Dynamin-Like Protein B of Dictyostelium Contributes to Cytokinesis Cooperatively with Other Dynamins
Dynamin-Like Protein B of Dictyostelium Contributes to Cytokinesis Cooperatively with Other Dynamins
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DOI：
10.3390/cells8080781
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发表时间：
2019-08-01
期刊：
影响因子：
6
通讯作者：
Yumura, Shigehiko
中科院分区：
文献类型：
--
作者：
Fujimoto, Koushiro;Tanaka, Masahito;Yumura, Shigehiko
Dynamin 是一种大型 GTP 酶，负责多种细胞过程，例如内吞作用、细胞器分裂和胞质分裂。社会性变形虫盘基网柄菌 (Dictyostelium discoideum) 具有五种动力样蛋白：dymA、dymB、dlpA、dlpB 和 dlpC。 DymA、dlpA 或 dlpB 缺陷的细胞表现出胞质分裂缺陷。发现 DlpA 和 dlpB 从早期就共定位于卵裂沟，dymA 定位于连接两个子细胞的细胞间桥，表明这些动力在不同的分裂阶段促进胞质分裂。全内反射荧光显微镜显示 dlpA 和 dlpB 共定位于沟皮层的各个点。然而，dlpA 和 dlpB 并不与网格蛋白共定位，表明它们不参与网格蛋白介导的内吞作用。事实上，dlpA 没有定位在 dlpB 无效细胞中的沟槽处，反之亦然，以及其他几条证据表明，dlpA 和 dlpB 的异源寡聚化是它们与沟槽结合所必需的。异源寡聚物直接或间接与肌动蛋白丝结合，将其稳定在收缩环中。有趣的是，dlpA（而不是 dlpB）独立于 dlpB 在吞噬杯处积累。我们的结果表明 dlpA 和 dlpB 的异源寡聚物与 dymA 协同促进胞质分裂。
Dynamin is a large GTPase responsible for diverse cellular processes, such as endocytosis, division of organelles, and cytokinesis. The social amoebozoan, Dictyostelium discoideum, has five dynamin-like proteins: dymA, dymB, dlpA, dlpB, and dlpC. DymA, dlpA, or dlpB-deficient cells exhibited defects in cytokinesis. DlpA and dlpB were found to colocalize at cleavage furrows from the early phase, and dymA localized at the intercellular bridge connecting the two daughter cells, indicating that these dynamins contribute to cytokinesis at distinct dividing stages. Total internal reflection fluorescence microscopy revealed that dlpA and dlpB colocalized at individual dots at the furrow cortex. However, dlpA and dlpB did not colocalize with clathrin, suggesting that they are not involved in clathrin-mediated endocytosis. The fact that dlpA did not localize at the furrow in dlpB null cells and vice versa, as well as other several lines of evidence, suggests that hetero-oligomerization of dlpA and dlpB is required for them to bind to the furrow. The hetero-oligomers directly or indirectly associate with actin filaments, stabilizing them in the contractile rings. Interestingly, dlpA, but not dlpB, accumulated at the phagocytic cups independently of dlpB. Our results suggest that the hetero-oligomers of dlpA and dlpB contribute to cytokinesis cooperatively with dymA.