Environment-induced same-sex mating in the yeast Candida albicans through the Hsf1-Hsp90 pathway

PLoS Biol. 2019 Mar 13;17(3):e2006966. doi: 10.1371/journal.pbio.2006966. eCollection 2019 Mar.

Abstract

While sexual reproduction is pervasive in eukaryotic cells, the strategies employed by fungal species to achieve and complete sexual cycles is highly diverse and complex. Many fungi, including Saccharomyces cerevisiae and Schizosaccharomyces pombe, are homothallic (able to mate with their own mitotic descendants) because of homothallic switching (HO) endonuclease-mediated mating-type switching. Under laboratory conditions, the human fungal pathogen Candida albicans can undergo both heterothallic and homothallic (opposite- and same-sex) mating. However, both mating modes require the presence of cells with two opposite mating types (MTLa/a and α/α) in close proximity. Given the predominant clonal feature of this yeast in the human host, both opposite- and same-sex mating would be rare in nature. In this study, we report that glucose starvation and oxidative stress, common environmental stresses encountered by the pathogen, induce the development of mating projections and efficiently permit same-sex mating in C. albicans with an "a" mating type (MTLa/a). This induction bypasses the requirement for the presence of cells with an opposite mating type and allows efficient sexual mating between cells derived from a single progenitor. Glucose starvation causes an increase in intracellular oxidative species, overwhelming the Heat Shock transcription Factor 1 (Hsf1)- and Heat shock protein (Hsp)90-mediated stress-response pathway. We further demonstrate that Candida TransActivating protein 4 (Cta4) and Cell Wall Transcription factor 1 (Cwt1), downstream effectors of the Hsf1-Hsp90 pathway, regulate same-sex mating in C. albicans through the transcriptional control of the master regulator of a-type mating, MTLa2, and the pheromone precursor-encoding gene Mating α factor precursor (MFα). Our results suggest that mating could occur much more frequently in nature than was originally appreciated and that same-sex mating could be an important mode of sexual reproduction in C. albicans.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Candida albicans / metabolism*
  • Candida albicans / physiology*
  • Fungal Proteins / genetics
  • Fungal Proteins / metabolism*
  • Gene Expression Regulation, Fungal
  • Genes, Mating Type, Fungal / genetics
  • Genes, Mating Type, Fungal / physiology
  • HSP90 Heat-Shock Proteins / genetics
  • HSP90 Heat-Shock Proteins / metabolism*
  • Heat Shock Transcription Factors / genetics
  • Heat Shock Transcription Factors / metabolism*
  • Signal Transduction / genetics
  • Signal Transduction / physiology

Substances

  • Fungal Proteins
  • HSP90 Heat-Shock Proteins
  • Heat Shock Transcription Factors

Grants and funding

National Natural Science Foundation of China http://www.nsfc.gov.cn/ (grant number 31625002, 31370175, 31600121, 31570139). Grant Number 31625002 and 31370175 to GH; Grant Number 31600121 to GG; Grant Number 31570139 to LT. The funder had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript. National Science and Technology Major Project http://program.most.gov.cn/ (grant number 2018ZX10101004-003-002). Received by GH. The funder had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.