title: Cell-Autonomous and Non-Cell-Autonomous Regulation of a Feeding State-Dependent Chemoreceptor Gene via MEF-2 and bHLH Transcription Factors.
abstract: Food and feeding-state dependent changes in chemoreceptor gene expression may allow Caenorhabditis elegans to modify their chemosensory behavior, but the mechanisms essential for these expression changes remain poorly characterized. We had previously shown that expression of a feeding state-dependent chemoreceptor gene, srh-234, in the ADL sensory neuron of C. elegans is regulated via the MEF-2 transcription factor. Here, we show that MEF-2 acts together with basic helix-loop-helix (bHLH) transcription factors to regulate srh-234 expression as a function of feeding state. We identify a cis-regulatory MEF2 binding site that is necessary and sufficient for the starvation-induced down regulation of srh-234 expression, while an E-box site known to bind bHLH factors is required to drive srh-234 expression in ADL. We show that HLH-2 (E/Daughterless), HLH-3 and HLH-4 (Achaete-scute homologs) act in ADL neurons to regulate srh-234 expression. We further demonstrate that the expression levels of srh-234 in ADL neurons are regulated remotely by MXL-3 (Max-like 3 homolog) and HLH-30 (TFEB ortholog) acting in the intestine, which is dependent on insulin signaling functioning specifically in ADL neurons. We also show that this intestine-to-neuron feeding-state regulation of srh-234 involves a subset of insulin-like peptides. These results combined suggest that chemoreceptor gene expression is regulated by both cell-autonomous and non-cell-autonomous transcriptional mechanisms mediated by MEF2 and bHLH factors, which may allow animals to fine-tune their chemosensory responses in response to changes in their feeding state.
authors.affiliation: Department of Biology, University of Nevada, Reno, Reno, Nevada, United States of America.
authors.forename: Matthew
authors.initials: M
authors.lastname: Gruner
authors.affiliation: Department of Biology, University of Nevada, Reno, Reno, Nevada, United States of America.
authors.forename: Jeremy
authors.initials: J
authors.lastname: Grubbs
authors.affiliation: Department of Biology, University of Nevada, Reno, Reno, Nevada, United States of America.
authors.forename: Aja
authors.identifier: 0000-0001-8905-4862
authors.initials: A
authors.lastname: McDonagh
authors.affiliation: Department of Biology, University of Nevada, Reno, Reno, Nevada, United States of America.
authors.forename: Dominic
authors.identifier: 0000-0002-6835-6869
authors.initials: D
authors.lastname: Valdes
authors.affiliation: Department of Biology, University of Nevada, Reno, Reno, Nevada, United States of America.
authors.forename: Ari
authors.initials: A
authors.lastname: Winbush
authors.affiliation: Department of Biology, University of Nevada, Reno, Reno, Nevada, United States of America.
authors.forename: Alexander M
authors.initials: AM
authors.lastname: van der Linden
mesh_terms: D000818:Animals; D030801:Animals, Genetically Modified; D051792:Basic Helix-Loop-Helix Proteins / Q000096:biosynthesis / Q000235:genetics*; D001665:Binding Sites; D017173:Caenorhabditis elegans / Q000235:genetics / Q000254:growth & development; D029742:Caenorhabditis elegans Proteins / Q000096:biosynthesis / Q000235:genetics*; D002628:Chemoreceptor Cells / Q000378:metabolism*; D018507:Gene Expression Regulation, Developmental; D018013:Receptors, Neuropeptide / Q000096:biosynthesis / Q000235:genetics*; D018017:Receptors, Pituitary Hormone-Regulating Hormone / Q000096:biosynthesis / Q000235:genetics*; D011984:Sensory Receptor Cells / Q000378:metabolism; D015398:Signal Transduction / Q000235:genetics; D014157:Transcription Factors / Q000096:biosynthesis / Q000235:genetics*
chemical_list: D051792:Basic Helix-Loop-Helix Proteins; D029742:Caenorhabditis elegans Proteins; D018013:Receptors, Neuropeptide; D018017:Receptors, Pituitary Hormone-Regulating Hormone; D014157:Transcription Factors; C106514:HLH-2 protein, C elegans; C106515:HLH-3 protein, C elegans; C583070:MXL-3 protein, C elegans; C518291:mef-2 protein, C elegans; C048250:somatotropin releasing hormone receptor