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 1269208329  58 KEILVNVGGQRYLLPWSTLDAFPLSRLSRLRLCRSHEEITQLCDDYDEDSQEFFFDRNPSAFGVIVSFLAAGKLVLLREM 137
Cdd:cd18423     2 REIIINVGGIKYLMPWSTLDEFPLTRLGKLKFCSSYEEIVQICDDYDEDTNEFFFDRNPCAFRMIVSFLAAGKLRLLREM 81

                          90       100       110
                  ....*....|....*....|....*....|
gi 1269208329 138 CALSFREELSYWGIEETNLERCCLRKLLKK 167
Cdd:cd18423    82 CALSFQEELTYWGIEEANLERCCLRKLFQK 111

BTB (Broad-Complex, Tramtrack and Bric a brac)/POZ (poxvirus and zinc finger) domain found in potassium voltage-gated channel subfamily G member 4 (KCNG4); KCNG4, also called voltage-gated potassium channel subunit Kv6.4, is a silent voltage-gated potassium (KvS) channel subunit that 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. KCNG4 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 1269208329  58 KEILVNVGGQRYLLPWSTLDAFPLSRLSRLRLCRSHEEITQLCDDYDEDSQEFFFDRNPSAFGVIVSFLAAGKLVLLREM 137
Cdd:cd18423     2 REIIINVGGIKYLMPWSTLDEFPLTRLGKLKFCSSYEEIVQICDDYDEDTNEFFFDRNPCAFRMIVSFLAAGKLRLLREM 81

                          90       100       110
                  ....*....|....*....|....*....|
gi 1269208329 138 CALSFREELSYWGIEETNLERCCLRKLLKK 167
Cdd:cd18423    82 CALSFQEELTYWGIEEANLERCCLRKLFQK 111

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 1269208329   60 ILVNVGGQRYLLPWSTLDAFPLSRLSRLrlcrsheeitQLCDDYDEDSQEFFFDRNPSAFGVIVSFLAAGKLVLLREmCA 139
Cdd:smart00225   2 VTLVVGGKKFHAHKAVLAAHSPYFKALF----------SSDFKESDKSEIYLDDVSPEDFRALLNFLYTGKLDLPEE-NV 70

                           90       100
                   ....*....|....*....|....*...
gi 1269208329  140 LSFREELSYWGIEEtnLERCCLRKLLKK 167
Cdd:smart00225  71 EELLELADYLQIPG--LVELCEEFLLKL 96

BTB (Broad-Complex, Tramtrack and Bric a brac)/POZ (poxvirus and zinc finger) domain found in potassium voltage-gated channel subfamily G member 4 (KCNG4); KCNG4, also called voltage-gated potassium channel subunit Kv6.4, is a silent voltage-gated potassium (KvS) channel subunit that 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. KCNG4 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 1269208329  58 KEILVNVGGQRYLLPWSTLDAFPLSRLSRLRLCRSHEEITQLCDDYDEDSQEFFFDRNPSAFGVIVSFLAAGKLVLLREM 137
Cdd:cd18423     2 REIIINVGGIKYLMPWSTLDEFPLTRLGKLKFCSSYEEIVQICDDYDEDTNEFFFDRNPCAFRMIVSFLAAGKLRLLREM 81

                          90       100       110
                  ....*....|....*....|....*....|
gi 1269208329 138 CALSFREELSYWGIEETNLERCCLRKLLKK 167
Cdd:cd18423    82 CALSFQEELTYWGIEEANLERCCLRKLFQK 111

BTB (Broad-Complex, Tramtrack and Bric a brac)/POZ (poxvirus and zinc finger) domain found in potassium voltage-gated channel subfamily G members, KCNG1 and KCNG2; KCNG1, also called voltage-gated potassium channel subunit Kv6.1 or kH2, functions as a regulatory alpha-subunit of voltage-gated potassium channel that 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 or voltage-gated potassium channel subunit Kv6.2, is a new gamma-subunit of voltage-gated potassium channels that 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. 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. KCNG1 and KCNG2 are regulatory alpha subunits and do not form homomultimers. They form heteromultimers (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 1269208329  60 ILVNVGGQRYLLPWSTLDAFPLSRLSRLRLCRSHEEITQLCDDYDEDSQEFFFDRNPSAFGVIVSFLAAGKLVLLREMCA 139
Cdd:cd18421     6 VIINVGGIKYRIPWTTLEEFPLTRLGQLKSCNNFDEIMDICDDYDVTCNEFFFDRNPCAFRTILTFLRAGKLRLLREMCA 85

                          90       100
                  ....*....|....*....|....*...
gi 1269208329 140 LSFREELSYWGIEETNLERCCLRKLLKK 167
Cdd:cd18421    86 LSFQEELLYWGIEEENLEWCCRRRLLQK 113

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 1269208329  58 KEILVNVGGQRYLLPWSTLDAFPLSRLSRLRLCRSHEEITQLCDDYDEDSQEFFFDRNPSAFGVIVSFLAAGKLVLLREM 137
Cdd:cd18413     2 RRVVINVGGVKHEVLWRTLDRMPHTRLGKLRDSNTHEAIVELCDDYSLADNEYFFDRHPRSFASILNFYRTGKLHLVEEM 81

                          90       100
                  ....*....|....*....|....*.
gi 1269208329 138 CALSFREELSYWGIEETNLERCCLRK 163
Cdd:cd18413    82 CVLAFSDDLEYWGVDELYLESCCQHK 107

BTB (Broad-Complex, Tramtrack and Bric a brac)/POZ (poxvirus and zinc finger) domain found in potassium voltage-gated channel subfamily B member 1 (KCNB1); KCNB1, also called delayed rectifier potassium channel 1 (DRK1) or voltage-gated potassium channel subunit Kv2.1, mediates transmembrane potassium transport in excitable membranes, primarily in the brain, but also in the pancreas and cardiovascular system. 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. KCNB1 is involved in the regulation of the action potential (AP) repolarization, duration and frequency of repetitive AP firing in neurons, muscle cells and endocrine cells and plays a role in homeostatic attenuation of electrical excitability throughout the brain. 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. KCNB1 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 1269208329  58 KEILVNVGGQRYLLPWSTLDAFPLSRLSRLRLCRSHEEITQLCDDYDEDSQEFFFDRNPSAFGVIVSFLAAGKLVLLREM 137
Cdd:cd18411    10 RRVKLNVGGLAHEVLWRTLDRLPRTRLGKLRDCNTHESLMEICDDYNLEENEYFFDRHPGAFTSILNFYRTGKLHMMEEM 89

                          90       100
                  ....*....|....*....|...
gi 1269208329 138 CALSFREELSYWGIEETNLERCC 160
Cdd:cd18411    90 CALSFSQELDYWGIDEIYLESCC 112

BTB (Broad-Complex, Tramtrack and Bric a brac)/POZ (poxvirus and zinc finger) domain found in potassium voltage-gated channel subfamily B member 2 (KCNB2); KCNB2, also called voltage-gated potassium channel subunit Kv2.2, mediates transmembrane potassium transport in excitable membranes, primarily in the brain and smooth muscle cells. 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. KCNB2 contributes to the delayed-rectifier voltage-gated potassium current in cortical pyramidal neurons and smooth muscle cells. 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. KCNB2 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 1269208329  58 KEILVNVGGQRYLLPWSTLDAFPLSRLSRLRLCRSHEEITQLCDDYDEDSQEFFFDRNPSAFGVIVSFLAAGKLVLLREM 137
Cdd:cd18412    17 RRVKINVGGLNHEVLWRTLDRLPRTRLGKLRDCNTHESLLEVCDDYNLNENEYFFDRHPGAFTSILNFYRTGKLHMMEEM 96

                          90       100       110
                  ....*....|....*....|....*....|
gi 1269208329 138 CALSFREELSYWGIEETNLERCCLRKLLKK 167
Cdd:cd18412    97 CALSFGQELDYWGIDEIYLESCCQARYHQK 126

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 1269208329  60 ILVNVGGQRYLLPWSTLDAFPLSRLSRLRLCRsheeitqlCDDYDEDSQEFFFDRNPSAFGVIVSFL-AAGKLVLLREMC 138
Cdd:pfam02214   1 VKLNVGGTRFETLKSTLTRFPDTRLGRLLELE--------CDDYDDDTNEYFFDRSPKHFETILNFYrTGGKLHRPEEVC 72

                          90       100
                  ....*....|....*....|.
gi 1269208329 139 ALSFREELSYWGIEETNLERC 159
Cdd:pfam02214  73 LDEFLEEAEFYGLDELALELC 93

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 1269208329  60 ILVNVGGQRYLLPWSTLDAFPLSRLSRLRLCRSHEEITQLCDDYDEDSQEFFFDRNPSAFGVIVSFLAAGKLVLLREMCA 139
Cdd:cd18428     3 INLNVGGFKQSVDQSTLLRFPHTRLGKLLNCHSEEAILELCDDYSVADKEYYFDRNPSLFRYVLNFYYTGKLHVMEELCV 82

                          90       100
                  ....*....|....*....|.
gi 1269208329 140 LSFREELSYWGIEETNLERCC 160
Cdd:cd18428    83 FSFCQEIEYWGINELFIDSCC 103

BTB (Broad-Complex, Tramtrack and Bric a brac)/POZ (poxvirus and zinc finger) domain found in potassium voltage-gated channel subfamily V member 2 (KCNV2); KCNV2, also called voltage-gated potassium channel subunit Kv8.2, is a modulatory voltage-gated potassium channel alpha subunit that modulates channel activity by shifting the threshold and the half-maximal activation to more negative values. KCNV2 is essential for visual function and cone survival. 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. KCNV2 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 1269208329  62 VNVGGQRYLLPWSTLDAFPLSRLSRLRLCRSHEEITQLCDDYDEDSQEFFFDRNPSAFGVIVSFLAAGKLVLLREMCALS 141
Cdd:cd18425     3 INVGGTSYQISYRVAASYPKTRIGRLATYTDRSRKLDLCDDYNVQNDEYFFDRDPAVFHHIYNFYRTGVLWVKDELCPRN 82

                          90
                  ....*....|....*....
gi 1269208329 142 FREELSYWGIEETNLERCC 160
Cdd:cd18425    83 FLEEINYWGVRIKNTPRCC 101

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 1269208329  60 ILVNVGGQRYLLPWSTLDAFPLSRLSRLrlcrshEEITQLCDDYDEDSQEFFFDRNPSAFGVIVSFLAAGKLVLLREMCA 139
Cdd:cd18379     1 IVINVGGVRHETYKSTLRNLPDTRLAWL------TETEASAFDYDPVTGEFFFDRHPGVFAQILNYYRTGKLHCPADVCG 74

                          90       100
                  ....*....|....*....|.
gi 1269208329 140 LSFREELSYWGIEETNLERCC 160
Cdd:cd18379    75 PLFEEELAFWGIDETQIEPCC 95

BTB (Broad-Complex, Tramtrack and Bric a brac)/POZ (poxvirus and zinc finger) domain found in potassium voltage-gated channel subfamily C members KCNC1 and KCNC3; KCNC1 (also called NGK2, voltage-gated potassium channel subunit Kv3.1, or voltage-gated potassium channel subunit Kv4) and KCNC3 (also called KSHIIID or voltage-gated potassium channel subunit Kv3.3) play important roles in the rapid repolarization of fast-firing brain neurons. Assuming opened or closed conformations in response to the voltage difference across the membrane, the proteins form tetrameric potassium-selective channels 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. KCNC1 and KCNC3 are alpha subunit that 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 1269208329  59 EILVNVGGQRYLLPWSTLDAFPLSRLSRLRLCRSHEEItqlcdDYDEDSQEFFFDRNPSAFGVIVSFLAAGKLVLLREMC 138
Cdd:cd18414     4 RIVINVGGTRHETYRSTLRTLPGTRLAWLAEPDAHSNF-----DYDPRADEFFFDRHPGVFAHILNYYRTGKLHCPADVC 78

                          90       100
                  ....*....|....*....|..
gi 1269208329 139 ALSFREELSYWGIEETNLERCC 160
Cdd:cd18414    79 GPLYEEELAFWGIDETDVEPCC 100

BTB (Broad-Complex, Tramtrack and Bric a brac)/POZ (poxvirus and zinc finger) domain found in potassium voltage-gated channel subfamily C members KCNC2 and KCNC4; KCNC2, also called Shaw-like potassium channel or voltage-gated potassium channel Kv3.2, is a delayed rectifier voltage-gated potassium channel that mediates transmembrane potassium transport in excitable membranes, primarily in the brain. It contributes to the regulation of the fast action potential repolarization and in sustained high-frequency firing in neurons of the central nervous system. KCNC4, also called KSHIIIC or voltage-gated potassium channel subunit Kv3.4, is a novel high-voltage-activating, tetraethylammonium (TEA)-sensitive, type-A potassium channel that mediates the voltage-dependent potassium ion permeability of excitable membranes. It plays a pivotal role in oxidative stress-related neural cell damage as an oxidation-sensitive channel. 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. KCNC2 and KCNC4 are alpha subunit that 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 1269208329  60 ILVNVGGQRYLLPWSTLDAFPLSRLSRLR------LCRSHEEITQLCDDYDEDSQEFFFDRNPSAFGVIVSFLAAGKLVL 133
Cdd:cd18415     4 IILNVGGTRHETYRSTLKTLPGTRLALLAssdpqgDCLTQCSQVGGSDGSPGGGNEFFFDRHPGVFAYVLNYYRTGKLHC 83

                          90       100
                  ....*....|....*....|....*..
gi 1269208329 134 LREMCALSFREELSYWGIEETNLERCC 160
Cdd:cd18415    84 PADVCGPLFEEELAFWGIDETDVEPCC 110

BTB (Broad-Complex, Tramtrack and Bric a brac)/POZ (poxvirus and zinc finger) domain found in potassium voltage-gated channel subfamily D member 1 (KCND1); KCND1, also called voltage-gated potassium channel subunit Kv4.1, is a pore-forming subunit of voltage-gated rapidly inactivating A-type potassium channels. It may contribute to I (To) current in heart and I (Sa) current in neurons. Its properties are modulated by interactions with other alpha subunits and with regulatory subunits. 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. KCND1 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 1269208329  59 EIL-VNVGGQRYLLPWSTLDAFPLSRLSRlrlcrSHEEITqlcddYDEDSQEFFFDRNPSAFGVIVSFLAAGKLVLLREM 137
Cdd:cd18417    35 EILvVNVSGRRFQTWKNTLDRYPDTLLGS-----SEKEFF-----YNEDTQEYFFDRDPEMFRHILNFYRTGRLHYPRHE 104

                          90       100
                  ....*....|....*....|....*.
gi 1269208329 138 CALSFREELSYWGIEETNLERCCLRK 163
Cdd:cd18417   105 CIQAFDEELSFYGIIPEIIGDCCLEE 130

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 1269208329  60 ILVNVGGQRYLLPWSTLDAFPLSRLSRLrlCRSHEEITqlcddYDEDSQEFFFDRNPSAFGVIVSFLAAGKLVLLREMCA 139
Cdd:cd18187     1 VVLNVSGTRFVTNRQTLTRHPDTLLGRM--FKPGREFT-----FPNETGEYFIDRDPTVFRTILNYYRTGKLNCPDGISI 73

                          90
                  ....*....|
gi 1269208329 140 LSFREELSYW 149
Cdd:cd18187    74 PDLREECDFY 83

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 1269208329  58 KEILVNVGGQRYLLPWSTLDAFPLSRLSrlrlcrSHEEITQlcddYDEDSQEFFFDRNPSAFGVIVSFLAAGKLVLLREM 137
Cdd:cd18420    36 EKLIINVSGRRFETWRNTLEKYPDTLLG------SNEREFF----YDEETKEYFFDRDPDIFRHILNYYRTGKLHYPKHE 105

                          90       100
                  ....*....|....*....|...
gi 1269208329 138 CALSFREELSYWGIEETNLERCC 160
Cdd:cd18420   106 CLTAYDEELAFFGIMPDIIGDCC 128

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 1269208329   60 ILVNVGGQRYLLPWSTLDAFPLSRLSRLrlcrsheeitQLCDDYDEDSQEFFFDRNPSAFGVIVSFLAAGKLVLLREmCA 139
Cdd:smart00225   2 VTLVVGGKKFHAHKAVLAAHSPYFKALF----------SSDFKESDKSEIYLDDVSPEDFRALLNFLYTGKLDLPEE-NV 70

                           90       100
                   ....*....|....*....|....*...
gi 1269208329  140 LSFREELSYWGIEEtnLERCCLRKLLKK 167
Cdd:smart00225  71 EELLELADYLQIPG--LVELCEEFLLKL 96

BTB (Broad-Complex, Tramtrack and Bric a brac)/POZ (poxvirus and zinc finger) domain found in potassium channel tetramerization domain-containing protein 2 (KCTD2); KCTD2 is a BTB/POZ domain-containing protein that functions as an adaptor of Cullin3 E3 ubiquitin ligase. It suppresses gliomagenesis by destabilizing c-Myc. 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. KCTD5 and KCTD17 BTB domain, highly similar to KCTD2, form pentamer structures.

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1269208329  58 KEILVNVGGQRYLLPWSTLDAFPLSRLSRLrlCrshEEITQLCDDYDEdSQEFFFDRNPSAFGVIVSFLAAGKLVLLREM 137
Cdd:cd18389     1 KWVRLNVGGTYFVSTKQTLCRDPKSFLYRL--C---QEDPDLDSDKDE-TGAYLIDRDPTYFGPILNYLRHGKLIINKEL 74

                          90
                  ....*....|....
gi 1269208329 138 CALSFREELSYWGI 151
Cdd:cd18389    75 AEEGVLEEAEFYNI 88

BTB (Broad-Complex, Tramtrack and Bric a brac)/POZ (poxvirus and zinc finger) domain found in potassium channel tetramerization domain-containing proteins KCTD2, KCTD5, and KCTD17, and similar proteins; This subfamily includes potassium channel tetramerization domain-containing proteins KCTD2, KCTD5, and KCTD17, all of which function as adaptors of Cullin3 based ubiquitin E3 ubiquitin ligases. KCTD2 suppresses gliomagenesis by destabilizing c-Myc. KCTD5 is a negative regulator of the AKT pathway, a key signaling cascade frequently deregulated in cancer. KCTD5 does not impact the operation of Kv4.2, Kv3.4, Kv2.1, or Kv1.2 channels. KCTD17 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. KCTD5 and KCTD17 BTB domains form pentamer structures.

                          10        20        30        40        50        60        70
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*...
gi 1269208329  60 ILVNVGGQRYLLPWSTLDAFPLSRLSRLrlCRSHEEitqLCDDYDEdSQEFFFDRNPSAFGVIVSFLAAGKLVLLREM 137
Cdd:cd18362     2 VKLNVGGTYFLTTRTTLCRDPKSFLCRL--CQEDPD---LPSDKDE-TGAYLIDRDPTYFGPILNYLRHGKLIIDKDL 73

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
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*...
gi 1269208329  60 ILVNVGGQRYLLPWSTLDAFPLSRLSRlrlcrsheeitqLCDDYDED----SQEFFFDRNPSAFGVIVSFLAAGKLVL 133
Cdd:cd18375     3 VTLNVGGKKFTTRPSTLRRFPDSRLAR------------MLDGKDQDfkvvNGQFFVDRDGSLFSYILDYLRTGQLTL 68

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 1269208329  60 ILVNVGGQRYLLPWSTLDAFPLSRLSRLRLCRsheeITQLCDDYDEdsqeFFFDRNPSAFGVIVSFLAAgKLVLLREMCA 139
Cdd:cd18363     4 INLNVGGKRFSTSRQTLTWIPDSFFTSLLSGR----ISSLKDETGA----IFIDRDPKLFSIILNYLRT-KEIDLRNVDI 74

                          90
                  ....*....|..
gi 1269208329 140 LSFREELSYWGI 151
Cdd:cd18363    75 SSLRHEAEFYGI 86

BTB (Broad-Complex, Tramtrack and Bric a brac)/POZ (poxvirus and zinc finger) domain found in potassium voltage-gated channel subfamily A member 5 (KCNA5); KCNA5, also called HPCN1, voltage-gated potassium channel HK2, or voltage-gated potassium channel subunit Kv1.5, 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. KCNA5 may play a role in regulating the secretion of insulin in normal pancreatic islets. 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. KCNA5 is an alpha subunit that forms functional homo- or hetero-tetrameric channels (with other Kv1/KCNA 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 1269208329  58 KEILVNVGGQRYLLPWSTLDAFPLSRL----SRLRLcrsheeitqlcddYDEDSQEFFFDRN-PSAFGVIVSFLAAGKLV 132
Cdd:cd18406     1 ERVIINIAGLRFETQLGTLNQFPDTLLgdpdKRMRY-------------FDPLRNEYFFDRNrPSFDGILYFYQSGGKIR 67

                          90       100
                  ....*....|....*....|....*.
gi 1269208329 133 LLREMCALSFREELSYWGIEETNLER 158
Cdd:cd18406    68 RPVNVSIDVFADEIRFYQLGEEAMER 93

BTB (Broad-Complex, Tramtrack and Bric a brac)/POZ (poxvirus and zinc finger) domain found in potassium voltage-gated channel subfamily A member 7 (KCNA7); KCNA7, also called voltage-gated potassium channel subunit Kv1.7, 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. KCNA7 plays an important role in the repolarization of cell membranes. 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. KCNA7 is an alpha subunit that forms functional homo- or hetero-tetrameric channels (with other Kv1/KCNA 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 1269208329  53 PEANLKEILVNVGGQRYLLPWSTLDAFPLSRLSRLRLCRSHeeitqlcddYDEDSQEFFFDRNPSAFGVIVSFL-AAGKL 131
Cdd:cd18408     1 PCGCCERVVLNVAGLRFETRARTLGRFPDTLLGDPARRGRF---------YDDRRREYFFDRHRPSFDAVLYYYqSGGRL 71

                          90       100
                  ....*....|....*....|....*..
gi 1269208329 132 VLLREMCALSFREELSYWGIEETNLER 158
Cdd:cd18408    72 RRPAHVPLDVFLEEVAFYGLGAAALAR 98

BTB (Broad-Complex, Tramtrack and Bric a brac)/POZ (poxvirus and zinc finger) domain found in Drosophila melanogaster potassium voltage-gated channel protein Shaker and similar proteins; Shaker, also termed protein minisleep, represents a family of putative potassium channel proteins in the nervous system of Drosophila. It is a voltage-gated potassium channel that 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. Shaker plays a role in the regulation of sleep need or efficiency. 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. Shaker 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 1269208329  58 KEILVNVGGQRYLLPWSTLDAFPLSRLS----RLRLcrsheeitqlcddYDEDSQEFFFDRNPSAFGVIVSFLAAGKLVL 133
Cdd:cd18410     1 ERVVINVSGLRFETQLKTLNQFPDTLLGdpqrRNRY-------------YDPLRNEYFFDRNRPSFDAILYYYQSGGRLR 67

                          90       100
                  ....*....|....*....|....*.
gi 1269208329 134 LREMCALS-FREELSYWGIEETNLER 158
Cdd:cd18410    68 RPVNVPLDvFSEEIKFYELGENAFEK 93

BTB (Broad-Complex, Tramtrack and Bric a brac)/POZ (poxvirus and zinc finger) domain found in potassium voltage-gated channel subfamily A members 2 (KCNA2) and 3 (KCNA3); KCNA2 is also called NGK1, voltage-gated K(+) channel HuKIV, voltage-gated potassium channel HBK5, or voltage-gated potassium channel subunit Kv1.2. KCNA3 is also called HGK5, HLK3, HPCN3, voltage-gated K(+) channel HuKIII, or voltage-gated potassium channel subunit Kv1.3. KCNA2 and KCNA3 mediate 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. KCNA2 primarily functions in the brain and the central nervous system, but also in the cardiovascular system. It prevents aberrant action potential firing and regulates neuronal output. 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. KCNA2 and KCNA3 are alpha subunits that 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        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1269208329  58 KEILVNVGGQRYLLPWSTLDAFPLSRLS----RLRLcrsheeitqlcddYDEDSQEFFFDRNPSAFGVIVSFLAAGKLVL 133
Cdd:cd18403     1 ERVVINISGLRFETQLKTLAQFPETLLGdpkkRMRY-------------FDPLRNEYFFDRNRPSFDAILYYYQSGGRLR 67

                          90       100
                  ....*....|....*....|....*
gi 1269208329 134 LREMCALS-FREELSYWGIEETNLE 157
Cdd:cd18403    68 RPVNVPLDiFSEEIRFYELGEEAME 92

BTB (Broad-Complex, Tramtrack and Bric a brac)/POZ (poxvirus and zinc finger) domain found in potassium voltage-gated channel subfamily A member 10 (KCNA10); KCNA10, also called voltage-gated potassium channel subunit Kv1.8, is a cyclic nucleotide-gated, voltage-activated potassium channel that 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. KCNA10 is expressed in proximal tubular cells, glomerular and vascular endothelial cells, as well as in vascular smooth muscle cells. It may facilitate proximal tubular sodium absorption by stabilizing cell membrane voltage. The channel activity is up-regulated by cAMP. 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. KCNA10 is an alpha subunit that forms functional homotetrameric channels 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
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*
gi 1269208329  58 KEILVNVGGQRYLLPWSTLDAFPLSRLSrlrlcrsheEITQLCDDYDEDSQEFFFDRN-PSAFGVIVSFLAAGKL 131
Cdd:cd18409     1 QKVIINIAGLRFETQLKTLDQFPDTLLG---------DPEKRMKYFDSMRNEYFFDRNrPSFDGILYYYQSGGKI 66