|Name:||potassium inwardly-rectifying channel, subfamily J, member 13|
|PubMed (9878260):|| Derst C, Doring F, Preisig-Muller R, Daut J, Karschin A, Jeck N, Weber S,Engel H, Grzeschik KH. Partial gene structure and assignment to chromosome 2q37 of the human inwardlyrectifying K+ channel (Kir7.1) gene (KCNJ13).Genomics. 1998 Dec 15;54(3):560-3. PMID: 9878260 [PubMed - indexed for MEDLINE]|
The novel weakly inward rectifying potassium channel Kir7.1 is a low-conductance channel that is predominantly expressed in epithelial cells. Here we describe a partial genomic characterization and the chromosomal assignment of the human Kir7.1 gene (KCNJ13). Analysis of the genomic structure using a PCR-based approach revealed a single 2088-bp intron in the coding region of KCNJ13. PCR analysis of monochromosomal and radiation hybrid panels assigns KCNJ13 to band 2q37 between markers D2S331 and D2S345. In addition, a single nucleotide polymorphism (C524-->T), leading to an exchange of a Thr with an Ile residue at amino acid position 175, was found.
|PubMed (9620703):|| Krapivinsky G, Medina I, Eng L, Krapivinsky L, Yang Y, Clapham DE. A novel inward rectifier K+ channel with unique pore properties.Neuron. 1998 May;20(5):995-1005. PMID: 9620703 [PubMed - indexed for MEDLINE]|
We have cloned a novel K+-selective, inward rectifier channel that is widely expressed in brain but is especially abundant in the Purkinje cell layer of the cerebellum and pyramidal cells of the hippocampus. It is also present in a wide array of tissues, including kidney and intestine. The channel is only 38% identical to its closest relative, Kir1.3 (Kir1-ATP-regulated inward rectifier K+ [ROMK] family) and displays none of the functional properties unique to the ROMK class. Kir7.1 has several unique features, including a very low estimated single channel conductance (approximately 50 fS), low sensitivity to block by external Ba2+ and Cs+, and no dependence of its inward rectification properties on the internal blocking particle Mg2+. The unusual pore properties of Kir7.1 seem to be explained by amino acids in the pore sequence that differ from corresponding conserved residues in all other Kir channel proteins. Replacement of one of these amino acids (Met-125) with the Arg absolutely conserved in all other Kir channels dramatically increases its single channel conductance and Ba2+ sensitivity. This channel would provide a steady background K+ current to help set the membrane potential in cells in which it is expressed. We propose that the novel channel be assigned to a new Kir subfamily, Kir7.1.
>O60928|IRK13_HUMAN Inward rectifier potassium channel 13 - Homo sapiens (Human). MDSSNCKVIAPLLSQRYRRMVTKDGHSTLQMDGAQRGLAYLRDAWGILMDMRWRWMMLVFSASFVVHWLVFAVLWYVLAE MNGDLELDHDAPPENHTICVKYITSFTAAFSFSLETQLTIGYGTMFPSGDCPSAIALLAIQMLLGLMLEAFITGAFVAKI ARPKNRAFSIRFTDTAVVAHMDGKPNLIFQVANTRPSPLTSVRVSAVLYQERENGKLYQTSVDFHLDGISSDECPFFIFP LTYYHSITPSSPLATLLQHENPSHFELVVFLSAMQEGTGEICQRRTSYLPSEIMLHHCFASLLTRGSKGEYQIKMENFDK TVPEFPTPLVSKSPNRTDLDIHINGQSIDNFQISETGLTE