|Name:||ATPase, Na+/K+ transporting, beta polypeptide-like 1|
|PubMed (2559024):|| Lane LK, Shull MM, Whitmer KR, Lingrel JB. Characterization of two genes for the human Na,K-ATPase beta subunit.Genomics. 1989 Oct;5(3):445-53. PMID: 2559024 [PubMed - indexed for MEDLINE]|
A total of 29 human genomic DNA clones that hybridize with cDNAs for the sheep and rat Na,K-ATPase beta subunits have been isolated, classified by restriction endonuclease mapping and Southern blot hybridization analysis, and sequenced. One class of clones, designated ATP1BL1, represents a processed pseudogene for the beta subunit. The second class, designated ATP1B, includes 15 overlapping genomic clones and represents a functional gene for the human Na,K-ATPase beta subunit. ATP1B spans about 26.7 kb of genomic DNA and includes 24 kb of intron sequence. The complete mRNA transcript for the human beta subunit is encoded by six exons, ranging in size from 81 to 1427 bp. Primer extension and S1 nuclease protection experiments with human kidney RNA indicate the presence of two major transcription initiation sites at -510 and -201 to -191, with minor initiation sites at -268, -182 to -174, and -142. The distal initiation site at -510 is preceded by consensus sequences for CAAT and TATA boxes. The DNA sequence preceding the proximal heterogeneous initiation sites contains a CAAT box, but no TATA box. Two of the 12 GC boxes (GGCGGG and CCCGCC) located in the 5' region of ATP1B are located between this CAAT box and the proximal clusters of transcription initiation sites.
|PubMed (2842249):|| Yang-Feng TL, Schneider JW, Lindgren V, Shull MM, Benz EJ Jr, Lingrel JB,Francke U. Chromosomal localization of human Na+, K+-ATPase alpha- and beta-subunit genes.Genomics. 1988 Feb;2(2):128-38. PMID: 2842249 [PubMed - indexed for MEDLINE]|
Na+, K+-ATPase is a heterodimeric enzyme responsible for the active maintenance of sodium and potassium gradients across the plasma membrane. Recently, cDNAs for several tissue-specific isoforms of the larger catalytic alpha-subunit and the smaller beta-subunit have been cloned. We have hybridized rat brain and human kidney cDNA probes, as well as human genomic isoform-specific DNA fragments, to Southern filters containing panels of rodent X human somatic cell hybrid lines. The results obtained have allowed us to assign the loci for the ubiquitously expressed alpha-chain (ATP1A1) to human chromosome 1, region 1p21----cen, and for the alpha 2 isoform that predominates in neural and muscle tissues (ATP1A2) to chromosome 1, region cen----q32. A common PstI RFLP was detected with the ATP1A2 probe. The alpha 3 gene, which is expressed primarily in neural tissues (ATP1A3), was assigned to human chromosome 19. A fourth alpha gene of unknown function (alpha D) that was isolated by molecular cloning (ATP1AL1) was mapped to chromosome 13. Although evidence to date had suggested a single gene for the beta-subunit, we found hybridizing restriction fragments derived from two different human chromosomes. On the basis of knowledge of conserved linkage groups on human and murine chromosomes, we propose that the coding gene ATP 1B is located on the long arm of human chromosome 1 and that the sequence on human chromosome 4 (ATP 1BL1) is either a related gene or a pseudogene.