@article {689,
	title = {Controlled expression of branch-forming mannosyltransferase is critical for mycobacterial lipoarabinomannan biosynthesis.},
	journal = {J Biol Chem},
	volume = {285},
	year = {2010},
	month = {2010 Apr 30},
	pages = {13326-36},
	abstract = {Lipomannan (LM) and lipoarabinomannan (LAM) are phosphatidylinositol-anchored glycans present in the mycobacterial cell wall. In Mycobacterium smegmatis, the mannan core of LM/LAM constitutes a linear chain of 20-25 alpha1,6-mannoses elaborated by 8-9 alpha1,2-monomannose side branches. At least two alpha1,6-mannosyltransferases mediate the linear mannose chain elongation, and one branching alpha1,2-mannosyltransferase (encoded by MSMEG_4247) transfers monomannose branches. An MSMEG_4247 deletion mutant accumulates branchless LAM and interestingly fails to accumulate LM, suggesting an unexpected role of mannose branching for LM synthesis or maintenance. To understand the roles of MSMEG_4247-mediated branching more clearly, we analyzed the MSMEG_4247 deletion mutant in detail. Our study showed that the deletion mutant restored the synthesis of wild-type LM and LAM upon the expression of MSMEG_4247 at wild-type levels. In striking contrast, overexpression of MSMEG_4247 resulted in the accumulation of dwarfed LM/LAM, although monomannose branching was restored. The dwarfed LAM carried a mannan chain less than half the length of wild-type LAM and was elaborated by an arabinan that was about 4 times smaller. Induced overexpression of an elongating alpha1,6-mannosyltransferase competed with the overexpressed branching enzyme, alleviating the dwarfing effect of the branching enzyme. In wild-type cells, LM and LAM decreased in quantity in the stationary phase, and the expression levels of branching and elongating mannosyltransferases were reduced in concert, presumably to avoid producing abnormal LM/LAM. These data suggest that the coordinated expressions of branching and elongating mannosyltransferases are critical for mannan backbone elongation.},
	keywords = {Bacterial Proteins, Cell Wall, Gene Deletion, Lipopolysaccharides, Mannose, Mannosyltransferases, Mycobacterium smegmatis},
	issn = {1083-351X},
	doi = {10.1074/jbc.M109.077297},
	author = {Sena, Chubert B C and Fukuda, Takeshi and Miyanagi, Kana and Matsumoto, Sohkichi and Kobayashi, Kazuo and Murakami, Yoshiko and Maeda, Yusuke and Kinoshita, Taroh and Morita, Yasu S}
}
@article {698,
	title = {PIG-V involved in transferring the second mannose in glycosylphosphatidylinositol.},
	journal = {J Biol Chem},
	volume = {280},
	year = {2005},
	month = {2005 Mar 11},
	pages = {9489-97},
	abstract = {Glycosylphosphatidylinositol (GPI) is a glycolipid that anchors many proteins to the eukaryotic cell surface. The biosynthetic pathway of GPI is mediated by sequential additions of sugars and other components to phosphatidylinositol. Four mannoses in the GPI are transferred from dolichol-phosphate-mannose (Dol-P-Man) and are linked through different glycosidic linkages. Therefore, four Dol-P-Man-dependent mannosyltransferases, GPI-MT-I, -MT-II, -MT-III, and -MT-IV for the first, second, third, and fourth mannoses, respectively, are required for generation of GPI. GPI-MT-I (PIG-M), GPI-MT-III (PIG-B), and GPI-MT-IV (SMP3) were previously reported, but GPI-MT-II remains to be identified. Here we report the cloning of PIG-V involved in transferring the second mannose in the GPI anchor. Human PIG-V encodes a 493-amino acid, endoplasmic reticulum (ER) resident protein with eight putative transmembrane regions. Saccharomyces cerevisiae protein encoded in open reading frame YBR004c, which we termed GPI18, has 25\% amino acid identity to human PIG-V. Viability of the yeast gpi18 deletion mutant was restored by human PIG-V cDNA. PIG-V has two functionally important conserved regions facing the ER lumen. Taken together, we suggest that PIG-V is the second mannosyltransferase in GPI anchor biosynthesis.},
	keywords = {Amino Acid Sequence, Animals, Cell Line, Tumor, CHO Cells, Cloning, Molecular, Conserved Sequence, Cricetinae, DNA Primers, Glioma, Glycosylphosphatidylinositols, Humans, Mannose, Mannosyltransferases, Molecular Sequence Data, Open Reading Frames, Rats, Restriction Mapping, Saccharomyces cerevisiae, Sequence Alignment, Sequence Homology, Amino Acid},
	issn = {0021-9258},
	doi = {10.1074/jbc.M413867200},
	author = {Kang, Ji Young and Hong, Yeongjin and Ashida, Hisashi and Shishioh, Nobue and Murakami, Yoshiko and Morita, Yasu S and Maeda, Yusuke and Kinoshita, Taroh}
}
