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Gene and Protein Information  |
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| Species | TM | P Loops | AA | Chromosomal Location | Gene Symbol | Gene Name | Reference |
| Human | 2 | 1 | 375 | 21q22.13-q22.2 | KCNJ15 | potassium inwardly rectifying channel subfamily J member 15 | 9 |
| Mouse | 2 | 1 | 375 | 16 55.86 cM | Kcnj15 | potassium inwardly-rectifying channel, subfamily J, member 15 | 7 |
| Rat | 2 | 1 | 405 | 11q11 | Kcnj15 | potassium inwardly-rectifying channel, subfamily J, member 15 | 2 |
| Previous and Unofficial Names |
| potassium inwardly rectifying channel subfamily J member 15 | ATP-sensitive inward rectifier potassium channel 15 | inward rectifier K(+) channel Kir4.2 | IRKK | Kir1.3 | potassium channel, inwardly rectifying subfamily J, member 15 | potassium inwardly-rectifying channel | potassium voltage-gated channel subfamily J member 15 |
| Database Links |
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| Alphafold | Q99712 (Hs), O88932 (Mm), Q91ZF1 (Rn) |
| CATH/Gene3D | 2.60.40.1400 |
| Ensembl Gene | ENSG00000157551 (Hs), ENSMUSG00000062609 (Mm), ENSRNOG00000062944 (Rn) |
| Entrez Gene | 3772 (Hs), 16516 (Mm), 170847 (Rn) |
| Human Protein Atlas | ENSG00000157551 (Hs) |
| KEGG Gene | hsa:3772 (Hs), mmu:16516 (Mm), rno:170847 (Rn) |
| OMIM | 602106 (Hs) |
| Pharos | Q99712 (Hs) |
| RefSeq Nucleotide | NM_170736 (Hs), NM_001039056 (Mm), NM_001039057 (Mm), NM_133321 (Rn) |
| RefSeq Protein | NP_733932 (Hs), NP_001034146 (Mm), NP_001034145 (Mm), NP_579855 (Rn) |
| UniProtKB | Q99712 (Hs), O88932 (Mm), Q91ZF1 (Rn) |
| Wikipedia | KCNJ15 (Hs) |
| Associated Proteins |
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| Functional Characteristics |
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| Inward-rectifier current | |
| Ion Selectivity and Conductance |
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| Ion Selectivity and Conductance Comments | ||||||
| A functional channel is also formed by a Kir4.2/5.1 heteromer (K+, 54.2pS, [8]). |
| Voltage Dependence Comments |
| Kir4.2 forms channels that display moderate rectification: in low (2 mM) K+, currents are essentially ohmic below 0 mV, while in isomolar K+ rectification is strong, with little outward current above 0 mV [7]. |
Download all structure-activity data for this target as a CSV file 
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| Activator Comments | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| In excised patches channels are constitutively active [8]. In Xenopus oocytes prolonged exposure to elevated extracellular K+ causes slow activation of whole cell current by an unknown mechanism [7]. | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||
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| Kir4.2/5.1 heteromers also form functional channels that are pH sensitive (pEC50=7.64, [8]). Endogenous inhibitors intracellular Mg2+ and polyamines (spermine4+, spermidine3+, putrescine2+), although voltage-dependence and sensitivity are not as strong as for Kir2 channels. | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||
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| Tissue Distribution
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| Functional Assays
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| Clinically-Relevant Mutations and Pathophysiology
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| Biologically Significant Variants
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| General Comments |
| Mouse and rat Kir4.2 channel activity has been successfully studied in heterologous expression systems, while human Kir4.2 has not. Channels that may be comprised of human Kir4.2 have been recorded in Calu-3 cells, a model for human airway gland serous cells [12]. Proteins CIPP and CaR, reported as auxiliary subunits, were identified in yeast 2 hybrid screens [3-4]. No evidence of their interactions in native tissue has been reported to date. Likewise, interactions between Kir5.1 and Kir4.2 have been demonstrated electrophysiologically in heterologous expression systems [7-8], but interaction of these proteins in native tissue has not been demonstrated. |
1. Edvinsson JM, Shah AJ, Palmer LG. (2011) Potassium-dependent activation of Kir4.2 K⁺ channels. J Physiol (Lond.), 589 (Pt 24): 5949-63. [PMID:22025665]
2. Hill CE, Briggs MM, Liu J, Magtanong L. (2002) Cloning, expression, and localization of a rat hepatocyte inwardly rectifying potassium channel. Am J Physiol Gastrointest Liver Physiol, 282 (2): G233-40. [PMID:11804844]
3. Huang C, Sindic A, Hill CE, Hujer KM, Chan KW, Sassen M, Wu Z, Kurachi Y, Nielsen S, Romero MF 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): F1073-81. [PMID:17122384]
4. Kurschner C, Mermelstein PG, Holden WT, Surmeier DJ. (1998) CIPP, a novel multivalent PDZ domain protein, selectively interacts with Kir4.0 family members, NMDA receptor subunits, neurexins, and neuroligins. Mol Cell Neurosci, 11 (3): 161-72. [PMID:9647694]
5. Ohira M, Seki N, Nagase T, Suzuki E, Nomura N, Ohara O, Hattori M, Sakaki Y, Eki T, Murakami Y, Saito T, Ichikawa H, Ohki M. (1997) Gene identification in 1.6-Mb region of the Down syndrome region on chromosome 21. Genome Res, 7 (1): 47-58. [PMID:9037601]
6. Okamoto K, Iwasaki N, Doi K, Noiri E, Iwamoto Y, Uchigata Y, Fujita T, Tokunaga K. (2012) Inhibition of glucose-stimulated insulin secretion by KCNJ15, a newly identified susceptibility gene for type 2 diabetes. Diabetes, 61 (7): 1734-41. [PMID:22566534]
7. Pearson WL, Dourado M, Schreiber M, Salkoff L, Nichols CG. (1999) Expression of a functional Kir4 family inward rectifier K+ channel from a gene cloned from mouse liver. J Physiol (Lond.), 514 ( Pt 3): 639-53. [PMID:9882736]
8. Pessia M, Imbrici P, D'Adamo MC, Salvatore L, Tucker SJ. (2001) Differential pH sensitivity of Kir4.1 and Kir4.2 potassium channels and their modulation by heteropolymerisation with Kir5.1. J Physiol (Lond.), 532 (Pt 2): 359-67. [PMID:11306656]
9. Shuck ME, Piser TM, Bock JH, Slightom JL, Lee KS, Bienkowski MJ. (1997) 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): 586-93. [PMID:8995301]
10. Sindic A, Huang C, Chen AP, Ding Y, Miller-Little WA, Che D, Romero MF, Miller RT. (2009) MUPP1 complexes renal K+ channels to alter cell surface expression and whole cell currents. Am J Physiol Renal Physiol, 297 (1): F36-45. [PMID:19420109]
11. Thiery E, Gosset P, Damotte D, Delezoide AL, de Saint-Sauveur N, Vayssettes C, Créau N. (2000) Developmentally regulated expression of the murine ortholog of the potassium channel KIR4.2 (KCNJ15). Mech Dev, 95 (1-2): 313-6. [PMID:10906485]
12. Wu JV, Krouse ME, Rustagi A, Joo NS, Wine JJ. (2004) An inwardly rectifying potassium channel in apical membrane of Calu-3 cells. J Biol Chem, 279 (45): 46558-65. [PMID:15328350]
