Djuric Ivona, Siebrasse Jan Peter, Schulze Ulf, Granado Daniel, Schlüter Marc A, Kubitscheck Ulrich, Pavenstädt Hermann, Weide Thomas
Internal Medicine D, Molecular Nephrology, University Hospital of Muenster, Albert-Schweitzer-Campus 1, 48149 Muenster, Germany.
Institute of Physical and Theoretical Chemistry, Rheinische Friedrich-Wilhelms University Bonn, Wegelerstraße 12, 53115 Bonn, Germany.
Biochim Biophys Acta. 2016 Jun;1863(6 Pt A):1208-17. doi: 10.1016/j.bbamcr.2016.03.008. Epub 2016 Mar 11.
The physiological function of epithelia depends on an asymmetric distribution of their membrane domains. Polarity proteins play a crucial role for distribution processes, however, little is known about their mobility in epithelial cells. In this study, we analyzed the intracellular and plasma-membrane-associated mobility of fluorescence-labeled Crb3A and Crb3B. Both variants belong to the Crumbs protein family, which control size and identity of apical membranes in epithelial cells. Fluorescence recovery after photo-bleaching measurements revealed different mobilities for the two Crb3 variants. They also differentially affected mobility and localization of the Pals1/Mpp5 protein, which binds to Crb3A but not to Crb3B. In addition, tracking of intracellular vesicles indicated that Crb3A containing vesicles are slightly more immobile than Crb3B ones. Taken together, our data revealed different intracellular mobility patterns for Crb3A and Crb3B.
上皮细胞的生理功能取决于其膜结构域的不对称分布。极性蛋白在分布过程中起关键作用，然而，关于它们在上皮细胞中的流动性却知之甚少。在本研究中，我们分析了荧光标记的Crb3A和Crb3B在细胞内和质膜相关的流动性。这两种变体都属于Crb3蛋白家族，该家族控制上皮细胞顶端膜的大小和特性。光漂白后荧光恢复测量显示两种Crb3变体具有不同的流动性。它们还对与Crb3A而非Crb3B结合的Pals1/Mpp5蛋白的流动性和定位产生不同影响。此外，对细胞内囊泡的追踪表明，含有Crb3A的囊泡比含有Crb3B的囊泡移动性稍低。综上所述，我们的数据揭示了Crb3A和Crb3B不同的细胞内流动性模式。
