title: A specific subset of transient receptor potential vanilloid-type channel subunits in Caenorhabditis elegans endocrine cells function as mixed heteromers to promote neurotransmitter release.
abstract: Transient receptor potential (TRP) channel subunits form homotetramers that function in sensory transduction. Heteromeric channels also form, but their physiological subunit compositions and functions are largely unknown. We found a dominant-negative mutant of the C. elegans TRPV (vanilloid-type) subunit OCR-2 that apparently incorporates into and inactivates OCR-2 homomers as well as heteromers with the TRPV subunits OCR-1 and -4, resulting in a premature egg-laying defect. This defect is reproduced by knocking out all three OCR genes, but not by any single knockout. Thus a mixture of redundant heteromeric channels prevents premature egg laying. These channels, as well as the G-protein G alpha(o), function in neuroendocrine cells to promote release of neurotransmitters that block egg laying until eggs filling the uterus deform the neuroendocrine cells. The TRPV channel OSM-9, previously suggested to be an obligate heteromeric partner of OCR-2 in sensory neurons, is expressed in the neuroendocrine cells but has no detectable role in egg laying. Our results identify a specific set of heteromeric TRPV channels that redundantly regulate neuroendocrine function and show that a subunit combination that functions in sensory neurons is also present in neuroendocrine cells but has no detectable function in these cells.
authors.affiliation: Department of Molecular Biophysics and Biochemistry, Yale University, New Haven, Connecticut 06520, USA.
authors.forename: Antony M
authors.initials: AM
authors.lastname: Jose
authors.forename: I Amy
authors.initials: IA
authors.lastname: Bany
authors.forename: Daniel L
authors.initials: DL
authors.lastname: Chase
authors.forename: Michael R
authors.initials: MR
authors.lastname: Koelle
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D030801:Animals, Genetically Modified; D001692:Biological Transport; D017173:Caenorhabditis elegans / Q000235:genetics / Q000254:growth & development / Q000378:metabolism*; D029742:Caenorhabditis elegans Proteins / Q000235:genetics / Q000378:metabolism; D004702:Endocrine Glands / Q000166:cytology / Q000378:metabolism*; D005260:Female; D007473:Ion Channels / Q000235:genetics / Q000378:metabolism; D008969:Molecular Sequence Data; D009419:Nerve Tissue Proteins / Q000235:genetics / Q000378:metabolism; D009490:Neurosecretory Systems / Q000166:cytology / Q000378:metabolism*; D010058:Oviposition / Q000502:physiology*; D017386:Sequence Homology, Amino Acid; D050916:TRPV Cation Channels / Q000235:genetics / Q000378:metabolism*
chemical_list: D029742:Caenorhabditis elegans Proteins; D007473:Ion Channels; D009419:Nerve Tissue Proteins; C464589:OCR-1 protein, C elegans; C464590:OCR-2 protein, C elegans; D050916:TRPV Cation Channels