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K+ voltage-gated channel subfamily B member 1; delayed rectifier K+ channel 1; DRK1; h-DRK1; voltage-gated K+ channel subunit Kv2.1 (KCNB1)
Function:
- mediates voltage-dependent K+ permeability of excitable membranes
- channels open or close in response to the voltage difference across the membrane, letting K+ pass in accordance with their electrochemical gradient
- highly phosphorylated on Ser in the C-terminal
- differential phosphorylation on a subset of Ser allows graded activity-dependent regulation of channel gating
- phosphorylation on Ser-457, Ser-541, Ser-567, Ser-607, Ser-656 & Ser-720 as well as the N-terminal Ser-15 are all regulated by calcineurin-mediated dephosphorylation
- particularly, Ser-607 & Tyr-128 are significant sites of voltage-gated regulation through phosphorylation - dephosphorylation activities
- Tyr-128 can be dephosphorylated by PTpalpha & cyt-PTpepsilon
- phosphorylation levels on Ser-607 are supersensitive to neuronal activity
- phosphorylation on Ser-567 is reduced during postnatal development with low levels at P2 & P5
- levels then increase to reach adult levels by P14
- phosphorylation levels on Ser-564 & Ser-607 are greatly reduced during seizures, by 40% & 85% respectively
- heteromultimer with KCNG2, KCNG3, KCNG4, KCNS1, KCNS2, KCNS3 & KCNV2 (putative)
Structure:
- the segment S4 is probably the voltage-sensor & is characterized by a series of positively charged amino acids at every third position
- the tail may be important in modulation of channel activity &/or targeting of the channel to specific subcellular compartments
- belongs to the K+ channel family, B (Shab) (TC 1.A.1.2) subfamily, Kv2.1/KCNB1 sub-subfamily
Compartment: membrane
General
glycoprotein
K+ channel subfamily B
phosphoprotein
transmembrane 6 protein
Properties
SIZE: entity length = 858 aa
MW = 96 kD
COMPARTMENT: plasma membrane
MOTIF: cytoplasmic domain {1-186}
MOTIF: Ser phosphorylation site {S12}
Ser phosphorylation site {S15}
Tyr phosphorylation site {Y128}
transmembrane domain {187-208}
exoplasmic loop {209-228}
transmembrane domain {229-250}
cytoplasmic loop {251-260}
transmembrane domain {261-282}
exoplasmic loop {283-294}
transmembrane domain {295-316}
cytoplasmic loop {317-330}
transmembrane domain {331-352}
exoplasmic loop {353-392}
MOTIF: peptide motif {377-382}
transmembrane domain {393-414}
cytoplasmic domain {415-858}
MOTIF: Ser phosphorylation site {S457}
Ser phosphorylation site {S484}
Ser phosphorylation site {S496}
Ser phosphorylation site {S503}
serine-rich region {517-520}
MOTIF: serine residue (SEVERAL)
Ser phosphorylation site {S520}
Ser phosphorylation site {S541}
Ser phosphorylation site {S567}
Ser phosphorylation site {S590}
Ser phosphorylation site {S607}
Ser phosphorylation site {S656}
alanine-rich region {701-706}
MOTIF: alanine residue (SEVERAL)
Ser phosphorylation site {S720}
Ser phosphorylation site {S772}
Ser phosphorylation site {S800}
Ser phosphorylation site {S805}
ION-PERMEABILITY: K+
Database Correlations
OMIM 600397
UniProt Q14721
PFAM correlations
Entrez Gene 3745
Kegg hsa:3745
References
UniProt :accession Q14721