THE MYOMODULIN-RELATED NEUROPEPTIDES - CHARACTERIZATION OF A GENE ENCODING A FAMILY OF PEPTIDE COTRANSMITTERS IN APLYSIA

The myomodulin-related peptides comprise a family of cotransmitters th at modulate neuromuscular signaling in the feeding system of Aplysia. In this study, cDNA clones encoding a myomodulin precursor polypeptide were isolated and characterized. This precursor contains seven differ ent myomodulin-related peptides, one of which, myomodulin A, is presen t in 10 contiguous copies. The sequence of a myomodulin genomic clone indicates that all of these myomodulin-related peptides are encoded on a single exon. The myomodulin gene is expressed in a tissue-specific manner and myomodulin mRNA is localized to specific neurons in the Apl ysia CNS. The presence of multiple related neuropeptides can greatly i ncrease the range and precision of signaling at synapses where they ac t as modulator cotransmitters.