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 442616774  85 ERVVINVSGLRFETQLRTLNQFPDTLLGDPARRLRYFDPLRNEYFFDRSRPSFDAILYYYQSGGRLRRPVNVPLDVFSEE 164
Cdd:cd18407    1 ERLVINISGLRFETQLRTLSIFPDTLLGDPSRRVRYFDPLRNEYFFDRNRPSFDAILYYYQSGGRLRRPVHVPLDIFLEE 80

                         90       100       110       120
                 ....*....|....*....|....*....|....*....|....*..
gi 442616774 165 IKFYELGDQAINKFREDEGFIKEEERPLPDNEKQRKVWLLFEYPESS 211
Cdd:cd18407   81 IRFYQLGQEAIETFREDEGFIPEEEKPLPSHHFQRQVWLLFEYPESS 127

BTB (Broad-Complex, Tramtrack and Bric a brac)/POZ (poxvirus and zinc finger) domain found in potassium voltage-gated channel subfamily A member 6 (KCNA6); KCNA6, also called voltage-gated potassium channel HBK2 or voltage-gated potassium channel subunit Kv1.6, 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. KCNA6 is distributed primarily in neurons of central and peripheral nervous systems. 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. KCNA6 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 442616774  85 ERVVINVSGLRFETQLRTLNQFPDTLLGDPARRLRYFDPLRNEYFFDRSRPSFDAILYYYQSGGRLRRPVNVPLDVFSEE 164
Cdd:cd18407    1 ERLVINISGLRFETQLRTLSIFPDTLLGDPSRRVRYFDPLRNEYFFDRNRPSFDAILYYYQSGGRLRRPVHVPLDIFLEE 80

                         90       100       110       120
                 ....*....|....*....|....*....|....*....|....*..
gi 442616774 165 IKFYELGDQAINKFREDEGFIKEEERPLPDNEKQRKVWLLFEYPESS 211
Cdd:cd18407   81 IRFYQLGQEAIETFREDEGFIPEEEKPLPSHHFQRQVWLLFEYPESS 127

Ion transport protein; This family contains sodium, potassium and calcium ion channels. This family is 6 transmembrane helices in which the last two helices flank a loop which determines ion selectivity. In some sub-families (e.g. Na channels) the domain is repeated four times, whereas in others (e.g. K channels) the protein forms as a tetramer in the membrane.

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 442616774  214 ARVVAIISVFVILLSIVIFCLETLPEFKHYkvfntttngtkieedevpdITDPFFLIETLCIIWFTFELTVRFLACPNKL 293
Cdd:pfam00520   1 SRYFELFILLLILLNTIFLALETYFQPEEP-------------------LTTVLEILDYVFTGIFTLEMLLKIIAAGFKK 61

                          90       100
                  ....*....|....*....|...
gi 442616774  294 NFCRDVMNVIDIIAIIPYFITLA 316
Cdd:pfam00520  62 RYFRSPWNILDFVVVLPSLISLV 84

BTB (Broad-Complex, Tramtrack and Bric a brac)/POZ (poxvirus and zinc finger) domain found in potassium voltage-gated channel subfamily A member 6 (KCNA6); KCNA6, also called voltage-gated potassium channel HBK2 or voltage-gated potassium channel subunit Kv1.6, 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. KCNA6 is distributed primarily in neurons of central and peripheral nervous systems. 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. KCNA6 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 442616774  85 ERVVINVSGLRFETQLRTLNQFPDTLLGDPARRLRYFDPLRNEYFFDRSRPSFDAILYYYQSGGRLRRPVNVPLDVFSEE 164
Cdd:cd18407    1 ERLVINISGLRFETQLRTLSIFPDTLLGDPSRRVRYFDPLRNEYFFDRNRPSFDAILYYYQSGGRLRRPVHVPLDIFLEE 80

                         90       100       110       120
                 ....*....|....*....|....*....|....*....|....*..
gi 442616774 165 IKFYELGDQAINKFREDEGFIKEEERPLPDNEKQRKVWLLFEYPESS 211
Cdd:cd18407   81 IRFYQLGQEAIETFREDEGFIPEEEKPLPSHHFQRQVWLLFEYPESS 127

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 442616774  85 ERVVINVSGLRFETQLRTLNQFPDTLLGDPARRLRYFDPLRNEYFFDRSRPSFDAILYYYQSGGRLRRPVNVPLDVFSEE 164
Cdd:cd18403    1 ERVVINISGLRFETQLKTLAQFPETLLGDPKKRMRYFDPLRNEYFFDRNRPSFDAILYYYQSGGRLRRPVNVPLDIFSEE 80

                         90
                 ....*....|....*....
gi 442616774 165 IKFYELGDQAINKFREDEG 183
Cdd:cd18403   81 IRFYELGEEAMEMFREDEG 99

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 442616774  84 CERVVINVSGLRFETQLRTLNQFPDTLLGDPARRLRYFDPLRNEYFFDRSRPSFDAILYYYQSGGRLRRPVNVPLDVFSE 163
Cdd:cd18408    5 CERVVLNVAGLRFETRARTLGRFPDTLLGDPARRGRFYDDRRREYFFDRHRPSFDAVLYYYQSGGRLRRPAHVPLDVFLE 84

                         90       100       110
                 ....*....|....*....|....*....|
gi 442616774 164 EIKFYELGDQAINKFREDEGFIKEEERPLP 193
Cdd:cd18408   85 EVAFYGLGAAALARLREDEGCPVPPERPLP 114

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 442616774  85 ERVVINVSGLRFETQLRTLNQFPDTLLGDPARRLRYFDPLRNEYFFDRSRPSFDAILYYYQSGGRLRRPVNVPLDVFSEE 164
Cdd:cd18406    1 ERVIINIAGLRFETQLGTLNQFPDTLLGDPDKRMRYFDPLRNEYFFDRNRPSFDGILYFYQSGGKIRRPVNVSIDVFADE 80

                         90
                 ....*....|....*..
gi 442616774 165 IKFYELGDQAINKFRED 181
Cdd:cd18406   81 IRFYQLGEEAMERFRED 97

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        80
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 442616774  85 ERVVINVSGLRFETQLRTLNQFPDTLLGDPARRLRYFDPLRNEYFFDRSRPSFDAILYYYQSGGRLRRPVNVPLDVFSEE 164
Cdd:cd18409    1 QKVIINIAGLRFETQLKTLDQFPDTLLGDPEKRMKYFDSMRNEYFFDRNRPSFDGILYYYQSGGKIRRPANVPLDVFADE 80

                 ....*..
gi 442616774 165 IKFYELG 171
Cdd:cd18409   81 IIFYELG 87

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 442616774  87 VVINVSGLRFETQLRTLNQFPDTLLGDPARRLR--YFDPLRNEYFFDRSRPSFDAILYYYQSGGRLrRPVNVPLDVFSEE 164
Cdd:cd18187    1 VVLNVSGTRFVTNRQTLTRHPDTLLGRMFKPGRefTFPNETGEYFIDRDPTVFRTILNYYRTGKLN-CPDGISIPDLREE 79

                 ....
gi 442616774 165 IKFY 168
Cdd:cd18187   80 CDFY 83

BTB (Broad-Complex, Tramtrack and Bric a brac)/POZ (poxvirus and zinc finger) domain found in KCND/Kv4 subfamily of Shal-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 Kv4, also known as subfamily D, contains three alpha subunit members, Kv4.1 (KCND1), Kv4.2 (KCND2), and Kv4.3 (KCND3), which are orthologs of the Shal gene in Drosophila. They are A-type potassium channels that mediate the native, fast inactivating (A-type) K+ current (IA) described both in the nervous system (A currents) and the heart (transient outward current). Kv4/KCND subfamily alpha subunits form functional homo- or hetero-tetrameric channels through their BTB/POZ domain, also known as tetramerization (T1) domain, which is a versatile protein-protein interaction motif. They are 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 442616774  86 RVVINVSGLRFETQLRTLNQFPDTLLGDpARRLRYFDPLRNEYFFDRSRPSFDAILYYYQSgGRLRRPVNVPLDVFSEEI 165
Cdd:cd18380    1 RIVINVSGRRFETWKNTLEKYPDTLLGS-TEKEFFYDDDTKEYFFDRDPEIFRHILNFYRT-GKLHYPRHECISAYDDEL 78

                         90
                 ....*....|
gi 442616774 166 KFYELGDQAI 175
Cdd:cd18380   79 AFFGILPEII 88

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 442616774  85 ERVVINVSGLRFETQLRTLNQFPDTLLGDPARRLrYFDPLRNEYFFDRSRPSFDAILYYYQSgGRLRRPVNVPLDVFSEE 164
Cdd:cd18417   35 EILVVNVSGRRFQTWKNTLDRYPDTLLGSSEKEF-FYNEDTQEYFFDRDPEMFRHILNFYRT-GRLHYPRHECIQAFDEE 112

                         90       100
                 ....*....|....*....|.
gi 442616774 165 IKFYEL-----GDQAINKFRE 180
Cdd:cd18417  113 LSFYGIipeiiGDCCLEEYRD 133

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 442616774  76 PIPHDHDFC--ERVVINVSGLRFETQLRTLNQFPDTLLGDPARRLrYFDPLRNEYFFDRSRPSFDAILYYYQSgGRLRRP 153
Cdd:cd18420   25 PVDQERRRTddEKLIINVSGRRFETWRNTLEKYPDTLLGSNEREF-FYDEETKEYFFDRDPDIFRHILNYYRT-GKLHYP 102

                         90
                 ....*....|....*
gi 442616774 154 VNVPLDVFSEEIKFY 168
Cdd:cd18420  103 KHECLTAYDEELAFF 117

BTB (Broad-Complex, Tramtrack and Bric a brac)/POZ (poxvirus and zinc finger) domain found in potassium voltage-gated channel subfamily D member 2 (KCND2); KCND2, also called voltage-gated potassium channel subunit Kv4.2, is a major pore-forming subunit in somatodendritic subthreshold A-type potassium current I(SA) channels. It mediates transmembrane potassium transport in excitable membranes, primarily in 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. KCND2 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 442616774  87 VVINVSGLRFETQLRTLNQFPDTLLGDPARRLrYFDPLRNEYFFDRSRPSFDAILYYYQSgGRLRRPVNVPLDVFSEEIK 166
Cdd:cd18418    2 IVLNVSGTRFQTWRNTLERYPDTLLGSSERDF-FYHEETQEYFFDRDPDIFRHILNFYRT-GKLHYPRHECISAYDEELA 79

                 ..
gi 442616774 167 FY 168
Cdd:cd18418   80 FF 81

BTB (Broad-Complex, Tramtrack and Bric a brac)/POZ (poxvirus and zinc finger) domain found in KCNB/Kv2 subfamily of Shab-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 two alpha subunit members, Kv2.1 (KCNB1) and Kv2.2 (KCNB2), which are orthologs of the Shab gene in Drosophila. They are delayed-rectifier potassium currents in various neurons, although their physiological roles often remain elusive. Kv2/KCNB 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 442616774  86 RVVINVSGLRFETQLRTLNQFPDTLLGdparRLRY-------------FDPLRNEYFFDRSRPSFDAILYYYQSgGRLRR 152
Cdd:cd18378    3 RVLLNVGGVRHEVLWRTLDRLPRTRLG----RLREcnthesllelcddYDLEDNEYFFDRHPGAFTSILNFYRT-GKLHM 77

                         90
                 ....*....|....*.
gi 442616774 153 PVNVPLDVFSEEIKFY 168
Cdd:cd18378   78 PEEMCVLSFSQELEYW 93

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
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*
gi 442616774  86 RVVINVSGLRFETQLRTLNQFPDTLLGdparRLRY-------------FDPLRNEYFFDRSRPSFDAILYYYQSG 147
Cdd:cd18413    3 RVVINVGGVKHEVLWRTLDRMPHTRLG----KLRDsntheaivelcddYSLADNEYFFDRHPRSFASILNFYRTG 73

BTB (Broad-Complex, Tramtrack and Bric a brac)/POZ (poxvirus and zinc finger) domain found in potassium channel tetramerization domain-containing proteins; The potassium channel tetramerization domain (KCTD) family proteins contain the BTB/POZ domain, also known as tetramerization (T1) domain, which is a versatile protein-protein interaction motif that facilitates homodimerization or heterodimerization. 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. Some others show Cullin-independent functions including binding and regulation of GABA (gamma-aminobutyric acid) receptors (KCTD8, KCTD12 and KCTD16) and inhibition of AP-2 function (KCTD15). 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 442616774  87 VVINVSGLRFETQLRTLNQFPDTLLGDPAR-RLRYFDPLRNEYFFDRSRPSFDAILYYYQSGGRLRRPVNVPLDVFSEEI 165
Cdd:cd18316    1 VKLNVGGTLFTTSRSTLLKDPDSLLAALFSgRWPLPRDEDGSIFIDRDPELFRHILNFLRTGKLPLPSDFVELEELLAEA 80

                 ...
gi 442616774 166 KFY 168
Cdd:cd18316   81 EFY 83

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 442616774  85 ERVVINVSGLRFETQLRTLNQFPDTLL---------GDPA----RRLRYFDPLR--NEYFFDRSRPSFDAILYYYQSgGR 149
Cdd:cd18415    2 ERIILNVGGTRHETYRSTLKTLPGTRLallassdpqGDCLtqcsQVGGSDGSPGggNEFFFDRHPGVFAYVLNYYRT-GK 80

                         90
                 ....*....|....*....
gi 442616774 150 LRRPVNVPLDVFSEEIKFY 168
Cdd:cd18415   81 LHCPADVCGPLFEEELAFW 99

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
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....
gi 442616774  87 VVINVSGLRFETQLRTLNQFPDTLLG---------DPARRLRYFDPLRNEYFFDRSRPSFDAILYYYQsGGRLR 151
Cdd:cd18382    1 VIINVGGARYSLPWSTLDRFPLTRLSrlkacrsedDILRVCDDYDVERNEFFFDRSPEAFGVILLFLR-AGKLR 73

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 442616774  86 RVVINVSGLRFETQLRTLNQFPDTLLGDpARRLRYFDPL----------RNEYFFDRSRPSFDAILYYYQSgGRLRRPVN 155
Cdd:cd18411   11 RVKLNVGGLAHEVLWRTLDRLPRTRLGK-LRDCNTHESLmeicddynleENEYFFDRHPGAFTSILNFYRT-GKLHMMEE 88

                         90
                 ....*....|...
gi 442616774 156 VPLDVFSEEIKFY 168
Cdd:cd18411   89 MCALSFSQELDYW 101

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 442616774  85 ERVVINVSGLRFETQLRTLNQFPDTLLgdpARRL----RYFDPLRNEYFFDRSRPSFDAILYYYQSGgrlrrPVNVPLDv 160
Cdd:cd18375    1 ELVTLNVGGKKFTTRPSTLRRFPDSRL---ARMLdgkdQDFKVVNGQFFVDRDGSLFSYILDYLRTG-----QLTLPTE- 71

                         90
                 ....*....|....*.
gi 442616774 161 FSE------EIKFYEL 170
Cdd:cd18375   72 FSDynrlarEAEFYGL 87

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 442616774  82 DFCERVVINVSGLRFETQLRTLNQFPDTLLGdparRLRY-------------FDPLRNEYFFDRSRPSFDAILYYYQSgG 148
Cdd:cd18421    1 DRTRHVIINVGGIKYRIPWTTLEEFPLTRLG----QLKScnnfdeimdicddYDVTCNEFFFDRNPCAFRTILTFLRA-G 75

                 ...
gi 442616774 149 RLR 151
Cdd:cd18421   76 KLR 78

BTB (Broad-Complex, Tramtrack and Bric a brac)/POZ (poxvirus and zinc finger) domain found in KCNS/Kv9 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 Kv9, also known as subfamily S, includes KCNS1 (Kv9.1), KCNS2 (Kv9.2) and KCNS3 (Kv9.3). They are regulatory alpha subunits that cannot form functional homo-tetrameric channels. Both KCNS1 and KCNS2 are delayed-rectifier K(+) channel alpha subunits 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. KCNS3 is a delayed-rectifier K(+) channel alpha subunit linked to tissue oxygenation responses. It 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 442616774  89 INVSGLRFETQLRTLNQFPDTLLG--------DPARRL-RYFDPLRNEYFFDRSRPSFDAILYYYQSgGRLRRPVNVPLD 159
Cdd:cd18384    3 INVGGFRRRLSASALLRFPGTRLGrllachseEAILELcDDYDVAAREFYFDRNPGFFLYVLHFYRT-GKLHVMDELCVF 81

                         90
                 ....*....|....*..
gi 442616774 160 VFSEEIKFYELGDQAIN 176
Cdd:cd18384   82 SFSQEIEYWGINEFFLD 98

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 442616774  87 VVINVSGLRFETQLRTLNQFPDTLLGdparrlRYF--------DPLRNEYFFDRSRPSFDAILYYYQSgGRLRRPVNVP- 157
Cdd:cd18361    1 VHIDVGGHIYTSSLETLTKYPESRLG------KLFngsipivlDSLKQHYFIDRDGKMFRHILNFLRT-SKLLLPDDFTe 73

                         90
                 ....*....|...
gi 442616774 158 LDVFSEEIKFYEL 170
Cdd:cd18361   74 FDLLYEEARYYEL 86

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 442616774  87 VVINVSGLRFETQLRTLNQFPDTLLGdparRLRY-------------FDPLRNEYFFDRSRPSFDAILYYYqSGGRLRRP 153
Cdd:cd18423    4 IIINVGGIKYLMPWSTLDEFPLTRLG----KLKFcssyeeivqicddYDEDTNEFFFDRNPCAFRMIVSFL-AAGKLRLL 78

                         90
                 ....*....|....*
gi 442616774 154 VNVPLDVFSEEIKFY 168
Cdd:cd18423   79 REMCALSFQEELTYW 93

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
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|.
gi 442616774  87 VVINVSGLRFETQLRTLNQFPDTLLGDPARRLRY-----------FDPLRNEYFFDRSRPSFDAIL--YYY 144
Cdd:cd18381    3 IVVNVGGVRQVLYGDVLNRYPETRLAELLNCLSGgydaifslcddYDPGKREFYFDRDPDAFKCIIevYYY 73

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 442616774  83 FCERVVINVSGLRFETQLRTLNQFPDTLL-----GdparrlRYFDPLRNE--YFFDRSRPSFDAILYYYQSGGrlRRPVN 155
Cdd:cd18366    2 FPEVVPLNVGGMHFTTRLSTLRKYEDSMLaamfsG------RHHIPKDSEgrYFIDRDGSYFGYILNFLRDGD--LPPRE 73

                         90
                 ....*....|....*..
gi 442616774 156 VPLDVFsEEIKFYELGD 172
Cdd:cd18366   74 RARAVY-KEAQYYGIGP 89

BTB (Broad-Complex, Tramtrack and Bric a brac)/POZ (poxvirus and zinc finger) domain found in potassium channel tetramerization domain-containing protein 20 (KCTD20); KCTD20, also called potassium channel tetramerization domain containing 20, is a positive regulator of Akt signaling. It may play an important role in regulating the death and growth of some non-nervous and nervous cells. It contains a BTB/POZ domain, a common protein-protein interaction motif of about 100 amino acids. KCTD family BTB domains can adopt a wide range of oligomerization geometries, including homodimerization, tetramerization, and pentamerization.

                         10        20        30        40        50        60        70
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*.
gi 442616774  85 ERVVINVSGLRFETQLRTLNQFPDTLLGdparrlRYFDPLRnEYFFDR-------------SRPSFDAILYYYQSG 147
Cdd:cd18386    3 EKVTLIVDGTRFVVNPQIFTAHPDTMLG------RMFGPGR-EYNFTRpnekgeyeiaegiSCTVFRTVLDYYKTG 71