STRUCTURE AND EXPRESSION OF THE HUMAN NA,K-ATPASE BETA-2-SUBUNIT GENE

We cloned and characterized the human Na,K-ATPase beta 2-subunit gene. The gene encompasses over 8 kb at chromosome 17 in the human genome a nd is composed of seven exons. Primer extension analysis identified a major transcription initiation site 529 bases upstream of the translat ion start site. The 5'-flanking region of the gene harbors a potential TATA sequence, located 94 bases upstream of the transcription initiat ion site and a number of potential promoter and regulatory elements, a mong them a Sp1 site, at position -120. A functional Sp1 site has also been found in the rat Na,K-ATPase beta 2-subunit gene (Kawakami, K., Watanabe, Y., Araki, M., Nagano, K., 1993). Spl binds to the adhesion molecule on glia regulatory element that functions as a positive trans cription regulatory element in astrocytes. (J. Neurosci. Res. 35, 138- 146). Putative AATAAA and TG sequences were found at positions 7018 an d 7068, respectively. These signals delimit the origin of the the poly (A) tail and mark the end of the sequence that completes the 3'-UT dow nstream sequence of the human cDNA. An Alu repetitive sequence is loca ted between positions 5961 and 6274. The gene is expressed as a single mRNA species, of 3.36 kb, which is present in cerebrum, cerebellum, k idney and heart, being more abundant in neural tissues. Structural ana lyses of this and other of the P-type ATPase beta subunit genes reveal that they evolved from a common ancestor. (C) 1998 Elsevier Science B .V.