与霍乱毒素A1亚基突变体相互作用蛋白的筛选  

Identification of a novel protein interacting with CTA1(S63F)

作　　者：杨淑静[1] 曹诚[1] 马清钧[1] 

机构地区：[1]军事医学科学院生物工程研究所,北京100850

出　　处：《中华微生物学和免疫学杂志》2001年第6期668-671,共4页Chinese Journal of Microbiology and Immunology

基　　金：国家自然科学基金资助项目 ( 397890 10 )

摘　　要：目的　寻找新的与霍乱毒素A1亚基 (CTA1)突变体 (S6 3F)相互作用的蛋白 ,来探讨CT佐剂活性的分子机理。方法　应用酵母双杂交技术 ,以CTA1(S6 3F)为诱饵蛋白筛选人脾细胞cDNA文库 ,并通过共转染、免疫共沉淀和Western杂交在哺乳动物细胞COS 7中确证诱饵蛋白和候选蛋白之间的相互作用。结果　筛选获得一个与HLAⅠ类分子α亚基高度同源的蛋白 ,这个蛋白在酵母核内以及COS 7细胞中都显示出与CTA1(S6 3F)的相互作用。结论　CTA1(S6 3F)与HLAⅠ类分子α亚基的相互作用可能导致HLAⅠ类分子进入“膜筏” ,引起膜筏不断聚集增大 ,聚集到一定程度后筏相关酪氨酸蛋白激酶活化 ,启动胞内信号的级联传递 。Objective Searching for a novel protein interacting with CTA1(S63F) to dissect the mechanisms of mucosal adjuvanticity of cholera toxin. Methods CTA1(S63F) was used as 'bait protein' to screen a human spleen cDNA library. Then the protein protein interaction was confirmed by coimmunoprecipitation after the proteins being transiently coexpressed in mammal cell COS 7. Results A novel protein with significant homology with α subunit of HLA class Ⅰmolecule was identified. The protein interacted with CTA1(S63F) both in yeast nucleus and in mammal cell COS 7. Conclusions HLA class Ⅰ molecules interacting with CTA1(S63F) may induce their entry into membrane rafts, the glycolipid enriched membrane fraction of the plasma membrane. At the cellular level, this results in the synergistic co aggregation of HLA class Ⅰ molecules and membrane rafts. This process is essential for the activation of Src family tyrosine kinases, which are constitutively associated with the membrane rafts. Activation of raft associated tyrosine kinases has pleiotropic effects on cell function, affecting antigen presentation, proliferation and cytokine release, those appear to be important for mucosal adjuvanticity of cholera toxin. [

关 键 词：霍乱毒素 佐剂 酵母双杂交 膜筏 突变体 相互作用蛋白 

分 类 号：R392[医药卫生—免疫学]