| Резюме: |
Human bestrophin-1 (hBest1) is a Ca2+-dependent transmembrane protein that is expressed in the retinal pigment epithelium, and mutations in the BEST1 gene cause retinal degenerations collectively termed “bestrophinopathies”. The present thesis describes the results of a large number of genetic, biochemical, biophysical, physicochemical and molecular biological integrated studies, which are important for understanding the relationship between the structure and function of the hBest1 channel protein and its pathophysiological significance. Here, we show and discuss the state-of-the-art knowledge and understanding of the surface organization of hBest1, its interactions with essential membrane lipids (such as POPC, SM, and Chol) in models of biological membranes, and its association with various microdomains (e.g., lipid rafts) in cell membranes. This knowledge is fundamental to understanding how the activity of hBest1 channel molecules is modulated and regulated in cells. Large-scale cell culture studies on the sorting of hBest1 and its mutant forms are included, showing that at least three sorting signals as well as phosphorylation are crutial for proper targeting of hBest1 to the basolateral membrane. We have shown that the expression of hBest1 in cells leads to a change in lipid metabolism, and the localization of the protein in the plasma membrane causes its "fluidization" and a reduction in the size of the ordered regions in it. The detected partial association (~30%) of hBest1 with lipid rafts defines the main role of the different microdomains for the surface (self)organization and activity of the protein.
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