Comparative functional analysis of the OCH1 mannosyltransferase families in Aspergillus fumigatus and Saccharomyces cerevisiae.
Alpha1,6-linked mannans are an essential component of the Aspergillus fumigatus galactomannan, which is either GPI-anchored to the plasma membrane or covalently bound to the polysaccharide core of the cell wall. In Saccharomyces cerevisiae, the OCH1 gene encodes an alpha1,6-mannosyltransferase that initiates the synthesis of the alpha1,6 linked-mannan. In the A. fumigatus genome, four orthologous genes of Saccharomyces cerevisiae ScOCH1 gene were identified. Single deletion and the quadruple deletion mutants (Afoch1-4Delta) were constructed in A. fumigatus. No phenotype different from the wild-type strain was observed in all single and the quadruple mutants. The corresponding cDNAs of the AfOCH1-4 A. fumigatus orthologues were expressed in the S. cerevisiae Scoch1Delta mutant. Among the four orthologues, only AfOCH1 complemented the aggregation phenotype, the growth inhibition, the hypersensitivity to hygromycin and the protein glycosylation defects observed in the Scoch1Deltamutant.
Lambou
Karine
K
Unité des Aspergillus, Institut Pasteur, 25 Rue du Docteur Roux, 75724 Paris Cedex 15, France.
Perkhofer
Susanne
S
Fontaine
Thierry
T
Latge
Jean-Paul
JP
D000935:Antifungal Agents / Q000494:pharmacology; D001232:Aspergillus fumigatus / Q000201:enzymology* / Q000235:genetics; D002448:Cell Adhesion; D002455:Cell Division; D002934:Cinnamates / Q000494:pharmacology; D017353:Gene Deletion; D005816:Genetic Complementation Test; D006921:Hygromycin B / Q000031:analogs & derivatives / Q000494:pharmacology; D008351:Mannans / Q000378:metabolism; D008364:Mannosyltransferases / Q000235:genetics / Q000378:metabolism*; D008562:Membrane Glycoproteins / Q000235:genetics / Q000378:metabolism*; D010802:Phylogeny; D012441:Saccharomyces cerevisiae / Q000187:drug effects / Q000201:enzymology* / Q000235:genetics / Q000254:growth & development; D029701:Saccharomyces cerevisiae Proteins / Q000235:genetics / Q000378:metabolism*; D017386:Sequence Homology, Amino Acid
D000935:Antifungal Agents; D002934:Cinnamates; D008351:Mannans; D008562:Membrane Glycoproteins; C075636:OCH1 protein, S cerevisiae; D029701:Saccharomyces cerevisiae Proteins; C022901:(1-6)-alpha-glucomannan; D006921:Hygromycin B; C026273:hygromycin A; D008364:Mannosyltransferases