Biology:KCNJ4

Generic protein structure example

Potassium inwardly-rectifying channel, subfamily J, member 4, also known as KCNJ4 or K_ir2.3, is a human gene.

Function

Several different potassium channels are known to be involved with electrical signaling in the nervous system. One class is activated by depolarization whereas a second class is not. The latter are referred to as inwardly rectifying K+ channels, and they have a greater tendency to allow potassium to flow into the cell rather than out of it. This asymmetry in potassium ion conductance plays a key role in the excitability of muscle cells and neurons. The protein encoded by this gene is an integral membrane protein and member of the inward rectifier potassium channel family. The encoded protein has a small unitary conductance compared to other members of this protein family. Two transcript variants encoding the same protein have been found for this gene.

Interactions

KCNJ4 has been shown to interact with:

• CASK,
• DLG1
• DLG4,
• LIN7B, and
• LIN7C.

See also

• Inward-rectifier potassium ion channel

Further reading

• "International Union of Pharmacology. LIV. Nomenclature and molecular relationships of inwardly rectifying potassium channels.". Pharmacol. Rev. 57 (4): 509–26. 2006. doi:10.1124/pr.57.4.11. PMID 16382105. 
• "Assignment of the human hippocampal inward rectifier potassium channel (HIR) gene to 22q13.1.". Genomics 26 (3): 625–9. 1995. doi:10.1016/0888-7543(95)80189-S. PMID 7607694. 
• "Primary structure and characterization of a small-conductance inwardly rectifying potassium channel from human hippocampus.". Proc. Natl. Acad. Sci. U.S.A. 91 (13): 6240–4. 1994. doi:10.1073/pnas.91.13.6240. PMID 8016146. Bibcode: 1994PNAS...91.6240P. 
• "Cloning a novel human brain inward rectifier potassium channel and its functional expression in Xenopus oocytes.". FEBS Lett. 348 (3): 239–43. 1994. doi:10.1016/0014-5793(94)00612-1. PMID 8034048. 
• "Cloning and expression of a novel human brain inward rectifier potassium channel.". J. Biol. Chem. 269 (32): 20468–74. 1994. doi:10.1016/S0021-9258(17)32016-1. PMID 8051145. 
• "Binding of the inward rectifier K+ channel Kir 2.3 to PSD-95 is regulated by protein kinase A phosphorylation.". Neuron 17 (4): 759–67. 1996. doi:10.1016/S0896-6273(00)80207-X. PMID 8893032. 
• "Inhibition of an inward rectifier potassium channel (Kir2.3) by G-protein betagamma subunits.". J. Biol. Chem. 271 (50): 32301–5. 1997. doi:10.1074/jbc.271.50.32301. PMID 8943291. 
• "Suppression of Kir2.3 activity by protein kinase C phosphorylation of the channel protein at threonine 53.". J. Biol. Chem. 274 (17): 11643–6. 1999. doi:10.1074/jbc.274.17.11643. PMID 10206975. 
• "Neuronal interleukin-16 (NIL-16): a dual function PDZ domain protein.". J. Neurosci. 19 (18): 7770–80. 1999. doi:10.1523/JNEUROSCI.19-18-07770.1999. PMID 10479680. 
• "The DNA sequence of human chromosome 22.". Nature 402 (6761): 489–95. 1999. doi:10.1038/990031. PMID 10591208. Bibcode: 1999Natur.402..489D. 
• "Neuronal inwardly rectifying K(+) channels differentially couple to PDZ proteins of the PSD-95/SAP90 family.". J. Neurosci. 20 (1): 156–62. 2000. doi:10.1523/JNEUROSCI.20-01-00156.2000. PMID 10627592. 
• "Inward rectifier potassium channel Kir2.2 is associated with synapse-associated protein SAP97.". J. Cell Sci. 114 (Pt 5): 987–98. 2001. doi:10.1242/jcs.114.5.987. PMID 11181181. 
• "Direct activation of an inwardly rectifying potassium channel by arachidonic acid.". Mol. Pharmacol. 59 (5): 1061–8. 2001. doi:10.1124/mol.59.5.1061. PMID 11306688. 
• "Transforming growth factor-beta 1 regulates Kir2.3 inward rectifier K+ channels via phospholipase C and protein kinase C-delta in reactive astrocytes from adult rat brain.". J. Biol. Chem. 277 (3): 1974–80. 2002. doi:10.1074/jbc.M107984200. PMID 11713246. 
• "Basolateral membrane expression of the Kir 2.3 channel is coordinated by PDZ interaction with Lin-7/CASK complex.". Am. J. Physiol., Cell Physiol. 282 (1): C183–95. 2002. doi:10.1152/ajpcell.00249.2001. PMID 11742811. 
• "Inward rectifier K+ channel Kir2.3 is localized at the postsynaptic membrane of excitatory synapses.". Am. J. Physiol., Cell Physiol. 282 (6): C1396–403. 2002. doi:10.1152/ajpcell.00615.2001. PMID 11997254. 
• "Heteromerization of Kir2.x potassium channels contributes to the phenotype of Andersen's syndrome.". Proc. Natl. Acad. Sci. U.S.A. 99 (11): 7774–9. 2002. doi:10.1073/pnas.102609499. PMID 12032359. Bibcode: 2002PNAS...99.7774P. 
• "Generation and initial analysis of more than 15,000 full-length human and mouse cDNA sequences.". Proc. Natl. Acad. Sci. U.S.A. 99 (26): 16899–903. 2003. doi:10.1073/pnas.242603899. PMID 12477932. Bibcode: 2002PNAS...9916899M. 
• "A multiprotein trafficking complex composed of SAP97, CASK, Veli, and Mint1 is associated with inward rectifier Kir2 potassium channels.". J. Biol. Chem. 279 (18): 19051–63. 2004. doi:10.1074/jbc.M400284200. PMID 14960569. 
• "Protein trafficking and anchoring complexes revealed by proteomic analysis of inward rectifier potassium channel (Kir2.x)-associated proteins.". J. Biol. Chem. 279 (21): 22331–46. 2004. doi:10.1074/jbc.M400285200. PMID 15024025. 

External links

• KCNJ4+protein,+human at the US National Library of Medicine Medical Subject Headings (MeSH)

This article incorporates text from the United States National Library of Medicine, which is in the public domain.