title: Integration of additional copies of Trichoderma reesei gene encoding protein O-mannosyltransferase I results in a decrease of the enzyme activity and alteration of cell wall composition.
abstract: In fungi, transfer of the first mannosyl residue to proteins during their O-glycosylation is catalyzed by protein O-mannosyltransferases. Integration of additional copies of the pmt1 gene into Trichoderma reesei genome unexpectedly resulted in the silencing of pmt1 expression. Strains carrying the additional copies of pmt1 gene exhibited lower total activity of protein O-mannosyltransferases, lower O- and N-glycosylation of secreted proteins and showed defects in their cell wall composition. Moreover, the strains grew slowly on solid medium and were hypersensitive to an antifungal reagent, Calcofluor white. These results indicate that protein O-mannosyltransferases are required for proper cell wall formation, and their decreased activity influences not only O- but also N-glycosylation.
authors.affiliation: Institute of Biochemistry and Biophysics, Polish Academy of Sciences, Pawińskiego 5a, Warsaw, Poland.
authors.forename: Wioletta
authors.initials: W
authors.lastname: Górka-Nieć
authors.forename: Anna
authors.initials: A
authors.lastname: Kania
authors.forename: Urszula
authors.initials: U
authors.lastname: Perlińska-Lenart
authors.forename: Gabriela
authors.initials: G
authors.lastname: Smoleńska-Sym
authors.forename: Grażyna
authors.initials: G
authors.lastname: Palamarczyk
authors.forename: Joanna S
authors.initials: JS
authors.lastname: Kruszewska
mesh_terms: D002473:Cell Wall / Q000201:enzymology / Q000235:genetics / Q000378:metabolism*; D005656:Fungal Proteins / Q000235:genetics* / Q000378:metabolism*; D018628:Gene Dosage; D006031:Glycosylation; D008364:Mannosyltransferases / Q000235:genetics* / Q000378:metabolism*; D014242:Trichoderma / Q000201:enzymology* / Q000235:genetics / Q000378:metabolism
chemical_list: D005656:Fungal Proteins; D008364:Mannosyltransferases; C082696:protein O-mannosyltransferase