Molecular cloning and analysis of full-length cDNAs cognate to a rat gene under multihormonal control.

Gene 33 is a multihormonally regulated rat gene whose transcription is rapidly and markedly enhanced by glucocorticoids, insulin, or cAMP. A cDNA clone (p216) containing a nearly full-length DNA complementary to the mRNA of this gene was isolated from a cDNA library and sequenced. The cDNA represents the entire mRNA transcript, except for three bases at the 5' terminus. The message is 2970 nucleotides long and can encode a protein of 459 amino acids with a molecular mass of 49,919 Da. The deduced amino acid sequence is rich in proline and serine but bears little homology to any known sequences. The 5' untranslated region, rich in G + C, is 270 nucleotides long and contains two apparently nonfunctional AUG initiator codons. The 3' untranslated sequence, rich in A + U, is 1323 nucleotides long and has a polyadenylation signal 13 bases upstream of the poly(A) tract. Two mRNA transcripts of the gene, which appear to be the consequence of alternative usage of splice sites, have been identified. The less abundant mRNA is truncated by 228 nucleotides in the protein coding region. The reading frame is maintained and this mRNA can code for a protein of 383 amino acids with a calculated molecular mass of 42,204 Da.