MOLECULAR-CLONING, UPSTREAM SEQUENCE AND PROMOTER STUDIES OF THE HUMAN GENE FOR THE REGULATORY SUBUNIT RII-ALPHA OF CAMP-DEPENDENT PROTEIN-KINASE

The gene for the regulatory subunit RII alpha of cAMP-dependent protei n kinase is highly regulated during spermatogenesis and a strong signa l from a distinct short mRNA form is observed postmeiotically during s permatid elongation. This report presents the isolation and characteri zation of the 5'-flanking region (1.2 kb) and exon I of the human RII alpha gene. S1 nuclease mapping and primer extension experiments revea led the presence of a major transcriptional start site located 208 nuc leotides upstream of start for translation. The 5'-flanking region of the RII alpha gene did not contain a TATA box and was highly G/C-rich. A basal promoter directing high levels of chloramphenicol acetyl tran sferase (CAT) activity was identified in the 5'-flanking sequence. Sev eral potential binding sites for transcription factors were identified in this region, which may be responsible for the germ cell-specific r egulation of this gene. We have previously reported that the human tes tis RII alpha cDNA contains a region (amino acids 45-75) with little o r no homology to the corresponding rat skeletal muscle cDNA (Oyen, O., Myklebust, F., Scott, J.D., Cadd. G.G., McKnight, G.S., Hansson, V. a nd Jahnsen, T. (1990) Biol. Reprod. 43, 46-54). We examined whether th is difference could arise due to organ-specific splice mechanisms or r epresented a species difference. We show that the low homology region of the human RII alpha cDNA resides entirely within exon 1, and does n ot originate from a tissue-specific alternate splicing of this distinc t region.