The high osmolarity glycerol (HOG) pathway in fungi^†

Abstract

While fungi are widely occupying nature, many species are responsible for devastating mycosis in humans. Such niche diversity explains how quick fungal adaptation is necessary to endow the capacity of withstanding fluctuating environments and to cope with host-imposed conditions. Among all the molecular mechanisms evolved by fungi, the most studied one is the activation of the phosphorelay signalling pathways, of which the high osmolarity glycerol (HOG) pathway constitutes one of the key molecular apparatus underpinning fungal adaptation and virulence. In this review, we summarize the seminal knowledge of the HOG pathway with its more recent developments. We specifically described the HOG-mediated stress adaptation, with a particular focus on osmotic and oxidative stress, and point out some lags in our understanding of its involvement in the virulence of pathogenic species including, the medically important fungi Candida albicans, Cryptococcus neoformans, and Aspergillus fumigatus, compared to the model yeast Saccharomyces cerevisiae. Finally, we also highlighted some possible applications of the HOG pathway modifications to improve the fungal-based production of natural products in the industry.

Keywords:

• Fungi
• signalling pathway
• phosphorylation
• two-component system
• stress adaptation
• virulence

Author contributions

H.Y. draft-wrote the manuscript except for the biotechnology section, which was draft-written by N.S.S., L.O.L., and R.C. A.C., J.P.B., R.C., and N.P. revised the manuscript. The final drafting was done by R.C., V.C., and N.P.

Disclosure statement

No potential conflict of interest was reported by the authors.

Additional information

Funding

HY was supported by a fellowship from Association AZM (Tripoli, Lebanon). RC, NSS, and LOL were supported by grant numbers CF-58550 (CONACyT) and IN-210519 (PAPIIT, DGAPA, UNAM).