Identification of proteins that interact with mammalian peptide:N-glycanase and implicate this hydrolase in the proteasome-dependent pathway for protein degradation
Identification of proteins that interact with mammalian peptide:N-glycanase and implicate this hydrolase in the proteasome-dependent pathway for protein degradation
复制标题
DOI：
10.1073/pnas.201393498
复制
发表时间：
2001-09-25
影响因子：
11.1
通讯作者：
Lennarz, WJ
中科院分区：
文献类型：
--
作者：
Park, H;Suzuki, T;Lennarz, WJ
肽：n -聚糖酶（PNGase）从糖肽和糖蛋白中切割低聚糖链。最近，从酵母菌到哺乳动物等多种真核生物中都发现了胞质PNGase的氨基酸序列，这表明去糖基化可能在一些分解代谢过程中起着核心作用。一些证据表明，细胞质酶参与了新合成糖蛋白的质量控制系统。以小鼠PNGase为靶点进行双杂交文库筛选，得到了几种pnase相互作用蛋白，这些蛋白先前与蛋白酶体依赖的蛋白质降解有关：mHR23B，泛素，19S蛋白酶体的调节亚基，以及含有泛素调节基序（UBX）和泛素相关基序（UBA）的蛋白。这些发现通过使用双杂交系统进一步证实了体外结合试验或大小分离试验。这些结果表明，PNGase可能是哺乳动物细胞中蛋白酶体介导的错误折叠糖蛋白的有效降解所必需的。
Peptide:N-glycanase (PNGase) cleaves oligosaccharide chains from glycopeptides and glycoproteins. Recently the deduced amino acid sequence of a cytoplasmic PNGase has been identified in various eukaryotes ranging from yeast to mammals, suggesting that deglycosylation may play a central role in some catabolic process. Several lines of evidence indicate that the cytoplasmic enzyme is involved in the quality control system for newly synthesized glycoproteins. Two-hybrid library screening by using mouse PNGase as the target yielded several PNGase-interacting proteins that previously had been implicated in proteasome-dependent protein degradation: mHR23B, ubiquitin, a regulatory subunit of the 19S proteasome, as well as a protein containing an ubiquitin regulatory motif (UBX) and an ubiquitin-associated motif (UBA). These findings by using the two-hybrid system were further confirmed either by in vitro binding assays or size fractionation assays. These results suggest that PNGase may be required for efficient proteasome-mediated degradation of misfolded glycoproteins in mammalian cells.