Genomic organization of the human FXYD2 gene encoding the gamma subunit of the Na,K-ATPase.
Although the gamma subunit of the Na,K-ATPase has only 66 or 68 amino acids, its human gene (FXYD2) was found to span 9.2 kb and have seven exons, including two alternatively spliced exons encoding different N-termini. Two candidate promoters with consensus sites for transcription factors Sp1, AP-1, and AP-2 are present, consistent with independent transcription of the splice variants. Multiple ESTs support the transcriptional competence of the identified gene elements. In the FXYD2 gene, there are two closely spaced polyadenylation signals, and both are used. A proposed third splice variant encoding a 31-residue N-terminal extension was not found in the gene, nor was the predicted larger protein found in human kidney Na,K-ATPase. Instead, evidence was found for the origin of the larger cDNA clone in homologous recombination with unrelated DNA from chromosome 2. FXYD2 is on chromosome 11q23 close to a site of tumorigenic chromosomal translocations, and has a number of repeat elements.
Sweadner
K J
KJ
Neuroscience Center, Massachusetts General Hospital, 149 13th Street, Charlestown, Massachusetts 02129, USA. sweadner@helix.mgh.harvard.edu
Wetzel
R K
RK
Arystarkhova
E
E
D017398:Alternative Splicing; D000595:Amino Acid Sequence; D005091:Exons; D006801:Humans; D007438:Introns; D008969:Molecular Sequence Data; D011401:Promoter Regions, Genetic; D000254:Sodium-Potassium-Exchanging ATPase / Q000235:genetics*; D014158:Transcription, Genetic
C416502:FXYD2 protein, human; D000254:Sodium-Potassium-Exchanging ATPase