Evidence for an essential deglycosylation-independent activity of PNGase in Drosophila melanogaster.
Evidence for an essential deglycosylation-independent activity of PNGase in Drosophila melanogaster.
复制标题
DOI：
10.1371/journal.pone.0010545
复制
发表时间：
2010-05-10
期刊：
影响因子：
3.7
通讯作者：
Suzuki T
中科院分区：
文献类型：
--
作者：
Funakoshi Y;Negishi Y;Gergen JP;Seino J;Ishii K;Lennarz WJ;Matsuo I;Ito Y;Taniguchi N;Suzuki T
肽：n -聚糖酶（PNGase）是一种从糖肽/糖蛋白中释放n -连接聚糖的酶。这种酶在酵母和小鼠的内质网相关降解（ERAD）途径中起作用，但这种活性的生物学重要性尚不清楚。在这项研究中，我们表征了黑腹果蝇细胞质pngas的同源性，pngas样（Pngl）。发现Pngl的分子量为~ 74K，主要定位于细胞质中。Pngl缺乏CXXC基序，而CXXC基序对其他物种的酶活性至关重要，因此似乎不具有Pngl酶活性，尽管它仍然保持碳水化合物结合活性。我们在Pngl基因座上产生了微缺失，以研究该蛋白在体内的功能重要性。消除Pngl会导致幼虫和蛹发育严重迟缓或停滞，存活的突变体成年雄虫和雌虫经常不育。最重要的是，Pngl的普遍表达挽救了这些表型，这清楚地表明，这些表型后果确实是由于缺乏功能性Pngl。有趣的是，一个假定的“催化无活性”突变体不能挽救生长延迟表型，这表明该蛋白的生化活性对其生物学功能很重要。Pngl被证明是正常发育过渡的必然产物，除去糖基化活性外，其生化特性对其生物学功能也很重要。
Peptide:N-glycanase (PNGase) is an enzyme which releases N-linked glycans from glycopeptides/glycoproteins. This enzyme plays a role in the ER-associated degradation (ERAD) pathway in yeast and mice, but the biological importance of this activity remains unknown. In this study, we characterized the ortholog of cytoplasmic PNGases, PNGase-like (Pngl), in Drosophila melanogaster. Pngl was found to have a molecular weight of ∼74K and was mainly localized in the cytosol. Pngl lacks a CXXC motif that is critical for enzymatic activity in other species and accordingly did not appear to possess PNGase activity, though it still retains carbohydrate-binding activity. We generated microdeletions in the Pngl locus in order to investigate the functional importance of this protein in vivo. Elimination of Pngl led to a serious developmental delay or arrest during the larval and pupal stages, and surviving mutant adult males and females were frequently sterile. Most importantly, these phenotypes were rescued by ubiquitous expression of Pngl, clearly indicating that those phenotypic consequences were indeed due to the lack of functional Pngl. Interestingly, a putative “catalytic-inactive” mutant could not rescue the growth-delay phenotype, indicating that a biochemical activity of this protein is important for its biological function. Pngl was shown to be inevitable for the proper developmental transition and the biochemical properties other than deglycosylation activity is important for its biological function.
登录
查看更多内容
影响因子：
4.1
作者：
Chantret, I;Frénoy, JP;Moore, SEH
通讯作者：
Moore, SEH
影响因子：
7.4
作者：
Della Mea, M;Caparrós-Ruiz, D;Rigau, J
通讯作者：
Rigau, J
影响因子：
4.8
作者：
Hirayama, Hiroto;Seino, Junichi;Suzuki, Tadashi
通讯作者：
Suzuki, Tadashi
影响因子：
7.2
作者：
Diepold, Andreas;Li, Guangtao;Brunner, Frederic
通讯作者：
Brunner, Frederic
影响因子：
4.8
作者：
Katiyar, S;Suzuki, T;Lennarz, WJ
通讯作者：
Lennarz, WJ