title: Aspergillus oxylipin signaling and quorum sensing pathways depend on g protein-coupled receptors.
abstract: Oxylipins regulate Aspergillus development and mycotoxin production and are also involved in Aspergillus quorum sensing mechanisms. Despite extensive knowledge of how these oxylipins are synthesized and what processes they regulate, nothing is known about how these signals are detected and transmitted by the fungus. G protein-coupled receptors (GPCR) have been speculated to be involved as they are known oxylipin receptors in mammals, and many putative GPCRs have been identified in the Aspergilli. Here, we present evidence that oxylipins stimulate a burst in cAMP in A. nidulans, and that loss of an A. nidulans GPCR, gprD, prevents this cAMP accumulation. A. flavus undergoes an oxylipin-mediated developmental shift when grown at different densities, and this regulates spore, sclerotial and aflatoxin production. A. flavus encodes two putative GprD homologs, GprC and GprD, and we demonstrate here that they are required to transition to a high-density development state, as well as to respond to spent medium of a high-density culture. The finding of GPCRs that regulate production of survival structures (sclerotia), inoculum (spores) and aflatoxin holds promise for future development of anti-fungal therapeutics.
authors.affiliation: Department of Bacteriology and Department of Medical Microbiology and Immunology, 1550 Linden Drive, Madison, WI 53706, USA.
authors.forename: Katharyn J
authors.initials: KJ
authors.lastname: Affeldt
authors.forename: Marion
authors.initials: M
authors.lastname: Brodhagen
authors.forename: Nancy P
authors.initials: NP
authors.lastname: Keller
mesh_terms: D001231:Aspergillus flavus / Q000378:metabolism*; D001233:Aspergillus nidulans / Q000378:metabolism*; D000242:Cyclic AMP / Q000378:metabolism; D005656:Fungal Proteins / Q000378:metabolism*; D054883:Oxylipins / Q000378:metabolism*; D053038:Quorum Sensing; D043562:Receptors, G-Protein-Coupled / Q000378:metabolism*; D015398:Signal Transduction
chemical_list: D005656:Fungal Proteins; D054883:Oxylipins; D043562:Receptors, G-Protein-Coupled; D000242:Cyclic AMP
keywords: Aspergillus; G protein-coupled receptor (GPCR); aflatoxin; oxylipin; quorum sensing; sclerotia 