STRUCTURAL STUDIES OF COMPLEXES OF CYCLOPHILIN B

亲环蛋白B复合物的结构研究

• 批准号: 8171522
• 负责人: Kalle B Gehring
• 金额: $ 1.4万
• 依托单位: CORNELL UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2010
• 资助国家: 美国
• 起止时间: 2010-07-01 至 2011-06-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8171522
• 关键词: Antibodies; Autoimmune Diseases; Binding; Binding Sites; Calnexin; Cells; Complex; Computer Retrieval of Information on Scientific Projects Database; Cyclophilins; Data; Disulfides; ERp57; Endoplasmic Reticulum; Funding; Glycoproteins; Grant; Home environment; Human Pathology; Institution; Isomerase; Lectin; Maps; Mediating; Molecular; Pathway interactions; Protein Disulfide Isomerase; Proteins; Quality Control; Research; Research Personnel; Resolution; Resources; Roentgen Rays; Site-Directed Mutagenesis; Source; Structure; Surface; Time; Titrations; Trefoil Motif; United States National Institutes of Health; Viral; Virus Diseases; arm; calreticulin; cyclophilin B; insight; novel; protein folding; protein protein interaction

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. Calnexin (CNX) and calreticulin (CRT) are key components of the calnexin cycle, which is responsible for quality control pathways in the endoplasmic reticulum (ER) (ref 1). CNX and CRT contain an extended arm-like P-domain and a globular lectin domain, which specifically recognizes Glc1Man9GlcNAc2 glycoproteins. The tip of the P-domain is a binding site for a protein disulphide isomerase ERp57, which assists in folding of disulphide-containing proteins. Recently, we determined the molecular envelope of ERp57 using small-angle X-ray scattering and the crystal structure of the central bb` fragment (ref 2). NMR titrations and site-directed mutagenesis were used to map the calnexin interaction surface of ERp57 to the bb` domains. Recently, we have found that the P-domain of CNX/CRT binds another ER resident protein, cyclophilin B, a peptidyl-prolyl cys-trans isomerase. We obtained crystals of cyclophilin B in complex with the P-domain, which diffract to 2.8 ¿ resolution on a home source. We are requesting beam time to obtain higher resolution data. These studies will provide novel insights into the protein-protein interactions involved in protein folding in the endoplasmic reticulum. This is relevant to multiple human pathologies ranging from autoimmune diseases (antibody and MHC synthesis) to viral infections (ER-mediated viral entry). REFERENCES 1) Ellgaard, L. & Helenius, A. (2001) Curr Opin Cell Biol 13, 431-37. 2) Kozlov, G. et al. (2006) Structure 14, 1331-39.

这个子项目是许多利用 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。 钙连接蛋白（CNX）和钙网蛋白（CRT）是钙连接蛋白循环的关键组分，负责内质网（ER）中的质量控制途径（参考文献1）。CNX和CRT含有一个延伸的臂状P结构域和一个球状凝集素结构域，可特异性识别Glc 1 Man 9 GlcNAc 2糖蛋白。P-结构域的尖端是蛋白质二硫化物异构酶ERp 57的结合位点，其有助于含二硫化物的蛋白质的折叠。最近，我们使用小角X射线散射和中心bb`片段的晶体结构确定了ERp 57的分子包络（参考文献2）。NMR滴定和定点诱变用于将ERp 57的钙连接蛋白相互作用表面映射到bb`结构域。 最近，我们发现CNX/CRT的P-结构域结合另一种ER驻留蛋白亲环素B，一种肽基脯氨酰cys-反式异构酶。我们获得了亲环蛋白B与P-结构域复合的晶体，其在家庭来源上的分辨率为2.8。我们正在请求光束时间以获得更高分辨率的数据。 这些研究将提供新的见解蛋白质-蛋白质相互作用参与蛋白质折叠的内质网。 这与多种人类病理学相关，从自身免疫性疾病（抗体和MHC合成）到病毒感染（ER介导的病毒进入）。 引用 1)埃尔加德湖& Helenius，A.（2001）Curr Opin Cell Biol 13，431-37. 2)Kozlov，G.等人（2006）Structure 14，1331-39.