K+ voltage-gated channel subfamily D member 3; voltage-gated K+ channel subunit Kv4.3 (KCND3)

Function

• pore-forming (alpha) subunit of voltage-gated rapidly inactivating A-type K+ channels
• may contribute to I(To) current in heart & I(Sa) current in neurons
• channel properties are modulated by interactions with other alpha subunits & with regulatory subunits
• homotetramer or heterotetramer with KCND1 &/or KCND2
• associates with the regulatory subunits KCNIP1, KCNIP2, KCNIP3 & KCNIP4 (putative)
• interacts with KCNE1, KCNE2, SCN1B & KCNAB1 & DLG1

Structure

• the segment S4 is probably the voltage-sensor & is characterized by a series of positively charged amino acids at every third position
• belongs to the K+ channel family, D (Shal) (TC 1.A.1.2) subfamily, Kv4.3/KCND3 sub-subfamily

Compartment

• membrane, cell membrane, sarcolemma (putative)

Alternative splicing

named isoforms=2

Expression

• highly expressed in heart & brain, in particular in cerebral cortex, cerebellum, amygdala & caudate nucleus
• detected at lower levels in liver, skeletal muscle, kidney & pancreas
• isoform 1 predominates in most tissues
• isoform 1 & isoform 2 are detected at similar levels in brain, skeletal muscle & pancreas

More general terms

• transmembrane 6 protein
• K+ channel subfamily D
• phosphoprotein

Database

• Entrez gene: http://www.ncbi.nlm.nih.gov/sites/entrez?db=gene&cmd=Retrieve&dopt=Graphics&list_uids=3752
• Kegg: http://www.genome.jp/dbget-bin/www_bget?hsa:3752
• OMIM: https://mirror.omim.org/entry/605411
• UniProt: http://www.uniprot.org/uniprot/Q9UK17.html