TABLE 12

Kir5.1 channels

Channel name Kir5.1
Description Inwardly rectifying potassium channel Kir5.1 subunit
Other names BIR 91
Molecular information Human (KCNJ16): 418aa, Locus ID: 3773, GenBank: AF179353, NM_018658, chr. 17q23.1-24.2
Rat (Kcnj16): 419aa, Locus ID: 29719, GenBank: X83581, AF249676, NM_053314, PMID: 7874445,1 10764726,2 chr. 10q32.1
Mouse: 418aa, Locus ID: 16517, GenBank: AB016197, NM_010604, PMID: 9806850,3 chr. 11, 71.0 centimorgans
Associated subunits Kir4.1, Kir4.24 associates with PSD-95 to form functional homomeric channels5
Functional assays Voltage-clamp in Xenopus oocytes, HEK293 cells
Current Inwardly rectifying K+ current
Conductance 54pS when coexpressed with Kir4.2(120 mM K+)4
Ion selectivity K+
Activation Not established
Inactivation Not established
Activators None
Gating inhibitors Protein kinase A phosphorylation5
Blockers Nonselective: Ba2+, Cs+; intracellular H+ for Kir5.1/Kir4.1
Radioligands None
Channel distribution Convoluted tubule cells of the kidney, pancreatic acinar and ductal cells, thyroid gland,6 Müller cells and GABAergic amacrine cells of the retina,7 spiral ligament of the cochlear lateral wall,8 spleen, adrenal gland, liver, testis,1 and regions of the brain including forebrain and olfactory astrocytes,9 brainstem nuclei; locus coeruleus, mesencephalic trigeminal nucleus, hypoglossal nucleus10 and pontine nucleus11
Physiological functions pH sensing2
Mutations and pathophysiology Not established
Pharmacological significance Not established

  • aa, amino acids; chr., chromosome; HEK, human embryonic kidney.

  • ↵1. Bond CT, Pessia M, Xia XM, Lagrutta A, Kavanaugh MP, and Adelman JP (1994) Cloning and expression of a family of inward rectifier potassium channels. Receptors Channels 2:183–191. [Erratum in Receptors Channels (1994) 2:following 350]

  • ↵2. Tucker SJ, Imbrici P, Salvatore L, D'Adamo MC, and Pessia M (2000) pH dependence of the inwardly rectifying potassium channel Kir5.1 and localization in renal tubular epithelia. J Biol Chem 275:16404-16407

  • ↵3. Mouri T, Kittaka N, HorioY, Copeland NG, Gilbert DJ, Jenkins NA, and Kurachi Y (1998) Assignment of mouse inwardly rectifying potassium channel kcnj16 to the distal region of mouse chromosome 11. Genomics 54:181-182

  • ↵4. Pessia M, Imbrici P, D'Adamo MC, Salvatore L, and Tucker SJ (2001) Differential pH sensitivity of Kir4.1 and Kir4.2 potassium channels and their modulation by heteropolymerisation with Kir5.1. J Physiol 532:359-367

  • ↵5. Tanemoto M, Fujita A, Higashi K, and Kurachi Y (2002) PSD-95 mediates formation of a functional homomeric Kir5.1 channel in the brain. Neuron 34:387-397

  • ↵6. Liu Y, McKenna E, Figueroa DJ, Blevins R, Austin CP, Bennett PB, and Swanson R (2000) The human inward rectifier K+ channel subunit Kir5.1 (KCNJ16) maps to chromosome 17q25 and is expressed in kidney and pancreas. Cytogenet Cell Genet 90:60-63

  • ↵7. Ishii M, Fujita A, Iwai K, Kusaka S, Higashi K, Inanobe A, Hibino H, and Kurachi Y (2003) Differential expression and distribution of Kir5.1 and Kir4.1 inwardly rectifying K+ channels in retina. Am J Physiol Cell Physiol 285:C260-C267

  • ↵8. Hibino H, Higashi-Shingai K, Fujita A, Iwai K, Ishii M, and Kurachi Y (2004) Expression of an inwardly rectifying K+ channel Kir5.1 in specific types of fibrocytes in the cochlear lateral wall suggests its functional importance in the establishment of endocochlear potential. Eur J Neurosci 19:76-84

  • ↵9. Hibino H, Fujita A, Iwai K, Yamada M, and Kurachi Y (2004) Differential assembly of inwardly rectifying K+ channel subunits Kir4.1 and Kir5.1 in brain astrocytes. J Biol Chem 279:44065-44073

  • ↵10. Wu J, Xu H, Shen W, and Jiang C (2004) Expression and coexpression of CO2-sensitive Kir channels in brainstem neurons of rats. J Membr Biol 197:179-191

  • ↵11. Derst C, Karschin C, Wischmeyer E, Hirsch JR, Preisig-Muller R, Rajan S, Engel H, Grzeschik K, Daut J, and Karschin A (2001) Genetic and functional linkage of Kir5.1 and Kir2.1 channel subunits. FEBS Lett 491:305-311