Phylogenetic analysis of the sequences of gastrin-releasing peptide and its receptors: Biological implications

Abstract

The many biological activities of the hormone gastrin-releasing peptide (GRP), including stimulation of acid secretion and of tumour growth, are mediated by the gastrin-releasing peptide receptor (GRP-R). Here sequence comparisons are utilised to investigate the likely bioactive regions of the 125 amino acid GRP precursor and of GRP-R. Comparison of the sequences of the GRP precursor from 21 species revealed homology not only in the GRP region between amino acids 1 and 30, but also in C-terminal regions from amino acids 43 to 97. This observation is consistent with recent reports that peptides derived from the C-terminal region are biologically active. Comparison of the GRP-R sequence with t..