Department of Medicine, UMass Medical School, Worcester, MA, USA.
Department of Biology, Ashoka University P.O. Rai, Sonepat, India.
Mol Microbiol. 2021 Sep;116(3):974-995. doi: 10.1111/mmi.14787. Epub 2021 Jul 27.
For the protist parasite Entamoeba histolytica, endocytic processes, such as phagocytosis, are essential for its survival in the human gut. The actin cytoskeleton is involved in the formation of pseudopods and phagosomal vesicles by incorporating a number of actin-binding and modulating proteins along with actin in a temporal manner. The actin dynamics, which comprises polymerization, branching, and depolymerization is very tightly regulated and takes place directionally at the sites of initiation of phagocytosis. Formin and profilin are two actin-binding proteins that are known to regulate actin cytoskeleton dynamics and thereby, endocytic processes. In this article, we report the participation of formin and profilin in E. histolytica phagocytosis and propose that these two proteins interact with each other and their sequential recruitment at the site is required for the successful completion of phagocytosis. The evidence is based on detailed microscopic, live imaging, interaction studies, and expression downregulation. The cells downregulated for expression of formin show absence of profilin at the site of phagocytosis, whereas downregulation of profilin does not affect formin localization.
对于原生动物寄生虫溶组织内阿米巴（Entamoeba histolytica），内吞过程，如吞噬作用，对于其在人类肠道中的生存是必不可少的。肌动蛋白细胞骨架通过将许多肌动蛋白结合蛋白和调节蛋白与肌动蛋白一起在时间上整合，参与伪足和吞噬体囊泡的形成。肌动蛋白动力学，包括聚合、分支和解聚，受到非常严格的调节，并在吞噬作用起始部位定向发生。formin 和 profilin 是两种已知调节肌动蛋白细胞骨架动力学从而调节内吞作用的肌动蛋白结合蛋白。在本文中，我们报告了formin 和 profilin 参与溶组织内阿米巴吞噬作用，并提出这两种蛋白相互作用，并且它们在该部位的顺序募集对于吞噬作用的成功完成是必需的。该证据基于详细的显微镜、实时成像、相互作用研究和表达下调。表达下调的细胞中，在吞噬作用部位缺乏 profilin，而 profilin 的下调不影响 formin 的定位。
