Biology:KCNJ15
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Potassium inwardly-rectifying channel, subfamily J, member 15, also known as KCNJ15 is a human gene, which encodes the Kir4.2 protein.[1]
Function
Potassium channels are present in most mammalian cells, where they participate in a wide range of physiologic responses. Kir4.2 is an integral membrane protein and inward-rectifier type potassium channel. Kir4.2 has a greater tendency to allow potassium to flow into a cell rather than out of a cell. Three transcript variants encoding the same protein have been found for this gene.[1]
The existing literature describing KCNJ15 and Kir4.2 is sparse. In spite of some initial channel nomenclature confusion, in which the gene was referred to as Kir1.3[2] the channel was first cloned from human kidney by Shuck and coworkers in 1997.[3] Shortly thereafter it was shown that mutation of an extracellular lysine residue resulted in 6-fold increase in K+ current.[4] Two years later, in 1999, voltage clamp measurements in xenopus oocytes found that intracellular acidification decreased the potassium current of Kir4.2. Also activation of protein kinase C decreased the current although in a non-reversible fashion. Furthermore, it was found that coexpression with related potassium channel Kir5.1, changed these results somewhat, which the authors concluded was likely to be a result of heterodimerization.[2] Further voltage clamp investigations found the exact pH sensitivity (pKa = 7.1), open probability (high) and conductance of ~25 pS.[5] In 2007 the channel was found to interact with the Calcium-sensing receptor in human kidney, using a yeast-two-hybrid system. This co-localization was verified at the protein level using both immunofluorescence techniques and coimmunoprecipitation of Kir4.2 and the Calcium-sensing receptor.[6] Also a mutational study of Kir4.2 has demonstrated that removal of a c-terminal tyrosine increased the K+ current more than 10-fold.[7] Because the channel has a very high open probability, the authors of this last article conclude that this increase is mediated by increased trafficking of the protein to the membrane and not increased single-channel conductance. This same line of reasoning is applicable to the initial work of Derst and coworkers.[4]
Interactions
KCNJ15 has been shown to interact with Interleukin 16.[8]
See also
- Inward-rectifier potassium ion channel
References
- ↑ 1.0 1.1 "Entrez Gene: KCNJ15 potassium inwardly-rectifying channel, subfamily J, member 15". https://www.ncbi.nlm.nih.gov/sites/entrez?Db=gene&Cmd=ShowDetailView&TermToSearch=3772.
- ↑ 2.0 2.1 "Expression of a functional Kir4 family inward rectifier K+ channel from a gene cloned from mouse liver". J. Physiol. 514 (3): 639–653. 1999. doi:10.1111/j.1469-7793.1999.639ad.x. PMID 9882736.
- ↑ "Cloning and characterization of two K+ inward rectifier (Kir) 1.1 potassium channel homologs from human kidney (Kir1.2 and Kir1.3)". J. Biol. Chem. 272 (1): 586–593. 1997. doi:10.1074/jbc.272.1.586. PMID 8995301.
- ↑ 4.0 4.1 Derst C; Wischmeyer E; Preisig-Müller R et al. (1998). "A hyperprostaglandin E syndrome mutation in Kir1.1 (renal outer medullary potassium) channels reveals a crucial residue for channel function in Kir1.3 channels". J. Biol. Chem. 273 (37): 23884–23891. doi:10.1074/jbc.273.37.23884. PMID 9727001.
- ↑ "Differential pH sensitivity of Kir4.1 and Kir4.2 potassium channels and their modulation by heteropolymerisation with Kir5.1". J. Physiol. 532 (Pt 2): 359–367. 2001. doi:10.1111/j.1469-7793.2001.0359f.x. PMID 11306656.
- ↑ Huang C; Sindic A; Hill CE et al. (2007). "Interaction of the Ca2+-sensing receptor with the inwardly rectifying potassium channels Kir4.1 and Kir4.2 results in inhibition of channel function". Am. J. Physiol. Renal Physiol. 292 (3): F1073–F1081. doi:10.1152/ajprenal.00269.2006. PMID 17122384.
- ↑ "C-terminal determinants of Kir4.2 channel expression". J. Membr. Biol. 213 (3): 187–193. 2006. doi:10.1007/s00232-006-0058-6. PMID 17468958.
- ↑ Kurschner, C; Yuzaki, M (Sep 1999). "Neuronal interleukin-16 (NIL-16): a dual function PDZ domain protein". J. Neurosci. 19 (18): 7770–80. doi:10.1523/JNEUROSCI.19-18-07770.1999. PMID 10479680.
This article incorporates text from the United States National Library of Medicine, which is in the public domain.
![]() | Original source: https://en.wikipedia.org/wiki/KCNJ15.
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