PLoS Genetics (Oct 2019)

GPCR-mediated glucose sensing system regulates light-dependent fungal development and mycotoxin production.

  • Thaila Fernanda Dos Reis,
  • Laura Mellado,
  • Jessica M Lohmar,
  • Lilian Pereira Silva,
  • Jing-Jiang Zhou,
  • Ana M Calvo,
  • Gustavo H Goldman,
  • Neil A Brown

DOI
https://doi.org/10.1371/journal.pgen.1008419
Journal volume & issue
Vol. 15, no. 10
p. e1008419

Abstract

Read online

Microorganisms sense environmental fluctuations in nutrients and light, coordinating their growth and development accordingly. Despite their critical roles in fungi, only a few G-protein coupled receptors (GPCRs) have been characterized. The Aspergillus nidulans genome encodes 86 putative GPCRs. Here, we characterise a carbon starvation-induced GPCR-mediated glucose sensing mechanism in A. nidulans. This includes two class V (gprH and gprI) and one class VII (gprM) GPCRs, which in response to glucose promote cAMP signalling, germination and hyphal growth, while negatively regulating sexual development in a light-dependent manner. We demonstrate that GprH regulates sexual development via influencing VeA activity, a key light-dependent regulator of fungal morphogenesis and secondary metabolism. We show that GprH and GprM are light-independent negative regulators of sterigmatocystin biosynthesis. Additionally, we reveal the epistatic interactions between the three GPCRs in regulating sexual development and sterigmatocystin production. In conclusion, GprH, GprM and GprI constitute a novel carbon starvation-induced glucose sensing mechanism that functions upstream of cAMP-PKA signalling to regulate fungal development and mycotoxin production.