Molecular characterization of protein O-mannosyltransferase and its involvement in cell-wall synthesis in Aspergillus nidulans.
Protein O-glycosylation is essential for protein modification and plays important roles in eukaryotic cells. O-Mannosylation of proteins occurs in the filamentous fungus Aspergillus. The structure and function of the pmtA gene, encoding protein O-d-mannosyltransferase, which is responsible for the initial O-mannosylation reaction in Aspergillus nidulans, was characterized. Disruption of the pmtA gene resulted in the reduction of in vitro protein O-d-mannosyltransferase activity to 6 % of that of the wild-type strain and led to underglycosylation of an extracellular glucoamylase. The pmtA disruptant exhibited abnormal cell morphology and alteration in carbohydrate composition, particularly reduction in the skeletal polysaccharides in the cell wall. The results indicate that PmtA is required for the formation of a normal cell wall in A. nidulans.
Oka
Takuji
T
Department of Bioscience and Biotechnology, Faculty of Agriculture, Kyushu University, Fukuoka 812-8581, Japan.
Hamaguchi
Tetsu
T
Department of Bioscience and Biotechnology, Faculty of Agriculture, Kyushu University, Fukuoka 812-8581, Japan.
Sameshima
Yuka
Y
Department of Bioscience and Biotechnology, Faculty of Agriculture, Kyushu University, Fukuoka 812-8581, Japan.
Goto
Masatoshi
M
Department of Bioscience and Biotechnology, Faculty of Agriculture, Kyushu University, Fukuoka 812-8581, Japan.
Furukawa
Kensuke
K
Department of Bioscience and Biotechnology, Faculty of Agriculture, Kyushu University, Fukuoka 812-8581, Japan.
D001233:Aspergillus nidulans / Q000201:enzymology* / Q000235:genetics / Q000254:growth & development; D001483:Base Sequence; D002473:Cell Wall / Q000378:metabolism*; D003470:Culture Media; D005656:Fungal Proteins / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism; D017353:Gene Deletion; D006031:Glycosylation; D008364:Mannosyltransferases / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism; D008969:Molecular Sequence Data; D017422:Sequence Analysis, DNA; D014158:Transcription, Genetic
D003470:Culture Media; D005656:Fungal Proteins; D008364:Mannosyltransferases