Identification and characterization of a G protein-coupled receptor for the neuropeptide proctolin in Drosophilamelanogaster.
Proctolin is a bioactive neuropeptide that modulates interneuronal and neuromuscular synaptic transmission in a wide variety of arthropods. We present several lines of evidence to propose that the orphan G protein-coupled receptor CG6986 of Drosophila is a proctolin receptor. When expressed in mammalian cells, CG6986 confers second messenger activation after proctolin application, with an EC(50) of 0.3 nM. In competition-based studies, the CG6986 receptor binds proctolin with high affinity (IC(50) = 4 nM). By microarray analysis, CG6986 transcript is consistently detected in head mRNA of different genotypes, and under different environmental conditions. By blot analysis, anti-CG6986 antibodies detect a band in tissue homogenates similar to the predicted size of the protein. Proctolin receptor immunosignals are found in the hindgut, heart, and in distinct neuronal populations of the CNS; such patterns correlate with previous demonstrations of proctolin biological activity, and in several instances, with areas of proctolin peptide immunosignals. The identification of a bona fide proctolin receptor provides the basis for a mechanistic analysis of this critical synaptic modulator.
Johnson
Erik C
EC
Department of Anatomy and Neurobiology, Washington University School of Medicine, St. Louis, MO 63110, USA.
Garczynski
Stephen F
SF
Park
Dongkook
D
Crim
Joe W
JW
Nassel
Dick R
DR
Taghert
Paul H
PH
D000818:Animals; D001665:Binding Sites; D002460:Cell Line; D003001:Cloning, Molecular; D029721:Drosophila Proteins / Q000235:genetics* / Q000378:metabolism; D004331:Drosophila melanogaster; D019204:GTP-Binding Proteins / Q000378:metabolism*; D006801:Humans; D007700:Kinetics; D009479:Neuropeptides; D009842:Oligopeptides / Q000378:metabolism*; D009928:Organ Specificity; D018000:Receptors, Peptide / Q000235:genetics* / Q000378:metabolism; D011994:Recombinant Proteins / Q000378:metabolism; D015398:Signal Transduction; D014162:Transfection
D029721:Drosophila Proteins; D009479:Neuropeptides; D009842:Oligopeptides; C474930:Proc-R protein, Drosophila; D018000:Receptors, Peptide; D011994:Recombinant Proteins; C011536:proctolin; D019204:GTP-Binding Proteins