Beta-N-acetylhexosaminidases HEXO1 and HEXO3 are responsible for the formation of paucimannosidic N-glycans in Arabidopsis thaliana.
Beta-N-acetylhexosaminidases HEXO1 and HEXO3 are responsible for the formation of paucimannosidic N-glycans in Arabidopsis thaliana.
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DOI：
10.1074/jbc.m110.178020
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发表时间：
2011-03-25
期刊：
影响因子：
--
通讯作者：
Strasser R
中科院分区：
文献类型：
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作者：
Liebminger E;Veit C;Pabst M;Batoux M;Zipfel C;Altmann F;Mach L;Strasser R
大多数植物糖蛋白含有大量的少甘露糖苷N-聚糖，而不是它们的直接生物合成前体，具有末端N-乙酰葡糖胺残基的复合N-聚糖。我们现在证明，两个β-N-乙酰氨基己糖苷酶（HEXO 1和HEXO 3）驻留在不同的亚细胞区室共同帐户的少甘露糖苷N-聚糖在拟南芥的形成。对hexo基因敲除植物的总N-聚糖分析表明，HEXO 1和HEXO 3对根中少甘露糖苷N-聚糖的产生有相同的贡献，而叶子中的N-聚糖加工更依赖于HEXO 3而不是HEXO 1。由于hexo 1 hexo 3双突变体即使在暴露于不同形式的非生物或生物胁迫下也不表现出任何明显的表型，因此通过下调内源性β-N-乙酰己糖胺酶活性来提高植物中产生的糖蛋白治疗剂的质量应该是可行的。
Most plant glycoproteins contain substantial amounts of paucimannosidic N-glycans instead of their direct biosynthetic precursors, complex N-glycans with terminal N-acetylglucosamine residues. We now demonstrate that two β-N-acetylhexosaminidases (HEXO1 and HEXO3) residing in different subcellular compartments jointly account for the formation of paucimannosidic N-glycans in Arabidopsis thaliana. Total N-glycan analysis of hexo knock-out plants revealed that HEXO1 and HEXO3 contribute equally to the production of paucimannosidic N-glycans in roots, whereas N-glycan processing in leaves depends more heavily on HEXO3 than on HEXO1. Because hexo1 hexo3 double mutants do not display any obvious phenotype even upon exposure to different forms of abiotic or biotic stress, it should be feasible to improve the quality of glycoprotein therapeutics produced in plants by down-regulation of endogenous β-N-acetylhexosaminidase activities.