Corbacho Isaac, Olivero Isabel, Hohmann Stefan, Sunnerhagen Per, Hernández Luis M
Department of Microbiology, University of Extremadura, 06071, Badajoz, Spain.
Antonie Van Leeuwenhoek. 2006 Apr-May;89(3-4):485-94. doi: 10.1007/s10482-005-9047-5. Epub 2006 Apr 19.
The MNN2 gene of S. cerevisiae encodes an alpha (1,2) mannosyl transferase required for branching the outer chain of N-linked oligosaccharides (Rayner J.C. and Munro S. 1998. J. Biol. Chem. 273: 26836-26843) and it also seems to have some effect on the transfer of mannosyl phosphate groups to the inner core (Olivero I. et al. 2000. FEBS Lett. 475: 111-116). In order to reveal possible interactions of MNN2 expression with other cellular pathways, we analyzed the transcriptome of the deletion mutant S. cerevisiae mnn2 Delta using cDNA microarrays. We found 151 genes that showed an altered expression level of > or =2-fold, 58 of them up-regulated and 93 down-regulated. Quite a high proportion of these genes (29%) encode unclassified proteins. In contrast to other defects affecting the integrity of the cell wall, deletion of MNN2 does not stimulate the expression of any of the genes included in the previously defined 'cell wall compensatory cluster' (Lagorce et al. 2003. J. Biol. Chem. 278: 20345-20357). We also found that 15% of the selected genes are related to central metabolic pathways. In addition, the mnn2 Delta strain seems to have a certain level of stimulation of DNA processing reactions while some genes involved in intracellular transport pathways are under-regulated.
酿酒酵母的MNN2基因编码一种α(1,2)甘露糖基转移酶，该酶是N-连接寡糖外链分支所必需的（Rayner J.C.和Munro S. 1998.《生物化学杂志》273: 26836 - 26843），并且它似乎对甘露糖磷酸基团向内核的转移也有一定作用（Olivero I.等人2000.《欧洲生物化学学会联合会快报》475: 111 - 116）。为了揭示MNN2表达与其他细胞途径可能的相互作用，我们使用cDNA微阵列分析了酿酒酵母缺失突变体mnn2Δ的转录组。我们发现151个基因的表达水平变化≥2倍，其中58个上调，93个下调。这些基因中有相当高比例（29%）编码未分类的蛋白质。与影响细胞壁完整性的其他缺陷不同，MNN2的缺失不会刺激先前定义的“细胞壁补偿簇”中包含的任何基因的表达（Lagorce等人2003.《生物化学杂志》278: 20345 - 20357）。我们还发现所选基因中有15%与中心代谢途径相关。此外，mnn2Δ菌株似乎对DNA加工反应有一定程度的刺激，而一些参与细胞内运输途径的基因表达下调。
