O-glycosylation is a major post-translational modification of proteins. Oglycosylated proteins play major roles in eukaryotic cells from fungi to humans. The initial reaction of mannose transfer to serine and threonine residues is catalysed by protein O-mannosyltransferase in the endoplasmic reticulum. Seven PMT (1-7) has been characterized in S. cerevisiae. Phylogenetic analysis showed that protein 0-mannosyltransferases can be divided into three subfamilies, the PMT1, PMT2 and PMT4 subfamilies. Disruption of three different types of PMT genes resulted in death of the yeast cells. In the filamentous fungus Aspergillus fumigatus, 3 orthologs are present in the genome and are called PMT1, PMT2 and PMT4 since every of them belong to a different subfamily. All these proteins showed hydropathy profiles typical of protein O-mannosyltransferase of the PMT family with several transmembranes domains. The role of PMT4 has been now investigated in A. fumigatus and for the first time in filamentous fungi. This gene encoded for a transmembrane protein of 780 amino acids. 916;PMT4 of A. fumigatus has been constructed by gene replacement. The mutant show severe morphological defects : reduced growth, altered mycelium, higher sensitivity to antifungal drugs, reduced conidiation.
Full conference title:
The First International Fungal / Plant Cell Wall Meeting
- International Fungal / Plant Cell Wall Meeting 1st