Understanding Aspergillus fumigatus galactosaminogalactan biosynthesis: A few questions remain

François Le Mauff; Donald C Sheppard

doi:10.1016/j.tcsw.2023.100095

Understanding Aspergillus fumigatus galactosaminogalactan biosynthesis: A few questions remain

Cell Surf. 2023 Jan 7:9:100095. doi: 10.1016/j.tcsw.2023.100095. eCollection 2023 Dec.

Authors

François Le Mauff^{1

2}, Donald C Sheppard^{1

2

3

4}

Affiliations

¹ Infectious Disease and Immunity in Global Health Program, Research Institute of the McGill University Health Centre, Montreal, Quebec, Canada.
² McGill Interdisciplinary Initiative in Infection and Immunity, Montreal, Quebec, Canada.
³ Department of Microbiology and Immunology, McGill University, Montreal, Quebec, Canada.
⁴ Department of Medicine, McGill University, Montreal, Quebec, Canada.

Abstract

Half a century after their discovery, polymers of N-acetylgalactosamine produced by the Aspergilli have garnered new interest as mediators of fungal virulence. Recent work has focused on the Aspergillus fumigatus secreted and cell wall-associated heteropolymer, galactosaminogalactan (GAG). This polymer, composed of galactose (Gal) and partially deacetylated N-acetylgalactosamine (GalNAc), plays a role in a variety of pathogenic processes including biofilm formation, immune modulation and evasion, and resistance to antifungals. Given its many potential contributions to fungal pathogenesis, GAG is a promising therapeutic target for novel antifungal strategies. As such, several studies have sought to elucidate the biosynthetic pathways required for GAG production and secretion. Herein we review the progress made in the understanding of the molecular mechanisms underlying GAG synthesis and identify several gaps in our understanding of this process.

Keywords: A. fumigatus; Biofilm; Biosynthesis; GAG, galactosaminogalactan; GH, glycoside hydrolase; Gal, galactose; GalNAc, N-acetylgalactosamine; Galactosaminogalactan; Polysaccharide.

Publication types

Review