Protein Details: β3 (Calcium-activated potassium channel subunit beta-3)

Protein ID

ICDB_Pro_1578

Protein Name

β3 (Calcium-activated potassium channel subunit beta-3)

Gene Name

KCNMB3; KCNMB2; KCNMBL

Organism

Homo sapiens (Human)

Length

279 amino acids

AlphaFoldDB

AF-Q9NPA1-F1-model_v4.pdb

Function

Regulatory subunit of the calcium activated potassium KCNMA1 (maxiK) channel. Modulates the calcium sensitivity and gating kinetics of KCNMA1;thereby contributing to KCNMA1 channel diversity. Alters the functional properties of the current expressed by the KCNMA1 channel. Isoform 2;isoform 3 and isoform 4 partially inactivate the current of KCNBMA. Isoform 4 induces a fast and incomplete inactivation of KCNMA1 channel that is detectable only at large depolarizations. In contrast;isoform 1 does not induce detectable inactivation of KCNMA1. Two or more subunits of KCNMB3 are required to block the KCNMA1 tetramer

Sequence

MDFSPSSELGFHFVAFILLTRHRTAFPASGKKRETDYSDGDPLDVHKRLPSSAGEDRAVMLGFAMMGFSVLMFFLLGTTILKPFMLSIQREESTCTAIHTDIMDDWLDCAFTCGVHCHGQGKYPCLQVFVNLSHPGQKALLHYNEEAVQINPKCFYTPKCHQDRNDLLNSALDIKEFFDHKNGTPFSCFYSPASQSEDVILIKKYDQMAIFHCLFWPSLTLLGGALIVGMVRLTQHLSLLCEKYSTVVRDEVGGKVPYIEQHQFKLCIMRRSKGRAEKS

PDB Structures

Ligand Binding

1. DICL_CP

2. DICL_Pep

Binding Site

Disease

Epilepsy;Familial Focal;With Variable Foci 1 and Warburg Micro Syndrome 2

Location

Isoform 1; isoform 3 and isoform 4 are widely expressed. Isoform 2 is expressed placenta; pancreas; kidney and heart. Isoform 1 and isoform 3 are highly expressed in pancreas and testis.

DOI ID

10.1006/geno.1999.5975; 10.1074/jbc.275.9.6453; 10.1074/jbc.m910187199; 10.1073/pnas.100118597; 10.1016/s0014-5793(00)01584-2; 10.1038/ng1285; 10.1038/nature04728; 10.1523/jneurosci.20-13-04890.2000; 10.1085/jgp.117.6.583; 10.1085/jgp.117.6.607; 10.1152/physiolgenomics.00110.2003; 10.1038/nsb932; 10.1152/nips.01387.2002

RefSeq

NP_001157149.1 [Q9NPA1-5]; NP_055222.3 [Q9NPA1-1]; NP_741979.1 [Q9NPA1-2]; NP_741980.1 [Q9NPA1-4]; NP_741981.1 [Q9NPA1-3]