The divergent orphan nuclear receptor ODR-7 regulates olfactory neuron gene expression via multiple mechanisms in Caenorhabditis elegans.
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.
Colosimo
Marc E
ME
Department of Biology and Volen Center for Complex Systems, Brandeis University, Waltham, Massachusetts 02454, USA.
Tran
Susan
S
Sengupta
Piali
P
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
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