title: Functional coupling of a nematode chemoreceptor to the yeast pheromone response pathway.
abstract: Sequencing of the Caenorhabditis elegans genome revealed sequences encoding more than 1,000 G-protein coupled receptors, hundreds of which may respond to volatile organic ligands. To understand how the worm's simple olfactory system can sense its chemical environment there is a need to characterise a representative selection of these receptors but only very few receptors have been linked to a specific volatile ligand. We therefore set out to design a yeast expression system for assigning ligands to nematode chemoreceptors. We showed that while a model receptor ODR-10 binds to C. elegans Gα subunits ODR-3 and GPA-3 it cannot bind to yeast Gα. However, chimaeras between the nematode and yeast Gα subunits bound to both ODR-10 and the yeast Gβγ subunits. FIG2 was shown to be a superior MAP-dependent promoter for reporter expression. We replaced the endogenous Gα subunit (GPA1) of the Saccharomyces cerevisiae (ste2Δ sst2Δ far1Δ) triple mutant ("Cyb") with a Gpa1/ODR-3 chimaera and introduced ODR-10 as a model nematode GPCR. This strain showed concentration-dependent activation of the yeast MAP kinase pathway in the presence of diacetyl, the first time that the native form of a nematode chemoreceptor has been functionally expressed in yeast. This is an important step towards en masse de-orphaning of C. elegans chemoreceptors.
authors.affiliation: CSIRO Food Futures National Research Flagship & CSIRO Ecosystem Sciences, Australia, PO Box 1700, Canberra, ACT 2601, Australia.
authors.forename: Muhammad
authors.initials: M
authors.lastname: Tehseen
authors.affiliation: CSIRO Food Futures National Research Flagship & CSIRO Ecosystem Sciences, Australia, PO Box 1700, Canberra, ACT 2601, Australia.
authors.forename: Mira
authors.initials: M
authors.lastname: Dumancic
authors.affiliation: CSIRO Food Futures National Research Flagship & CSIRO Ecosystem Sciences, Australia, PO Box 1700, Canberra, ACT 2601, Australia.
authors.forename: Lyndall
authors.initials: L
authors.lastname: Briggs
authors.affiliation: CSIRO Food Futures National Research Flagship & CSIRO Ecosystem Sciences, Australia, PO Box 1700, Canberra, ACT 2601, Australia.
authors.forename: Jian
authors.initials: J
authors.lastname: Wang
authors.affiliation: CSIRO Food Futures National Research Flagship & CSIRO Ecosystem Sciences, Australia, PO Box 1700, Canberra, ACT 2601, Australia.
authors.forename: Amalia
authors.initials: A
authors.lastname: Berna
authors.affiliation: CSIRO Food Futures National Research Flagship & CSIRO Ecosystem Sciences, Australia, PO Box 1700, Canberra, ACT 2601, Australia.
authors.forename: Alisha
authors.initials: A
authors.lastname: Anderson
authors.affiliation: CSIRO Food Futures National Research Flagship & CSIRO Ecosystem Sciences, Australia, PO Box 1700, Canberra, ACT 2601, Australia.
authors.forename: Stephen
authors.initials: S
authors.lastname: Trowell
mesh_terms: D000818:Animals; D017173:Caenorhabditis elegans / Q000378:metabolism*; D002628:Chemoreceptor Cells / Q000378:metabolism*; D015825:Chromosomes, Fungal; D049452:Green Fluorescent Proteins / Q000235:genetics; D018613:Microscopy, Confocal; D010675:Pheromones / Q000378:metabolism*; D010957:Plasmids; D012441:Saccharomyces cerevisiae / Q000235:genetics / Q000378:metabolism*; D029701:Saccharomyces cerevisiae Proteins / Q000378:metabolism*
chemical_list: D010675:Pheromones; D029701:Saccharomyces cerevisiae Proteins; D049452:Green Fluorescent Proteins