Goalpha regulates olfactory adaptation by antagonizing Gqalpha-DAG signaling in Caenorhabditis elegans.
The heterotrimeric G protein G(o) is abundantly expressed in the mammalian nervous system and modulates neural activities in response to various ligands. However, G(o)'s functions in living animals are less well understood. Here, we demonstrate that GOA-1 G(o)alpha has a fundamental role in olfactory adaptation in Caenorhabditis elegans. Impairment of GOA-1 G(o)alpha function and excessive activation of EGL-30 G(q)alpha cause a defect in adaptation to AWC-sensed odorants. These pathways antagonistically modulate olfactory adaptation in AWC chemosensory neurons. Wild-type animals treated with phorbol esters and double-mutant animals of diacylglycerol (DAG) kinases, dgk-3; dgk-1, also have a defect in adaptation, suggesting that elevated DAG signals disrupt normal adaptation. Constitutively active GOA-1 can suppress the adaptation defect of dgk-3; dgk-1 double mutants, whereas it fails to suppress the adaptation defect of animals with constitutively active EGL-30, implying that GOA-1 acts upstream of EGL-30 in olfactory adaptation. Our results suggest that down-regulation of EGL-30-DAG signaling by GOA-1 underlies olfactory adaptation and plasticity of chemotaxis.
Matsuki
Masahiro
M
Molecular Genetics Research Laboratory and Graduate Program in Biophysics and Biochemistry, Graduate School of Science, University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-0033, Japan.
Kunitomo
Hirofumi
H
Iino
Yuichi
Y
D000222:Adaptation, Physiological; D000818:Animals; D017173:Caenorhabditis elegans; D029742:Caenorhabditis elegans Proteins / Q000502:physiology; D002468:Cell Physiological Phenomena; D002633:Chemotaxis; D018076:DNA, Complementary / Q000378:metabolism; D019852:Diacylglycerol Kinase / Q000378:metabolism; D004305:Dose-Response Relationship, Drug; D015536:Down-Regulation; D004926:Escherichia coli / Q000378:metabolism; D019206:GTP-Binding Protein alpha Subunits, Gi-Go / Q000378:metabolism*; D043802:GTP-Binding Protein alpha Subunits, Gq-G11 / Q000378:metabolism*; D019204:GTP-Binding Proteins / Q000378:metabolism; D009154:Mutation; D009420:Nervous System / Q000378:metabolism; D009474:Neurons / Q000378:metabolism; D009812:Odorants; D015398:Signal Transduction; D012903:Smell
D029742:Caenorhabditis elegans Proteins; D018076:DNA, Complementary; D019852:Diacylglycerol Kinase; D019204:GTP-Binding Proteins; D019206:GTP-Binding Protein alpha Subunits, Gi-Go; D043802:GTP-Binding Protein alpha Subunits, Gq-G11