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质膜蛋白脂质相互作用的微模式研究

Probing lipid interactions of plasma membrane proteins: a micropatterning approach
课程网址: http://videolectures.net/biophysics2018_fulop_micropatterning_app...  
主讲教师: Gergo Fulop
开课单位: 应用物理研究所
开课时间: 2018-07-09
课程语种: 英语
中文简介:
众所周知,脂质和蛋白质不仅是真核细胞质膜的独立成分,而且它们的排列、动力学和功能是相互依存的。除了直接的脂质-蛋白质相互作用外,跨膜蛋白质被认为是结合环状脂质壳,它们或多或少与蛋白质紧密相关。此外,高度有序的纳米级膜结构域已被提出用于区分蛋白质及其相互作用,但迄今为止尚未直接观察到。在这项研究中,我们使用蛋白质微模式结合单分子追踪直接测量活细胞质膜中的脂质-蛋白质相互作用:不同的荧光标记跨膜相关蛋白(POI)被捕获并富集在质膜中明确定义的区域内,留下耗尽POI的区域,作为参考区域。从脂质和蛋白质相对于POI模式的分布和扩散行为,我们能够得出POI局部膜环境的结论。我们发现,基于血凝素跨膜结构域(HA-mGFP)的棕榈酰化蛋白质对其膜环境的影响远远超过跨膜螺旋的大小。对于一个棕榈酰化缺陷突变体也观察到了同样的效果,这使我们排除了HA-mGFP周围形成更有序的膜结构域是导致蛋白质大小明显增加的原因。
课程简介: It is well established that lipids and proteins are not just independent components of the plasma membrane of eukaryotic cells but that their arrangement, dynamics and function are interdependent.Besides direct lipid-protein interaction, transmembrane proteins are thought to bind a shell of annular lipids, which are more or less tightly associated with the proteins. Furthermore, highly ordered nanoscopic membrane domains have been proposed to act to compartmentalize proteins and their interactions, but have thus far not been directly observed. In this study, we use protein micropatterning combined with single-molecule tracking to directly measure lipid-protein interactions in the plasma membrane of living cells: different fluorescently labelled transmembrane proteins of interest (POIs) were captured and enriched within well-defined areas in the plasma membrane, leaving regions depleted of POI, which function as reference areas. From the distribution and diffusion behaviour of lipids and proteins with respect to the POI patterns, we were able to conclude on the local membrane environment of the POI. We found that a palmitoylated protein based on the transmembrane domain of hemagglutinin (HA-mGFP) influences its membrane environment well beyond the size of the transmembrane helix. The same effect was observed for a palmitoylation-deficient mutant allowing us to rule out formation of a more ordered membrane domain around HA-mGFP as the cause for this apparently increased protein size.
关 键 词: 脂质; 蛋白质; 蛋白质微模式
课程来源: 视频讲座网
数据采集: 2021-11-13:zkj
最后编审: 2021-11-13:zkj
阅读次数: 123