Lack of the evidence for the enzymatic catabolism of Man1GlcNAc2 in Saccharomyces cerevisiae |
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| Authors: | Tanim Jabid Hossain Hiroto Hirayama Yoichiro Harada |
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| Institution: | 1. Glycometabolome Team, Systems Glycobiology Research Group, RIKEN-Max Planck Joint Research Center for Systems Chemical Biology, Global Research Cluster , Saitama, Japan;2. Graduate School of Science and Engineering, Saitama University , Saitama, Japan;3. Glycometabolome Team, Systems Glycobiology Research Group, RIKEN-Max Planck Joint Research Center for Systems Chemical Biology, Global Research Cluster , Saitama, Japan;4. Department of Systems Biology in Thromboregulation, Kagoshima University Graduate School of Medical and Dental Sciences , Kagoshima, Japan |
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| Abstract: | In the cytosol of Saccharomyces cerevisiae, most of the free N-glycans (FNGs) are generated from misfolded glycoproteins by the action of the cytoplasmic peptide: N-glycanase (Png1). A cytosol/vacuole α-mannosidase, Ams1, then trims the FNGs to eventually form a trisaccharide composed of Manβ1,4GlcNAc β1,4GlcNAc (Man1GlcNAc2). Whether or not the resulting Man1GlcNAc2 is enzymatically degraded further, however, is currently unknown. The objective of this study was to unveil the fate of Man1GlcNAc2 in S. cerevisiae. Quantitative analyses of the FNGs revealed a steady increase in the amount of Man1GlcNAc2 produced in the post-diauxic and stationary phases, suggesting that this trisaccharide is not catabolized during this period. Inoculation of the stationary phase cells into fresh medium resulted in a reduction in the levels of Man1GlcNAc2. However, this reduction was caused by its dilution due to cell division in the fresh medium. Our results thus indicate that Man1GlcNAc2 is not enzymatically catabolized in S. cerevisiae. |
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| Keywords: | free N-glycan Saccharomyces cerevisiae Man1GlcNAc2 catabolism |
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