Characterization of O-mannosyltransferase family in Schizosaccharomyces pombe.
Characterization of O-mannosyltransferase family in Schizosaccharomyces pombe.
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DOI：
10.1016/j.bbrc.2005.03.033
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发表时间：
2005-05
影响因子：
3.1
通讯作者：
N. Tanaka;Yasuko Fujita;Shotaro Suzuki;M. Morishita;Y. Giga‐Hama;C. Shimoda;K. Takegawa
中科院分区：
文献类型：
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作者：
N. Tanaka;Yasuko Fujita;Shotaro Suzuki;M. Morishita;Y. Giga‐Hama;C. Shimoda;K. Takegawa
蛋白质O-糖基化是真核细胞中重要的蛋白质修饰。在酿酒酵母中，O-甘露糖基化是由O-甘露糖基转移酶基因产物（Pmt 1 p-7 p）在内质网腔中启动的。对粟酒裂殖酵母基因组数据库的搜索揭示了总共三种O-糖苷甘露糖基转移酶同系物（ogm 1+、ogm 2+和ogm 4+），与酿酒酵母PMT 1、PMT 2和PMT 4密切相关。虽然个别ogm基因没有被发现是必需的，但ogm 1 Δ和ogm 4 Δ突变体表现出异常的形态，并且在交配期间不能凝集。ogm 4 Δ突变体的表型不被ogm 1+或ogm 2+的过表达所补充，这表明每种Ogm蛋白不具有重叠的功能。异源表达几丁质酶。在ogm突变体中，几丁质酶的O-糖基化水平降低。用绿色荧光蛋白（GFP）标记的Fus 1 p。在ogm 4 Δ细胞中，酿酒酵母特异性地不被糖基化并在高尔基体中积累。这些结果表明Ogm蛋白启动的O-糖基化起着至关重要的生理作用，并可作为S.粟酒
Protein O-glycosylation is an essential protein modification in eukaryotic cells. In Saccharomyces cerevisiae, O-mannosylation is initiated in the lumen of the endoplasmic reticulum by O-mannosyltransferase gene products (Pmt1p–7p). A search of the Schizosaccharomyces pombe genome database revealed a total of three O-glycoside mannosyltransferase homologs (ogm1+, ogm2+, and ogm4+), closely related to Saccharomyces cerevisiae PMT1, PMT2, and PMT4. Although individual ogm genes were not found to be essential, ogm1Δ and ogm4Δ mutants exhibited aberrant morphology and failed to agglutinate during mating. The phenotypes of the ogm4Δ mutant were not complemented by overexpression of ogm1+or ogm2+, suggesting that each of the Ogm proteins does not have overlapping functions. Heterologous expression of a chitinase from S. cerevisiae in the ogm mutants revealed that O-glycosylation of chitinase had decreased in ogm1Δ cells. A GFP-tagged Fus1p from S. cerevisiae was specifically not glycosylated and accumulated in the Golgi in ogm4Δ cells. These results indicate that O-glycosylation initiated by Ogm proteins plays crucial physiological roles and can serve as a sorting determinant for protein transport of membrane glycoproteins in S. pombe.