Glycoprotein hypersecretion alters the cell wall in Trichoderma reesei strains expressing the Saccharomyces cerevisiae dolichylphosphate mannose synthase gene.
Expression of the Saccharomyces cerevisiae DPM1 gene (coding for dolichylphosphate mannose synthase) in Trichoderma reesei (Hypocrea jecorina) increases the intensity of protein glycosylation and secretion and causes ultrastructural changes in the fungal cell wall. In the present work, we undertook further biochemical and morphological characterization of the DPM1-expressing T. reesei strains. We established that the carbohydrate composition of the fungal cell wall was altered with an increased amount of N-acetylglucosamine, suggesting an increase in chitin content. Calcofluor white staining followed by fluorescence microscopy indicated changes in chitin distribution. Moreover, we also observed a decreased concentration of mannose and alkali-soluble beta-(1,6) glucan. A comparison of protein secretion from protoplasts with that from mycelia showed that the cell wall created a barrier for secretion in the DPM1 transformants. We also discuss the relationships between the observed changes in the cell wall, increased protein glycosylation, and the greater secretory capacity of T. reesei strains expressing the yeast DPM1 gene.
Perlińska-Lenart
Urszula
U
Institute of Biochemistry and Biophysics, Polish Academy of Sciences, Pawińskiego 5a, 02-106 Warsaw, Poland.
Orlowski
Jacek
J
Laudy
Agnieszka E
AE
Zdebska
Ewa
E
Palamarczyk
Grazyna
G
Kruszewska
Joanna S
JS
D001709:Biotechnology / Q000379:methods; D002473:Cell Wall / Q000737:chemistry* / Q000378:metabolism; D002686:Chitin / Q000032:analysis; D006023:Glycoproteins / Q000378:metabolism*; D006031:Glycosylation; D008358:Mannose / Q000032:analysis; D008364:Mannosyltransferases / Q000235:genetics / Q000378:metabolism*; D012441:Saccharomyces cerevisiae / Q000201:enzymology* / Q000235:genetics; D014242:Trichoderma / Q000201:enzymology* / Q000235:genetics; D015854:Up-Regulation; D047071:beta-Glucans / Q000032:analysis
D006023:Glycoproteins; D047071:beta-Glucans; D002686:Chitin; C064197:beta-1,6-glucan; D008364:Mannosyltransferases; C022755:dolichyl-phosphate beta-D-mannosyltransferase; D008358:Mannose