title: The divergent orphan nuclear receptor ODR-7 regulates olfactory neuron gene expression via multiple mechanisms in Caenorhabditis elegans.
abstract: Nuclear receptors regulate numerous critical biological processes. The C. elegans genome is predicted to encode approximately 270 nuclear receptors of which >250 are unique to nematodes. ODR-7 is the only member of this large divergent family whose functions have been defined genetically. ODR-7 is expressed in the AWA olfactory neurons and specifies AWA sensory identity by promoting the expression of AWA-specific signaling genes and repressing the expression of an AWC-specific olfactory receptor gene. To elucidate the molecular mechanisms of action of a divergent nuclear receptor, we have identified residues and domains required for different aspects of ODR-7 function in vivo. ODR-7 utilizes an unexpected diversity of mechanisms to regulate the expression of different sets of target genes. Moreover, these mechanisms are distinct in normal and heterologous cellular contexts. The odr-7 ortholog in the closely related nematode C. briggsae can fully substitute for all ODR-7-mediated functions, indicating conservation of function across 25-120 million years of divergence.
authors.affiliation: Department of Biology and Volen Center for Complex Systems, Brandeis University, Waltham, Massachusetts 02454, USA.
authors.forename: Marc E
authors.initials: ME
authors.lastname: Colosimo
authors.forename: Susan
authors.initials: S
authors.lastname: Tran
authors.forename: Piali
authors.initials: P
authors.lastname: Sengupta
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D030801:Animals, Genetically Modified; D017173:Caenorhabditis elegans / Q000235:genetics* / Q000378:metabolism; D029742:Caenorhabditis elegans Proteins / Q000502:physiology*; D017124:Conserved Sequence; D018509:DNA, Helminth / Q000235:genetics / Q000378:metabolism; D005786:Gene Expression Regulation; D017238:Genes, Helminth; D014644:Genetic Variation; D020928:Mitogen-Activated Protein Kinases / Q000378:metabolism; D008969:Molecular Sequence Data; D009154:Mutation; D009419:Nerve Tissue Proteins / Q000502:physiology*; D009474:Neurons / Q000378:metabolism*; D009832:Olfactory Nerve / Q000166:cytology*; D010641:Phenotype; D017434:Protein Structure, Tertiary; D018035:Receptors, Odorant / Q000502:physiology*; D017386:Sequence Homology, Amino Acid; D015398:Signal Transduction
chemical_list: D029742:Caenorhabditis elegans Proteins; D018509:DNA, Helminth; D009419:Nerve Tissue Proteins; D018035:Receptors, Odorant; C091156:odr-7 protein, C elegans; D020928:Mitogen-Activated Protein Kinases