4, is an endoplasmic reticulum (ER)-associated tumor suppressor that regulates Kv1 family potassium channel proteins by retaining a fraction of the channels in endomembranes. It contains a BTB/POZ domain, also known as tetramerization (T1) domain, which is a versatile protein-protein interaction motif that facilitates homodimerization or heterodimerization.

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1834198877  11 DLVNLNVGGQRFSTSRQTLTWIPDTFFTALLSGRISSLRDEHNAIFIDRDPTLFSIILNYLRTKDIDIKN--CEIRALRH 88
Cdd:cd18375     1 ELVTLNVGGKKFTTRPSTLRRFPDSRLARMLDGKDQDFKVVNGQFFVDRDGSLFSYILDYLRTGQLTLPTefSDYNRLAR 80

                          90
                  ....*....|
gi 1834198877  89 EAEYYGITPL 98
Cdd:cd18375    81 EAEFYGLYSL 90

BTB (Broad-Complex, Tramtrack and Bric a brac)/POZ (poxvirus and zinc finger) domain found in potassium channel tetramerization domain-containing protein 17 (KCTD17); KCTD17 is a BTB/POZ domain-containing protein that functions as a substrate-adaptor for cullin3-RING ubiquitin ligases that polyubiquitylates trichoplein, a protein involved in ciliogenesis down-regulation. It is a positive regulator of ciliogenesis, playing a crucial role in the initial steps of axoneme extension. A missense mutation in KCTD17 causes autosomal dominant myoclonus-dystonia (M-D). The BTB/POZ domain, also known as tetramerization (T1) domain, is a versatile protein-protein interaction motif that facilitates homodimerization or heterodimerization. KCTD family BTB domains can adopt a wide range of oligomerization geometries, including homodimerization, tetramerization, and pentamerization. The KCTD17 BTB domains form pentamers.

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1834198877  13 VNLNVGGQRFSTSRQTLTWIPDTFFTALLSGR-ISSLRDEHNAIFIDRDPTLFSIILNYLR-TKDIDIKNCEIRALRHEA 90
Cdd:cd18391     3 VRLNVGGTVFLTTRQTLCREQKSFLSRLCQGEeLQSDRDETGAYLIDRDPTYFGPILNFLRhGKLVLDKDMAEEGVLEEA 82

                          90
                  ....*....|
gi 1834198877  91 EYYGITPLTK 100
Cdd:cd18391    83 EFYNIGPLIR 92

BTB (Broad-Complex, Tramtrack and Bric a brac)/POZ (poxvirus and zinc finger) domain found in voltage-gated potassium (Kv) channels; Voltage-gated potassium (Kv) channels are composed of alpha subunits, which form the actual conductance pore, and beta subunits, which are auxiliary proteins that associate with alpha subunits to modulate the activity of the Kv channel. This family includes several groups of alpha subunits such as KCNA/Kv1 family of Shaker-type Kv channels, KCNB/Kv2 family of Shab-type Kv channels, KCNC/Kv3 family of Shaw-type Kv channels, KCND/Kv4 family of Shal-type Kv channels, KCNF/Kv5 subfamily of Kv channels, KCNG/Kv6 subfamily of Kv channels, KCNV/Kv8 subfamily of Kv channels, and KCNS/Kv9 subfamily of Kv channels. Kv alpha subunits form functional homo- or hetero-tetrameric channels (typically with other alpha subunits from the same subfamily) through their BTB/POZ domain, also known as tetramerization (T1) domain, which is a versatile protein-protein interaction motif. KCNQ/Kv7 channels are not included in this family, since they do not contain a BTB/POZ domain.

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1834198877  13 VNLNVGGQRFSTSRQTLTWIPDTFFTALLSGRISSLrDEHNAIFIDRDPTLFSIILNYLRTKDIDI-KN-CEIRALRhEA 90
Cdd:cd18317     1 VVLNVGGTRFELSRSTLLRFPDTRLGKLAKESHAYD-ESTNEYFFDRNPEVFEAILDYYRTGELHLpSNvCPASFKE-EL 78

                  ....
gi 1834198877  91 EYYG 94
Cdd:cd18317    79 EFWG 82

BTB (Broad-Complex, Tramtrack and Bric a brac)/POZ (poxvirus and zinc finger) domain found in potassium channel tetramerization domain-containing protein 14 (KCTD14); KCTD14 is a BTB/POZ domain-containing protein with unknown biological function. KCTD proteins play crucial roles in a variety of fundamental biological processes, such as protein ubiquitination and degradation, suppression of proliferation or transcription, cytoskeleton regulation, tetramerization and gating of ion channels and others. Some KCTD proteins are involved in protein ubiquitination as part of the CRL (Cullin RING Ligase) E3 ligases. The BTB/POZ domain, also known as tetramerization (T1) domain, is a versatile protein-protein interaction motif that facilitates homodimerization or heterodimerization. KCTD family BTB domains can adopt a wide range of oligomerization geometries, including homodimerization, tetramerization, and pentamerization.

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1834198877  10 SDLVNLNVGGQRFSTSRQTLTWIPDTFFTALLSGRISSLRDEHNAIFIDRDPTLFSIILNYLRTKDIDIKNceIRALRHE 89
Cdd:cd18371     1 SQVVSLNVGGHIYTTTLSTLRKFPGSKLAELFNGQPKLRTDSEGRYFIDRDGTYFRYILEYLRTNQVPTQH--IQEVYKE 78

                          90
                  ....*....|...
gi 1834198877  90 AEYYGITPLTKRL 102
Cdd:cd18371    79 ALFYDIEPLVKLL 91

BTB (Broad-Complex, Tramtrack and Bric a brac)/POZ (poxvirus and zinc finger) domain found in potassium channel tetramerization domain-containing proteins, KCTD1 and KCTD15; This subfamily of KCTD proteins includes KCTD1 and KCTD15. KCTD1 is a nuclear BTB/POZ domain-containing protein that acts as a transcriptional repressor and mediates protein-protein interactions through a BTB domain. It represses the transcriptional activity of AP-2 family members, including TFAP2A, TFAP2B and TFAP2C. It also functions as a novel inhibitor of the Wnt signaling pathway. Mutations in KCTD1 cause scalp-ear-nipple (SEN) syndrome. KCTD15 is a BTB/POZ domain-containing protein that plays a role in the regulation of neural crest (NC) formation and other steps in embryonic development. It inhibits AP2 transcriptional activity by interaction with its activation domain. The BTB/POZ domain, also known as tetramerization (T1) domain, is a versatile protein-protein interaction motif that facilitates homodimerization or heterodimerization. KCTD family BTB domains can adopt a wide range of oligomerization geometries, including homodimerization, tetramerization, and pentamerization. The KCTD1 BTB domains form pentamers.

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1834198877  13 VNLNVGGQRFSTSRQTLTWIPDTFFTALLSGRI----SSLRDEHnaiFIDRDPTLFSIILNYLRTKDIDIKN--CEIRAL 86
Cdd:cd18361     1 VHIDVGGHIYTSSLETLTKYPESRLGKLFNGSIpivlDSLKQHY---FIDRDGKMFRHILNFLRTSKLLLPDdfTEFDLL 77

                          90
                  ....*....|....*.
gi 1834198877  87 RHEAEYYGITPLTKRL 102
Cdd:cd18361    78 YEEARYYELQPMVKQL 93

BTB (Broad-Complex, Tramtrack and Bric a brac)/POZ (poxvirus and zinc finger) domain found in potassium channel tetramerization domain-containing protein 12 (KCTD12); KCTD12, also called predominantly fetal expressed T1 domain (Pfetin), is a BTB/POZ domain-containing protein that is an auxiliary subunit of GABAB receptors associated with mood disorders. It regulates agonist potency and kinetics of GABAB receptor signaling. It promotes tumorigenesis by facilitating CDC25B/CDK1/Aurora A-dependent G2/M transition. It also regulates colorectal cancer cell stemness through the ERK pathway. The BTB/POZ domain, also known as tetramerization (T1) domain, is a versatile protein-protein interaction motif that facilitates homodimerization or heterodimerization. KCTD family BTB domains can adopt a wide range of oligomerization geometries, including homodimerization, tetramerization, and pentamerization.

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1834198877  10 SDLVNLNVGGQRFSTSRQTLTWIPDTFFTALLSGRISS--LRDEHNAIFIDRDPTLFSIILNYLRTKDIDIKNC--EIRA 85
Cdd:cd18397     2 PEIVELNVGGQVYVTRHTTLVSVPDSLLWHMFSQQKPGelARDSKGRFFLDRDGFLFRYILDYLRDLQLVLPDYfpERSR 81

                          90
                  ....*....|....*..
gi 1834198877  86 LRHEAEYYGITPLTKRL 102
Cdd:cd18397    82 LQREAEFFQLPELVKRL 98

BTB (Broad-Complex, Tramtrack and Bric a brac)/POZ (poxvirus and zinc finger) domain found in potassium channel tetramerization domain-containing protein 18 (KCTD18); KCTD18 is a BTB/POZ domain-containing protein with with unknown biological function. A duplication of the KCTD18 gene has been found in a patient with epilepsy, developmental delay, and autistic behavior, which may contribute to the phenotype. KCTD proteins play crucial roles in a variety of fundamental biological processes, such as protein ubiquitination and degradation, suppression of proliferation or transcription, cytoskeleton regulation, tetramerization and gating of ion channels and others. Some KCTD proteins are involved in protein ubiquitination as part of the CRL (Cullin RING Ligase) E3 ligases. The BTB/POZ domain, also known as tetramerization (T1) domain, is a versatile protein-protein interaction motif that facilitates homodimerization or heterodimerization. KCTD family BTB domains can adopt a wide range of oligomerization geometries, including homodimerization, tetramerization, and pentamerization.

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1834198877  11 DLVNLNVGGQRFSTSRQTLTWIPDTFFTALLSGRISSLRDEHNAIFIDRDPTLFSIILNYLRTKDIDIKNCEIR-ALRHE 89
Cdd:cd18372     1 DVLRLNVGGCIYTARRESLCRFKDSMLSSMFSGRFPLKLDESGACVIDRDGRLFKYLLDYLHGELQIPEDEQTRlALQEE 80

                          90
                  ....*....|....*..
gi 1834198877  90 AEYYGIT---PLTKRLA 103
Cdd:cd18372    81 ADYFGIPypySLTDHLA 97

BTB (Broad-Complex, Tramtrack and Bric a brac)/POZ (poxvirus and zinc finger) domain found in tumor necrosis factor, alpha-induced protein 1, endothelial (TNFAIP1); TNFAIP1, also called BTB/POZ domain-containing adapter for CUL3-mediated RhoA degradation protein 2 (BACURD2), or protein B12, is a BTB/POZ domain-containing protein that is involved in DNA replication, DNA damage repair and cell apoptosis, and is implicated in human diseases including cancer, Alzheimer's disease (AD) and type 2 diabetic nephropathy. The BTB/POZ domain, also known as tetramerization (T1) domain, is a versatile protein-protein interaction motif that facilitates homodimerization or heterodimerization. KCTD family BTB domains can adopt a wide range of oligomerization geometries, including homodimerization, tetramerization, and pentamerization. The BTB domains of other BACURD subfamily members, KCTD10 and KCTD13, form a novel two-fold symmetric tetramer that is distinct from the tetramer formed by voltage-gated potassium (Kv) channels.

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1834198877  13 VNLNVGGQRFSTSRQTLTWiPDTFFTALLSGRISSLRDEHNAIFIDRDPTLFSIILNYLRTKDIDIKNC--EIRALRHEA 90
Cdd:cd18401     5 VRLNVGGSLYYTTVQVLTR-HDTMLKAMFSGRMEVLTDKEGWILIDRCGKHFGTILNYLRDDTVALPKSrqEIKELMAEA 83

                  ....*...
gi 1834198877  91 EYYGITPL 98
Cdd:cd18401    84 KYYLIQGL 91

BTB (Broad-Complex, Tramtrack and Bric a brac)/POZ (poxvirus and zinc finger) domain found in potassium voltage-gated channel subfamily D member 3 (KCND3); KCND3, also called voltage-gated potassium channel subunit Kv4.3, is a pore-forming subunit of voltage-gated rapidly inactivating A-type potassium channels. Mutations in KCND3 cause spinocerebellar ataxia. Voltage-gated potassium (Kv) channels are composed of alpha subunits, which form the actual conductance pore, and cytoplasmic beta subunits, which are auxiliary proteins that associate with alpha subunits to modulate the activity of the Kv channel. KCND3 is an alpha subunit that forms functional homo- or hetero-tetrameric channels (with other Kv4/KCND alpha subunits) through its BTB/POZ domain, also known as tetramerization (T1) domain, which is a versatile protein-protein interaction motif. It is modulated by cytoplasmic KChIPs/KCNIPs (Kv-channel interacting proteins), which are small calcium binding proteins with EF-hand-like domains.

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1834198877   6 HASSSDLVNLNVGGQRFSTSRQTLTWIPDTFFTAllSGRISSLRDEHNAIFIDRDPTLFSIILNYLRTKDIDIKNCE-IR 84
Cdd:cd18419    30 NKRQDELIVLNVSGRRFQTWRTTLERYPDTLLGS--TEKEFFFNEDTKEYFFDRDPEVFRCVLNFYRTGKLHYPRYEcIS 107

                          90
                  ....*....|...
gi 1834198877  85 ALRHEAEYYGITP 97
Cdd:cd18419   108 AYDEELAFYGILP 120

BTB (Broad-Complex, Tramtrack and Bric a brac)/POZ (poxvirus and zinc finger) domain found in potassium channel tetramerization domain-containing protein 13 (KCTD13); KCTD13, also called BTB/POZ domain-containing adapter for CUL3-mediated RhoA degradation protein 1 (BACURD1), or TNFAIP1-like protein, is a BTB/POZ domain-containing protein that may function as a substrate-specific adaptor of a BCR (BTB-CUL3-RBX1) E3 ubiquitin-protein ligase complex that mediates the ubiquitination of RhoA, leading to its degradation by the proteasome, thereby regulating the actin cytoskeleton and cell migration. The BTB/POZ domain, also known as tetramerization (T1) domain, is a versatile protein-protein interaction motif that facilitates homodimerization or heterodimerization. KCTD family BTB domains can adopt a wide range of oligomerization geometries, including homodimerization, tetramerization, and pentamerization. The KCTD13 BTB domain forms a novel two-fold symmetric tetramer that is distinct from the tetramer formed by voltage-gated potassium (Kv) channels.

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1834198877  10 SDLVNLNVGGQRFSTSRQTLTWiPDTFFTALLSGRISSLRDEHNAIFIDRDPTLFSIILNYLRTKDIDIKNC--EIRALR 87
Cdd:cd18400     1 SKYVKLNVGGSLHYTTVQTLTK-QDTMLKAMFSGRVEVLTDSEGWVLIDRSGRHFGTILNYLRDGSVPLPEStrELEELL 79

                          90
                  ....*....|...
gi 1834198877  88 HEAEYYGITPLTK 100
Cdd:cd18400    80 GEARYYLVQGLVE 92

BTB (Broad-Complex, Tramtrack and Bric a brac)/POZ (poxvirus and zinc finger) domain found in Drosophila melanogaster potassium voltage-gated channel protein Shal and similar proteins; Drosophila melanogaster Shal, also called Shaker cognate l or Shal2, is a transient potassium current (I(A)) channel, which is required for maintaining excitability during repetitive firing and normal locomotion in Drosophila. It may play a role in the nervous system and in the regulation of beating frequency in pacemaker cells. Shal mediates the voltage-dependent potassium ion permeability of excitable membranes. Assuming opened or closed conformations in response to the voltage difference across the membrane, the protein forms a potassium-selective channel through which potassium ions may pass in accordance with their electrochemical gradient. Voltage-gated potassium (Kv) channels are composed of alpha subunits, which form the actual conductance pore, and cytoplasmic beta subunits, which are auxiliary proteins that associate with alpha subunits to modulate the activity of the Kv channel. Shal is an alpha subunit that forms functional homo- or hetero-tetrameric channels (with other alpha subunits) through its BTB/POZ domain, also known as tetramerization (T1) domain, which is a versatile protein-protein interaction motif.

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1834198877  11 DLVNLNVGGQRFSTSRQTLTWIPDTFFTAllSGRISSLRDEHNAIFIDRDPTLFSIILNYLRTKDIDIKNCE-IRALRHE 89
Cdd:cd18420    36 EKLIINVSGRRFETWRNTLEKYPDTLLGS--NEREFFYDEETKEYFFDRDPDIFRHILNYYRTGKLHYPKHEcLTAYDEE 113

                  ....*...
gi 1834198877  90 AEYYGITP 97
Cdd:cd18420   114 LAFFGIMP 121

BTB (Broad-Complex, Tramtrack and Bric a brac)/POZ (poxvirus and zinc finger) domain found in KCNC/Kv3 subfamily of Shaw-type voltage-dependent potassium channels; Voltage-gated potassium (Kv) channels are composed of alpha subunits, which form the actual conductance pore, and cytoplasmic beta subunits, which are auxiliary proteins that associate with alpha subunits to modulate the activity of the Kv channel. The potassium voltage-gated channel subfamily Kv3, also known as subfamily C, contains four alpha subunit members, Kv3.1 (KCNC1), Kv3.2 (KCNC2), Kv3.3 (KCNC3), and Kv3.4 (KCNC4), which are orthologs of the Shaw gene in Drosophila. Unlike other Kv subfamilies, Kv3 channels typically open only at positive potentials and both, activation and deactivation, in response to changes in voltage are very rapid. They are uniquely associated with the ability of certain neurons to fire action potentials and to release neurotransmitter at high rates of up to 1,000 Hz. Kv3/KCNC subfamily alpha subunits form functional homo- or hetero-tetrameric channels (with other alpha subunits) through their BTB/POZ domain, also known as tetramerization (T1) domain, which is a versatile protein-protein interaction motif.

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1834198877  13 VNLNVGGQRFSTSRQTLTWIPDTFFTALLSGRISSLR--DEHNAIFIDRDPTLFSIILNYLRTKDIDIKN--CEiRALRH 88
Cdd:cd18379     1 IVINVGGVRHETYKSTLRNLPDTRLAWLTETEASAFDydPVTGEFFFDRHPGVFAQILNYYRTGKLHCPAdvCG-PLFEE 79

                  ....*...
gi 1834198877  89 EAEYYGIT 96
Cdd:cd18379    80 ELAFWGID 87

BTB (Broad-Complex, Tramtrack and Bric a brac)/POZ (poxvirus and zinc finger) domain found in potassium voltage-gated channel subfamily S member 3 (KCNS3); KCNS3, also called delayed-rectifier K(+) channel alpha subunit 3 or voltage-gated potassium channel subunit Kv9.3, is an alpha subunit of voltage-gated potassium channel linked to tissue oxygenation responses. It can form functional heterotetrameric channels with KCNB1 (also known as Kv2.1), and further modulates the delayed rectifier voltage-gated potassium channel activation and deactivation rates of KCNB1. Voltage-gated potassium (Kv) channels are composed of alpha subunits, which form the actual conductance pore, and cytoplasmic beta subunits, which are auxiliary proteins that associate with alpha subunits to modulate the activity of the Kv channel. KCNS3 is a regulatory alpha subunit that cannot form a functional homo-tetrameric channel. It forms hetero-tetrameric channels (with other functional alpha subunits) through its BTB/POZ domain, also known as tetramerization (T1) domain, which is a versatile protein-protein interaction motif.

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1834198877  11 DLVNLNVGGQRFSTSRQTLTWIPDTFFTALLSGR----ISSLRDEHNAI----FIDRDPTLFSIILNYLRTKDIDIKN-- 80
Cdd:cd18428     1 ELINLNVGGFKQSVDQSTLLRFPHTRLGKLLNCHseeaILELCDDYSVAdkeyYFDRNPSLFRYVLNFYYTGKLHVMEel 80

                          90
                  ....*....|....*...
gi 1834198877  81 CeIRALRHEAEYYGITPL 98
Cdd:cd18428    81 C-VFSFCQEIEYWGINEL 97

BTB (Broad-Complex, Tramtrack and Bric a brac)/POZ (poxvirus and zinc finger) domain found in potassium voltage-gated channel protein Shaw; Shaw, also called Shaw2, is a voltage-gated potassium channel in Drosophila. It mediates transmembrane potassium transport in excitable membranes. Assuming opened or closed conformations in response to the voltage difference across the membrane, the protein forms a tetrameric potassium-selective channel through which potassium ions may pass in accordance with their electrochemical gradient. Voltage-gated potassium (Kv) channels are composed of alpha subunits, which form the actual conductance pore, and cytoplasmic beta subunits, which are auxiliary proteins that associate with alpha subunits to modulate the activity of the Kv channel. Shaw is an alpha subunit that forms functional homo- or hetero-tetrameric channels (with other alpha subunits) through its BTB/POZ domain, also known as tetramerization (T1) domain, which is a versatile protein-protein interaction motif.

                          10        20        30        40        50        60
                  ....*....|....*....|....*....|....*....|....*....|....*....|.
gi 1834198877  13 VNLNVGGQRFSTSRQTLTWIPDTFFTALLSGrISSLRDEHNAIFIDRDPTLFSIILNYLRT 73
Cdd:cd18416     4 VVLNVGGIRHETYKATLKKIPATRLSRLTEA-LANYDPVLNEYFFDRHPGVFAQILNYYRT 63

BTB (Broad-Complex, Tramtrack and Bric a brac)/POZ (poxvirus and zinc finger) domain found in potassium voltage-gated channel subfamily S member 1 (KCNS1); KCNS1, also called delayed-rectifier K(+) channel alpha subunit 1 or voltage-gated potassium channel subunit Kv9.1, is a modulatory alpha subunit of voltage-gated potassium channel that mediates neuropathic pain following nerve injury. It can form functional heterotetrameric channels with KCNB1 (also known as Kv2.1) and KCNB2 (also known as Kv2.2), and further modulates the delayed rectifier voltage-gated potassium channel activation and deactivation rates of KCNB1 and KCNB2. Voltage-gated potassium (Kv) channels are composed of alpha subunits, which form the actual conductance pore, and cytoplasmic beta subunits, which are auxiliary proteins that associate with alpha subunits to modulate the activity of the Kv channel. KCNS1 is a regulatory alpha subunit that cannot form a functional homo-tetrameric channel. It forms hetero-tetrameric channels (with other functional alpha subunits) through its BTB/POZ domain, also known as tetramerization (T1) domain, which is a versatile protein-protein interaction motif.

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1834198877  13 VNLNVGGQRFSTSRQTLTWIPDTFFTALLS----GRISSLRDEHNAI----FIDRDPTLFSIILNYLRTKDIDIKN--Ce 82
Cdd:cd18426     1 ININVGGLKRRLSSSTLSKFPDTRLGRLLScdseESILQICDDYDVSakefYFDRNPGLFPYVLHFYQTGKLHIMEelC- 79

                          90
                  ....*....|....
gi 1834198877  83 IRALRHEAEYYGIT 96
Cdd:cd18426    80 VFSFSQEIEYWGIN 93

BTB (Broad-Complex, Tramtrack and Bric a brac)/POZ (poxvirus and zinc finger) domain superfamily; Proteins in this superfamily are characterized by the presence of a common protein-protein interaction motif of about 100 amino acids, known as the BTB/POZ domain. Members include transcription factors, oncogenic proteins, ion channel proteins, and potassium channel tetramerization domain (KCTD) proteins. They have been identified in poxviruses and many eukaryotes, and have diverse functions, such as transcriptional regulation, chromatin remodeling, protein degradation and cytoskeletal regulation. Many BTB/POZ proteins contain one or two additional domains, such as kelch repeats, zinc-finger domains, FYVE (Fab1, YOTB, Vac1, and EEA1) fingers, or ankyrin repeats, among others. These special additional domains or interaction partners provide unique characteristics and functions to BTB/POZ proteins. In ion channel proteins and KCTD proteins, the BTB/POZ domain is also called the tetramerization (T1) domain.

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1834198877  13 VNLNVGGQRFSTSRQTLTWIPdTFFTALLSGRISSLRDEHnaIFIDR-DPTLFSIILNYLRTKDIDIKNCEIRALRHEAE 91
Cdd:cd01165     1 VVLVVEGEKFHVNKELLAQSS-EYFRALFRGGFRESGQAE--INLRDiSPEDFRALLEFLYGGKRDLDASNLLELLEAAN 77

                  ..
gi 1834198877  92 YY 93
Cdd:cd01165    78 FL 79

BTB (Broad-Complex, Tramtrack and Bric a brac)/POZ (poxvirus and zinc finger) domain found in potassium voltage-gated channel subfamily S member 2 (KCNS2); KCNS2, also called delayed-rectifier K(+) channel alpha subunit 2 or voltage-gated potassium channel subunit Kv9.2, is a modulatory alpha subunit of voltage-gated potassium channel that can form functional heterotetrameric channels with KCNB1 (also known as Kv2.1) and KCNB2 (also known as Kv2.2), and further modulates the delayed rectifier voltage-gated potassium channel activation and deactivation rates of KCNB1 and KCNB2. Voltage-gated potassium (Kv) channels are composed of alpha subunits, which form the actual conductance pore, and cytoplasmic beta subunits, which are auxiliary proteins that associate with alpha subunits to modulate the activity of the Kv channel. KCNS2 is a regulatory alpha subunit that cannot form a functional homo-tetrameric channel. It forms hetero-tetrameric channels (with other functional alpha subunits) through its BTB/POZ domain, also known as tetramerization (T1) domain, which is a versatile protein-protein interaction motif.

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1834198877  13 VNLNVGGQRFSTSRQTLTWIPDTFFTALLSGR----ISSLRDEH----NAIFIDRDPTLFSIILNYLRTKDIDIKN--Ce 82
Cdd:cd18427     2 ISINVGGFKKRLRSHTLLRFPETRLGRLLSCRskesILELCDDYddtkNEFYFDRNPELFPYVLHFYNTGKLHVMGelC- 80

                          90
                  ....*....|....*.
gi 1834198877  83 IRALRHEAEYYGITPL 98
Cdd:cd18427    81 VFSFSQEIEYWGINEF 96

BTB (Broad-Complex, Tramtrack and Bric a brac)/POZ (poxvirus and zinc finger) domain found in KCNG/Kv6 subfamily of potassium voltage-gated channels; Voltage-gated potassium (Kv) channels are composed of alpha subunits, which form the actual conductance pore, and cytoplasmic beta subunits, which are auxiliary proteins that associate with alpha subunits to modulate the activity of the Kv channel. The potassium voltage-gated channel subfamily Kv6, also known as subfamily G, includes KCNG1 (Kv6.1), KCNG2 (Kv6.2 or KCNF2), KCNG3 (Kv6.3) and KCNG4 (Kv6.4), which are regulatory alpha subunits and do not form functional channels on their own. KCNG1 can form functional heterotetrameric channels with KCNB1 (also known as Kv2.1), and further modulates the delayed rectifier voltage-gated potassium channel activation and deactivation rates of KCNB1. KCNG2, also called cardiac potassium channel subunit, can form functional heterodimeric channels with KCNB1, and further modulates channel activity by shifting the threshold and the half-maximal activation to more negative values. KCNG3, also called voltage-gated potassium channel subunit Kv10.1, is an electrically silent modulatory subunit that can form functional heterotetrameric channels with KCNB1, and further promotes a reduction in the rate of activation and inactivation of the delayed rectifier voltage-gated potassium channel KCNB1. KCNG4 is a silent voltage-gated potassium (KvS) channel subunit that can form functional heterotetrameric channels with KCNB1, and further modulates the delayed rectifier voltage-gated potassium channel activation and deactivation rates of KCNB1.

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1834198877  15 LNVGGQRFSTSRQTLTWIPDTFFTALLSGR----ISSLRDEH----NAIFIDRDPTLFSIILNYLRTKDIDI--KNCEIr 84
Cdd:cd18382     3 INVGGARYSLPWSTLDRFPLTRLSRLKACRseddILRVCDDYdverNEFFFDRSPEAFGVILLFLRAGKLRLlrEMCAL- 81

                          90
                  ....*....|.
gi 1834198877  85 ALRHEAEYYGI 95
Cdd:cd18382    82 SFQEELAYWGI 92

BTB (Broad-Complex, Tramtrack and Bric a brac)/POZ (poxvirus and zinc finger) domain found in Drosophila melanogaster potassium voltage-gated channel protein Shab and similar proteins; Shab is a slow delayed rectifier voltage-gated potassium channel in Drosophila. It mediates transmembrane potassium transport in excitable membranes. Assuming opened or closed conformations in response to the voltage difference across the membrane, the protein forms a tetrameric potassium-selective channel through which potassium ions may pass in accordance with their electrochemical gradient. Voltage-gated potassium (Kv) channels are composed of alpha subunits, which form the actual conductance pore, and cytoplasmic beta subunits, which are auxiliary proteins that associate with alpha subunits to modulate the activity of the Kv channel. Shab is an alpha subunit that forms functional homo- or hetero-tetrameric channels (with other alpha subunits) through its BTB/POZ domain, also known as tetramerization (T1) domain, which is a versatile protein-protein interaction motif.

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1834198877  13 VNLNVGGQRFSTSRQTLTWIPDTfftallsgRISSLRD--EHNAI--------------FIDRDPTLFSIILNYLRTKDI 76
Cdd:cd18413     4 VVINVGGVKHEVLWRTLDRMPHT--------RLGKLRDsnTHEAIvelcddysladneyFFDRHPRSFASILNFYRTGKL 75

                          90       100
                  ....*....|....*....|....
gi 1834198877  77 DI--KNCeIRALRHEAEYYGITPL 98
Cdd:cd18413    76 HLveEMC-VLAFSDDLEYWGVDEL 98

BTB (Broad-Complex, Tramtrack and Bric a brac)/POZ (poxvirus and zinc finger) domain found in KCNA/Kv1 subfamily of Shaker-type voltage-dependent potassium channels; Voltage-gated potassium (Kv) channels are composed of alpha subunits, which form the actual conductance pore, and cytoplasmic beta subunits, which are auxiliary proteins that associate with alpha subunits to modulate the activity of the Kv channel. The potassium voltage-gated channel subfamily Kv1, also known as subfamily A, contains eight alpha subunit members, Kv1.1 (KCNA1), Kv1.2 (KCNA2), Kv1.3 (KCNA3), Kv1.4 (KCNA4), Kv1.5 (KCNA5), Kv1.6 (KCNA6), Kv1.7 (KCNA7), and Kv1.8 (KCNA10), which are orthologs of the Shaker gene in Drosophila. They are delayed rectifiers except for Kv1.4 (KCNA4), which is an A-type potassium channel. Delayed rectifiers are slow opening and closing voltage-gated potassium channels. Because of their delayed activation kinetics, they play an important role in controlling action potential duration. A-type channels are fast/rapidly inactivating potassium channels. Kv1/KCNA subfamily alpha subunits form functional homo- or hetero-tetrameric channels (with other Kv1/KCNA alpha subunits) through their BTB/POZ domain, also known as tetramerization (T1) domain, which is a versatile protein-protein interaction motif.

                          10        20        30        40        50        60
                  ....*....|....*....|....*....|....*....|....*....|....*....|...
gi 1834198877  11 DLVNLNVGGQRFSTSRQTLTWIPDTfftaLLSGRISSLR---DEHNAIFIDRDPTLFSIILNY 70
Cdd:cd18377     1 ERVVINVSGLRFETQLKTLAQFPNT----LLGDPNKRMRffdPLRNEYFFDRNRPSFDAILYY 59

BTB (Broad-Complex, Tramtrack and Bric a brac)/POZ (poxvirus and zinc finger) domain found in KCNF/Kv5 subfamily of potassium voltage-gated channels; Voltage-gated potassium (Kv) channels are composed of alpha subunits, which form the actual conductance pore, and cytoplasmic beta subunits, which are auxiliary proteins that associate with alpha subunits to modulate the activity of the Kv channel. The potassium voltage-gated channel subfamily Kv5, also known as subfamily F, only contains KCNF1 (also known as Kv5.1 or kH1), which functions as a regulatory alpha-subunit of voltage-gated potassium channel that when coassembled with Kv2.1 can modulate gating in a physiologically relevant manner. It forms hetero-tetrameric channels (with other alpha subunits) through its BTB/POZ domain, also known as tetramerization (T1) domain, which is a versatile protein-protein interaction motif.

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1834198877  13 VNLNVGGQRFSTSRQTLTWIPDTFFTALLS------GRISSLRDEHNAI----FIDRDPTLFSIILNYLRTKDIDIKN-- 80
Cdd:cd18381     3 IVVNVGGVRQVLYGDVLNRYPETRLAELLNclsggyDAIFSLCDDYDPGkrefYFDRDPDAFKCIIEVYYYGEIHMKKgi 82

                          90
                  ....*....|....*..
gi 1834198877  81 CEIrALRHEAEYYGITP 97
Cdd:cd18381    83 CPI-CFKNEMDFWRVDL 98