A putative fourth Na+,K(+)-ATPase alpha-subunit gene is expressed in testis.
The Na+,K(+)-ATPase alpha subunit has three known isoforms, alpha 1, alpha 2 and alpha 3, each encoded by a separate gene. This study was undertaken to determine the functional status of a fourth human alpha-like gene, ATP1AL2. Partial genomic sequence analysis revealed regions exhibiting sequence similarity with exons 3-6 of the Na+,K(+)-ATPase alpha isoform genes. ATP1AL2 cDNAs spanning the coding sequence of a novel P-type ATPase alpha subunit were isolated from a rat testis library. The predicted polypeptide is 1028 amino acids long and exhibits 76-78% identity with the rat Na+,K(+)-ATPase alpha 1, alpha 2 and alpha 3 isoforms, indicating that ATP1AL2 may encode a fourth Na+,K(+)-ATPase alpha isoform. A 3.9-kb mRNA is expressed abundantly in human and rat testis.
Shamraj
O I
OI
Department of Molecular Genetics, Biochemistry and Microbiology, University of Cincinnati College of Medicine, OH 45267-0524.
Lingrel
J B
JB
D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D003001:Cloning, Molecular; D018076:DNA, Complementary / Q000235:genetics; D015870:Gene Expression; D005796:Genes; D006801:Humans; D007527:Isoenzymes / Q000235:genetics; D008297:Male; D008969:Molecular Sequence Data; D012333:RNA, Messenger / Q000235:genetics; D051381:Rats; D016415:Sequence Alignment; D017386:Sequence Homology, Amino Acid; D000254:Sodium-Potassium-Exchanging ATPase / Q000235:genetics*; D013737:Testis / Q000201:enzymology*; D014018:Tissue Distribution
D018076:DNA, Complementary; D007527:Isoenzymes; D012333:RNA, Messenger; D000254:Sodium-Potassium-Exchanging ATPase