title: R15 alpha 1 and R 15 alpha 2 peptides from Aplysia: comparison of bioactivity, distribution, and function of two peptides generated by alternative splicing.
abstract: The mRNA precursor encoded by the R15 gene is alternatively spliced in different neurons to form two related variants, R15-1 and R15-2 mRNA. One of the peptides encoded by the R15-2 mRNA, the R15 alpha 1 peptide, is expressed in the endogenously bursting neuron R15 and mediates some of its central and peripheral synaptic actions. In this study we found that the R15 alpha 2 peptide, which is encoded by the R15-1 mRNA, is synthesized in other neurons in the abdominal ganglion and is also bioactive. The R15 alpha 1 and R15 alpha 2 peptides were found to exert many similar actions on the cardiovascular, digestive, respiratory, and reproductive systems. However, the differences between many of the pharmacological effects of the R15 alpha 1 and R15 alpha 2 peptides indicate that alternative splicing in this system results in two functionally different peptides. Widespread immunoreactivity was found for an antibody directed against the R15 alpha 2 peptide, both in the central nervous system and the periphery. But because of the shared sequence with the R15 alpha 1 peptide, the antibody cross-reacts with the R15 alpha 1 peptide. To distinguish immunocytochemically between the two peptides, we also raised a second antibody that recognizes only the R15 alpha 1 peptide. This antibody labeled the cell body of only one neuron in the central nervous system, R15, although widespread immunoreactivity was found in axons and varicosities in the periphery.
authors.affiliation: Department of Physiology and Cellular Biophysics, Columbia University, New York, New York 10032.
authors.forename: A
authors.initials: A
authors.lastname: Alevizos
authors.forename: D
authors.initials: D
authors.lastname: Karagogeos
authors.forename: K R
authors.initials: KR
authors.lastname: Weiss
authors.forename: L
authors.initials: L
authors.lastname: Buck
authors.forename: J
authors.initials: J
authors.lastname: Koester
mesh_terms: D000818:Animals; D000911:Antibodies, Monoclonal; D001048:Aplysia / Q000378:metabolism*; D005724:Ganglia / Q000378:metabolism; D007150:Immunohistochemistry; D008715:Methionine / Q000378:metabolism; D009479:Neuropeptides / Q000276:immunology / Q000378:metabolism* / Q000502:physiology; D009693:Nucleic Acid Hybridization; D012326:RNA Splicing
chemical_list: D000911:Antibodies, Monoclonal; D009479:Neuropeptides; C068722:R15alpha1 protein, Aplysia; D008715:Methionine