title: Requirement for Drosophila SNMP1 for rapid activation and termination of pheromone-induced activity.
abstract: Pheromones are used for conspecific communication by many animals. In Drosophila, the volatile male-specific pheromone 11-cis vaccenyl acetate (cVA) supplies an important signal for gender recognition. Sensing of cVA by the olfactory system depends on multiple components, including an olfactory receptor (OR67d), the co-receptor ORCO, and an odorant binding protein (LUSH). In addition, a CD36 related protein, sensory neuron membrane protein 1 (SNMP1) is also involved in cVA detection. Loss of SNMP1 has been reported to eliminate cVA responsiveness, and to greatly increase spontaneous activity of OR67d-expressing olfactory receptor neurons (ORNs). Here, we found the snmp1(1) mutation did not abolish cVA responsiveness or cause high spontaneous activity. The cVA responses in snmp1 mutants displayed a delayed onset, and took longer to reach peak activity than wild-type. Most strikingly, loss of SNMP1 caused a dramatic delay in signal termination. The profound impairment in signal inactivation accounted for the previously reported "spontaneous activity," which represented continuous activation following transient exposure to environmental cVA. We introduced the silk moth receptor (BmOR1) in OR67d ORNs of snmp1(1) flies and found that the ORNs showed slow activation and deactivation kinetics in response to the BmOR1 ligand (bombykol). We expressed the bombykol receptor complex in Xenopus oocytes in the presence or absence of the silk moth SNMP1 (BmSNMP) and found that addition of BmSNMP accelerated receptor activation and deactivation. Our results thus clarify SNMP1 as an important player required for the rapid kinetics of the pheromone response in insects.
authors.affiliation: Department of Biological Chemistry, The Johns Hopkins University School of Medicine, Baltimore, Maryland, United States of America.
authors.forename: Zhengzheng
authors.initials: Z
authors.lastname: Li
authors.affiliation: Department of Biological Chemistry, The Johns Hopkins University School of Medicine, Baltimore, Maryland, United States of America; Neuroscience Research Institute and Department of Molecular, Cellular and Developmental Biology, University of California, Santa Barbara, Santa Barbara, California.
authors.forename: Jinfei D
authors.initials: JD
authors.lastname: Ni
authors.affiliation: Neuroscience Research Institute and Department of Molecular, Cellular and Developmental Biology, University of California, Santa Barbara, Santa Barbara, California.
authors.forename: Jia
authors.initials: J
authors.lastname: Huang
authors.affiliation: Neuroscience Research Institute and Department of Molecular, Cellular and Developmental Biology, University of California, Santa Barbara, Santa Barbara, California.
authors.forename: Craig
authors.initials: C
authors.lastname: Montell
mesh_terms: D000200:Action Potentials / Q000187:drug effects; D000818:Animals; D001522:Behavior, Animal / Q000187:drug effects; D004330:Drosophila / Q000502:physiology*; D005260:Female; D008297:Male; D008565:Membrane Proteins / Q000235:genetics / Q000378:metabolism*; D009154:Mutation; D009419:Nerve Tissue Proteins / Q000235:genetics / Q000378:metabolism*; D009829:Oleic Acids / Q000008:administration & dosage; D018034:Olfactory Receptor Neurons / Q000187:drug effects / Q000502:physiology; D010675:Pheromones / Q000008:administration & dosage / Q000378:metabolism*
chemical_list: C518845:11-cis-vaccenyl acetate; D008565:Membrane Proteins; D009419:Nerve Tissue Proteins; D009829:Oleic Acids; D010675:Pheromones; C106308:sensory neuron membrane protein 1