Kv channel-interacting protein 2; KChIP2; A-type K+ channel modulatory protein 2; K+ channel-interacting protein 2; cardiac voltage gated K+ channel modulatory subunit (KCNIP2, KCHIP2)

Function

• regulatory subunit of Kv4/D (Shal)-type voltage-gated rapidly inactivating A-type K+ channels
• modulates channels density, inactivation kinetics & rate of recovery from inactivation
• Ca+2-dependent
• in vitro, modulates Kv4.2 & Kv4.3 currents
• Kv4.2 & Kv4.3 trafficking to the cell surface
• component of heteromultimeric K+ channels; Kv4.2/KCNIP2 channel complex contains 4 Kv4.2 & 4 KCNIP2 subunits
• isoform 1 & isoform 3 interact with Kv4.3 isoform 1
• involved in KCND2 & KCND3 trafficking to the cell surface
• may be required for the expression of I(To) currents in the heart

Structure

• at least isoform 2 & isoform 3 can self-associate to form homodimers & homotetramers
• belongs to the recoverin family
• contains 4 EF-hand domains

Compartment

• cell membrane, lipid-anchor (palmitate)
• palmitoylation enhances association with plasma membrane

Alternative splicing

named isoforms=9

Expression

• expressed in brain

colocalizes with Kv4.2 in excitatory neurons including cortical & hippocampal CA1 pyramidal cells

• isoform 3 is expressed in heart, umbilical vein endothelial cells
• not expressed in fetal heart

More general terms

• membrane protein
• Ca+2 binding protein

Component of

• Kv4.2/KCNIP2 channel complex

Database

• Entrez gene: http://www.ncbi.nlm.nih.gov/sites/entrez?db=gene&cmd=Retrieve&dopt=Graphics&list_uids=30819
• Kegg: http://www.genome.jp/dbget-bin/www_bget?hsa:30819
• OMIM: https://mirror.omim.org/entry/604661
• UniProt: http://www.uniprot.org/uniprot/Q9NS61.html