The present invention is directed to polynucleotides, polypeptides and peptide fragments thereof, and uses thereof for a novel cDNA sequence which has homology to motilin. Tissue distribution of the mRNA for the novel polypeptide is specific to the stomach, small intestine and pancreas. The present invention further includes agonists, antagonists, antibodies, host cells expressing the cDNA encoding the novel motilin homologs and methods for increasing gastric motility using the novel molecules.