Cloning and sequence analysis of a cDNA encoding rat preprocholecystokinin

摘要: Abstract Poly(A) RNA was isolated from a rat medullary thyroid carcinoma that exhibited high levels of immunoreactive cholecystokinin (CCK). Double-stranded cDNA synthesized the poly(A) and inserted into Pst I site pBR322. Bacterial colonies containing CCK were identified using hybridization probe d(T-C-C-A-T-C-C-A-N-C-C-C-A-T-G-T-A-G-T-C). The sequence deduced known amino acid porcine CCK-8, Asp-Tyr-Met-Gly-Trp-Met-Asp-Phe-NH2. nucleotide complementary to mRNA preprocholecystokinin determined. contains 33 nucleotides in 5'-noncoding region, 199 3'-noncoding 345 coding for precursor CCK, which is 115 acids (Mr, 12,826). Examination gene revealed suggested transcriptional control analogous "TATA" located upstream proposed start site. CCK-39 flanked by both amino-terminal carboxyl-terminal extensions. Analysis showed it approximately equal 750 long. brain intestine appeared be identical size carcinoma.