Earticle

초록

영어

Protein O-mannosylation is an evolutionarily conserved protein modification of fundamental importance from bacteria to humans. Protein O-mannosylation in yeast and higher eukaryotes is initiated by protein O-mannosyltransferases (PMTs) that transfer mannose from Dol-P-Man to serine or threonine residues of secretory proteins. We identified and characterized two H. polymorpha PMT1 subfamily genes, HpPMT1-1 and HpPMT1-2, in the thermotolerant methylotrophic yeast Hansenula polymorpha. The HpPMT1-1 and HpPMT1-2 gene encodes two Pmt protein isoforms with an overall protein sequence identity of 52.3 % and 24.6 %, respectively, to Saccharomyces cerevisiae Pmt1p. The analysis of hydropathy profiles predicts the two H. polymorpha Pmt proteins to be integral membrane proteins with multiple transmembrane domains. The promoters of both H. polymorpha genes contain an HpHAC1p binding site, in consistent with their induced expression under UPR condition. Whereas the deletion of HpPMT1-1 resulted in apparent cell growth defects under cell wall stress induction conditions and a temperature sensitive phenotype, any detectable defects were not detected in the HpPMT1-2 deletion. However, the Hppmt1-2 mutant showed a significant sensitivity to the PMT1 inhibitor R3A-1c. Furthermore, analysis of cell wall mannoproteins with lectin blotting indicated significant decrease in O-mannosylation in the Hppmt1-1 mutant, but not in Hppmt1-2, compared to the wild type strain. We constructed a HA epitope-tagged version of HpPmt1-1p and confirmed that this construct was fully functional in vivo and localized at the membrane fraction. Altogether, our data support a major role of HpPMT1-1 in protein O-mannosylation and a redundant function of HpPMT1-2.

저자

• Hyunah Kim [ Lab. of Molecular System Biology, Dept. of Life Science, Chung-Ang University, Seoul 155-756, Korea. ]
• Dong-jik Lee [ Lab. of Molecular System Biology, Dept. of Life Science, Chung-Ang University, Seoul 155-756, Korea. ]
• Hye Yun Moon [ Lab. of Molecular System Biology, Dept. of Life Science, Chung-Ang University, Seoul 155-756, Korea. ]
• Seon Ah Cheon [ Lab. of Molecular System Biology, Dept. of Life Science, Chung-Ang University, Seoul 155-756, Korea. ]
• Jeong-Nam Park [ Lab. of Molecular System Biology, Dept. of Life Science, Chung-Ang University, Seoul 155-756, Korea. ]
• Min Jeong Sohn [ Lab. of Molecular System Biology, Dept. of Life Science, Chung-Ang University, Seoul 155-756, Korea. ]
• Doo-Byoung Oh [ Korea Research Institute of Bioscience and Biotechnology (KRIBB) ]
• Ohsuk Kwon [ Korea Research Institute of Bioscience and Biotechnology (KRIBB) ]
• Hyun Ah Kang [ Lab. of Molecular System Biology, Dept. of Life Science, Chung-Ang University, Seoul 155-756, Korea. ]

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간행물

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• 간행물명

  한국당과학회 학술대회

• 간기

  연간

• 수록기간

  2006~2022

• 십진분류

  KDC 517 DDC 614