Synergies between Aip1p and capping protein subunits (Acp1p and Acp2p) in clathrin-mediated endocytosis and cell polarization in fission yeast.
Synergies between Aip1p and capping protein subunits (Acp1p and Acp2p) in clathrin-mediated endocytosis and cell polarization in fission yeast.
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DOI：
10.1091/mbc.e13-01-0005
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发表时间：
2014-11-05
影响因子：
3.3
通讯作者：
Pollard TD
中科院分区：
文献类型：
--
作者：
Berro J;Pollard TD
结果表明，除了帽肌动蛋白丝，Aip 1 p和帽蛋白亚基Acp 2 p也参与肌动蛋白补丁极化的间期，但不是在有丝分裂。相反，Acp 1 p不参与细胞极化。Aip 1 p与肌动蛋白解聚因子（ADF）/cofilin合作，在体外和体内分解肌动蛋白丝，并建议帽肌动蛋白丝倒刺结束。我们解决Aip 1 p和加帽蛋白异二聚体Acp 1 p/Acp 2 p在网格蛋白介导的内吞作用在裂殖酵母之间的协同作用。使用定量显微镜和新的方法，我们已经开发的数据比对和分析，我们表明，异二聚体的加帽蛋白可以取代Aip 1 p，但Aip 1 p不能取代内吞补丁的加帽蛋白。我们的定量分析表明，肌动蛋白网络是放射状组织，并在胞吞囊泡从质膜释放之前被交联剂fimmagnesium压实。帽蛋白和Aip 1 p通过保持肌动蛋白丝足够接近以进行交联来帮助维持网状结构中肌动蛋白丝的高密度。我们的实验还揭示了新的细胞功能的Acp 1 p和Acp 2 p独立于他们的封盖活动。我们确定了两个独立的途径，控制内吞部位的极化，一个依赖于acp 2+和aip 1+在间期和其他独立的acp 1+，acp 2+，和aip 1+在有丝分裂。
It is shown that, in addition to capping actin filaments, Aip1p and the capping protein subunit Acp2p are also involved in actin patch polarization in interphase, but not in mitosis. In contrast, Acp1p is not involved in cell polarization. Aip1p cooperates with actin-depolymerizing factor (ADF)/cofilin to disassemble actin filaments in vitro and in vivo, and is proposed to cap actin filament barbed ends. We address the synergies between Aip1p and the capping protein heterodimer Acp1p/Acp2p during clathrin-mediated endocytosis in fission yeast. Using quantitative microscopy and new methods we have developed for data alignment and analysis, we show that heterodimeric capping protein can replace Aip1p, but Aip1p cannot replace capping protein in endocytic patches. Our quantitative analysis reveals that the actin meshwork is organized radially and is compacted by the cross-linker fimbrin before the endocytic vesicle is released from the plasma membrane. Capping protein and Aip1p help maintain the high density of actin filaments in meshwork by keeping actin filaments close enough for cross-linking. Our experiments also reveal new cellular functions for Acp1p and Acp2p independent of their capping activity. We identified two independent pathways that control polarization of endocytic sites, one depending on acp2+ and aip1+ during interphase and the other independent of acp1+, acp2+, and aip1+ during mitosis.