PEPTIDE:N-GLYCANASE

肽：N-聚糖酶

• 批准号: 7602299
• 负责人: HERMANN SCHINDELIN
• 金额: $ 0.43万
• 依托单位: BROOKHAVEN SCIENCE ASSOC-BROOKHAVEN LAB
• 依托单位国家: 美国
• 财政年份: 2007
• 资助国家: 美国
• 起止时间: 2007-07-01 至 2008-06-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7602299
• 关键词: ATP phosphohydrolase; Adopted; Binding; Biochemical; C-terminal; Catalytic Domain; Cell Survival; Complex; Computer Retrieval of Information on Scientific Projects Database; Data; Data Collection; Degradation Pathway; Endoplasmic Reticulum; Enzymes; Eukaryota; Eukaryotic Cell; Funding; Grant; Institution; Length; Modeling; Mus; N-terminal; Peptide N-Glycosidase; Polysaccharides; Process; Protein Family; Proteins; Reporting; Research; Research Personnel; Resources; Solutions; Source; Structure; Time; United States National Institutes of Health; interest; multicatalytic endopeptidase complex; novel; protein degradation; protein misfolding; sugar; yeast protein

This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. The subproject and investigator (PI) may have received primary funding from another NIH source, and thus could be represented in other CRISP entries. The institution listed is for the Center, which is not necessarily the institution for the investigator. The endoplasmic reticulum-related protein degradation (ERAD) pathway, where misfolded proteins in the ER are transported through the retro-translocon, ubiquinated, and degraded by the proteasome, is essential for cell viability. Before proteasome degradation, the N-glycan on the ERAD substrates is processed by the Peptide:N-glycanase (PNGase). We tried to illustrate the function of PNGase by studying its structure. We recently solved the structure of the catalytic domain of mouse PNGase (mPNGase), which shows a similar fold as the yeast protein. In addition to the catalytic domain, PNGase in higher eukaryotes has both N- and C-terminal extensions. Our structural and biochemical studies on the C-terminal domain of mPNGase identified it as a sugar-recognizing motif. However, the function of the N-terminal domain is unknown. The N-terminal domain has no sequence similarity with other proteins and may adopt a novel fold. Recently it was reported that mPNGase directly interacts with P97/VCP, an AAA ATPase family protein. We proposed an escort model in which P97 functions as a protein interacting platform to present misfolded proteins from the ER to mPNGase and ubiquitinating enzymes. Our biochemical data showed that the N-terminal domain of mPNGase binds to the C-terminal region of P97. This is the first time that a protein-interacting function of the mPNGase N-terminal domain has been established. This is very interesting since it was generally believed that P97 interacts with its effector proteins through its N-terminal domain. The structure of full length P97 has been solved, however, the C-terminal region could not be visualized in the structure. To investigate the function of the N-terminal domain of mPNGase and the details of its interaction with P97, crystallographic studies on these proteins and their complexes are being undertaken. We have recently obtained crystals of the N-terminal domain in its apo-state and in complex with a fragment of P97 and expect them to be ready for data collection and structure solution by the time the RapiData course starts.

这个子项目是许多研究子项目中的一个 由NIH/NCRR资助的中心赠款提供的资源。子项目和 研究者（PI）可能从另一个NIH来源获得了主要资金， 因此可以在其他CRISP条目中表示。所列机构为 研究中心，而研究中心不一定是研究者所在的机构。 内质网相关蛋白降解（ERAD）途径，其中错误折叠的蛋白质在ER中通过逆转录转运子转运，泛素化，并由蛋白酶体降解，是细胞活力所必需的。在蛋白酶体降解前，ERAD底物上的N-聚糖由肽：N-聚糖酶（PNGase）处理。我们试图通过研究PNGase的结构来阐明其功能。我们最近解决了小鼠PNGase（mPNGase）的催化结构域的结构，它显示了类似的折叠作为酵母蛋白。除了催化结构域，高等真核生物中的PNGase具有N-和C-末端延伸。我们对mPNGase的C-末端结构域的结构和生物化学研究确定其为糖识别基序。然而，N-末端结构域的功能是未知的。N-末端结构域与其他蛋白质没有序列相似性，并且可能采用新的折叠。 最近有报道mPNGase直接与AAA ATP酶家族蛋白P97/VCP相互作用。我们提出了一个护送模型，其中P97作为一个蛋白质相互作用平台，将错误折叠的蛋白质从ER呈递给mPNGase和泛素化酶。我们的生化数据表明，N-末端结构域的mPNGase结合的C-末端区域的P97。这是第一次建立了mPNGase N-末端结构域的蛋白质相互作用功能。这是非常有趣的，因为通常认为P97通过其N-末端结构域与其效应蛋白相互作用。全长P97的结构已被解析，然而，在结构中不能看到C-末端区域。为了研究mPNGase的N-末端结构域的功能及其与P97相互作用的细节，正在对这些蛋白质及其复合物进行晶体学研究。我们最近获得了N-末端结构域的晶体，其处于脱辅基状态，并与P97的片段复合，并期望它们在RapiData课程开始时准备好进行数据收集和结构解析。