Nucleotide sequence of a nearly full-length cDNA coding for pepsinogen of rat gastric mucosa.

A nearly full-length rat pepsinogen cDNA was isolated from a rat gastric mucosa cDNA library and its nucleotide sequence was determined. The cDNA comprises 1370 base pairs (bp), including the 5'-non-coding region (60 bp), the coding nucleotide sequence (1176 bp) and the 3'-non-coding region (131 bp). The predicted amino acid sequence of rat prepepsinogen (392 residues) contains a 16-residue signal sequence followed by the pepsionogen moiety of 376 residues. Rat pepsinogen has an amino acid composition characteristic of C-type pepsinogens and is much more homologous in amino acid sequence with C-type pepsinogens than A-type pepsinogens. These results indicate that the major form of rat pepsinogen can be classified as a C type pepsinogen.