O-glycosylation.
O-Glycosylation in many fungal species is initiated in the endoplasmic reticulum by protein mannosyltransferases (Pmt-proteins), which transfer mannose to serine or threonine residues, and it is completed by mannosyltransferases (Mnt-proteins) in the Golgi. In this review, some recent results on O-glycosylation in the human fungal pathogen Candida albicans are discussed and compared to the corresponding knowledge in the non-pathogenic yeast Saccharomyces cerevisiae. The Pmt-family in C. albicans comprises five isoforms, of which Pmt1p and Pmt6p have been studied in detail. Surprisingly, O-glycosylation mediated by Pmt-proteins is required not only for the modification of several secreted and cell-wall proteins, but also affects yeast-hyphal morphogenesis (dimorphism) and resistance to several antifungal compounds. Furthermore, Pmt1- and Pmt6p-activities maximize adherence to host cells and determine or contribute to virulence in models of systemic infection. Thus, O-glycosylation processes directly and/or indirectly affect several virulence traits of C. albicans and can be considered as potential antifungal targets.
Ernst
J F
JF
Institut für Mikrobiologie, Heinnch-Heine-Universität Düsseldorf, Germany. ernstj@rz.uni-duesseldorf.de
Prill
S K
SK
D000935:Antifungal Agents / Q000494:pharmacology; D002176:Candida albicans / Q000187:drug effects / Q000254:growth & development / Q000378:metabolism*; D004721:Endoplasmic Reticulum / Q000378:metabolism*; D006031:Glycosylation; D006056:Golgi Apparatus / Q000201:enzymology; D007527:Isoenzymes / Q000737:chemistry / Q000502:physiology; D008358:Mannose / Q000378:metabolism*; D008364:Mannosyltransferases / Q000737:chemistry / Q000502:physiology*; D012694:Serine / Q000378:metabolism*; D013912:Threonine / Q000378:metabolism*; D014774:Virulence
D000935:Antifungal Agents; D007527:Isoenzymes; D013912:Threonine; D012694:Serine; D008364:Mannosyltransferases; D008358:Mannose