Calcitonin Gene Related Peptide Receptor Component Protein (CRCP)

CRCP encodes a membrane protein that functions as part of a receptor complex for a small neuropeptide that increases intracellular cAMP levels. Alternate transcriptional splice variants, encoding different isoforms, have been characterized.The deduced 148-amino acid human protein is 88% homologous to the guinea pig protein. Northern blot analysis revealed expression of a major 3.1-kb and a minor 7.4-kb transcript, with highest levels in testis, followed by prostate, ovary, small intestine, and spleen, with little expression in thymus, colon, and peripheral blood mononuclear cells. Immunoblot analysis indicated that CGRPRCP is expressed as a 20-kD protein. Immunohistochemical analysis demonstrated strong expression in acrosomes of murine but not human spermatozoa.