Protein O-Glycosylation in Fungi: Diverse Structures and Multiple Functions

  title={Protein O-Glycosylation in Fungi: Diverse Structures and Multiple Functions},
  author={Masatoshi Goto},
  journal={Bioscience, Biotechnology, and Biochemistry},
  pages={1415 - 1427}
  • M. Goto
  • Published 23 June 2007
  • Biology
  • Bioscience, Biotechnology, and Biochemistry
Protein glycosylation is essential for eukaryotic cells from yeasts to humans. When compared to N-glycosylation, O-glycosylation is variable in sugar components and the mode of linkages connecting the sugars. In fungi, secretory proteins are commonly mannosylated by protein O-mannosyltransferase (PMT) in the endoplasmic reticulum, and subsequently glycosylated by several glycosyltransferases in the Golgi apparatus to form glycoproteins with diverse O-glycan structures. Protein O-glycosylation… 

Protein glycosylation pathways in filamentous fungi.

The N-glycosylation pathway in the cytoplasm and endoplasmic reticulum was found to be highly conserved evolutionarily across all the filamentous fungi considered in the study, including those of medical/agricultural/industrial importance for which genomes have been recently sequenced.

Synthesis and biological roles of O-glycans in insects

The availability of sequenced genomes and genetic tools to create mutants with clear phenotypes makes insects an interesting model system to study O-glycosylation, and an overview of the current knowledge is provided, mainly obtained from the model organism Drosophila melanogaster.

Role of Protein Glycosylation in Interactions of Medically Relevant Fungi with the Host

This review focuses on describing the relationship between protein glycosylation and the host–immune interaction in medically relevant fungal species.

Distinct roles of N- and O-glycans in cellulase activity and stability

It is reported that, depending on where they are attached, glycans play substantially different roles for the enzyme in thermal and proteolytic stability, substrate binding, and substrate turnover, which provides fundamental insights into how glycans affect critical properties of biomass-degrading enzymes.

Engineering of glycosylation in yeast and other fungi: current state and perspectives

An overview of the most significant recently reported approaches for engineering the glycosylation pathways in yeasts and fungi is provided.

Glycosylation of cellulase: a novel strategy for improving cellulase.

The potential roles of glycosylation on the characteristics and function of cellulases are discussed and the use of certain cultivation, inducer, and alteration of engineering gly cosylation pathway can enable the rational control of cellulase glycosYLation.

Structural, Evolutionary, and Functional Analysis of the Protein O-Mannosyltransferase Family in Pathogenic Fungi

The origin of Pmts in fungi is analysed and the most important phenotypes associated with Pmt mutants in pathogenic fungi are reviewed, highlighting the enormous relevance of these glycotransferases for fungal pathogenic development.

N-glycoprotein macroheterogeneity: biological implications and proteomic characterization

The importance of the analysis of macroheterogeneity for a complete understanding of glycoprotein biosynthesis and function is highlighted, and how advances in mass spectrometry glycoproteomics will enable analysis of this critical facet of glyCoprotein structural diversity is emphasized.



Molecular characterization of protein O-mannosyltransferase and its involvement in cell-wall synthesis in Aspergillus nidulans.

The results indicate that PmtA is required for the formation of a normal cell wall in Aspergillus nidulans, and indicates that protein O-glycosylation is essential for protein modification and plays important roles in eukaryotic cells.

PMT1, the gene for a key enzyme of protein O-glycosylation in Saccharomyces cerevisiae.

It was observed that protein O-mannosylation in the disruptant had decreased only to about 40-50%, indicating the existence of an additional transferase which had not been measured by the in vitro enzyme assay, which led to a complete loss of in vitro mannosyltransferase activity.

Protein O-mannosylation.

The PMT gene family: protein O‐glycosylation in Saccharomyces cerevisiae is vital.

The results show that protein O‐glycosylation is essential for cell wall rigidity and cell integrity and that this protein modification, therefore, is vital for Saccharomyces cerevisiae.

The dolichol pathway of N-linked glycosylation.

Protein-O-glycosylation in yeast: protein-specific mannosyltransferases.

The results clearly indicate that the various protein O-mannosyltransferases have different specificities for protein substrates.

Roles of O-Mannosylation of Aberrant Proteins in Reduction of the Load for Endoplasmic Reticulum Chaperones in Yeast*

O-Mannosylation may function as a fail-safe mechanism for the ERad by solubilizing the aberrant proteins that overflowed from the ERAD pathway and reducing the load for ER chaperones.

O‐Mannosylation precedes and potentially controls the N‐glycosylation of a yeast cell wall glycoprotein

It is shown that the Pmt4 and Pmt1/Pmt2 mannosyltransferases glycosylate different domains of the Ccw5 protein, thereby mannosyating several consecutive serine and threonine residues, and that O‐mannosylation by PMT4 precedes N‐glycosylation.