Gelsolin-Like Domain 3 Plays Vital Roles in Regulating the Activities of the Lily Villin/Gelsolin/Fragmin Superfamily.
Gelsolin-Like Domain 3 Plays Vital Roles in Regulating the Activities of the Lily Villin/Gelsolin/Fragmin Superfamily.
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DOI：
10.1371/journal.pone.0143174
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发表时间：
2015
期刊：
影响因子：
3.7
通讯作者：
Xiang Y
中科院分区：
文献类型：
--
作者：
Qian D;Nan Q;Yang Y;Li H;Zhou Y;Zhu J;Bai Q;Zhang P;An L;Xiang Y
绒毛蛋白/凝胶蛋白/片段蛋白超家族是Ca2+依赖性肌动蛋白结合蛋白（ABPs）的主要群体，参与各种细胞过程。该超家族的成员通常具有3或6个串联凝胶样结构域，每个结构域在肌动蛋白丝动力学中起着不同的作用。虽然大多数G结构域的活性已经被表征，但G3结构域的生化功能仍然知之甚少。在这项研究中，我们仔细比较了ABP29（该家族的新成员，包含百合ABP135的G1-G2结构域）和ABP135G1-G3（包含百合ABP135的G1-G3结构域）的详细生化活性。在高Ca2+水平（200 μM和10 μM）下，ABP135G1-G3比ABP29表现出更强的肌动蛋白切断和/或解聚和成核活性，并且这些蛋白具有相似的肌动蛋白封顶活性。然而，当Ca2+浓度较低（41 nM）时，ABP135G1-G3的capping活性弱于ABP29。此外，与典型的超家族蛋白不同，稀释介导的解聚实验表明，ABP29抑制f -肌动蛋白的解聚。而ABP135G1-G3则加速f -肌动蛋白解聚。这些结果表明，G3结构域在百合绒毛蛋白/凝胶蛋白/片段蛋白超家族蛋白的活性调控中起着特定的作用。
The villin/gelsolin/fragmin superfamily is a major group of Ca2+-dependent actin-binding proteins (ABPs) involved in various cellular processes. Members of this superfamily typically possess three or six tandem gelsolin-like (G) domains, and each domain plays a distinct role in actin filament dynamics. Although the activities of most G domains have been characterized, the biochemical function of the G3 domain remains poorly understood. In this study, we carefully compared the detailed biochemical activities of ABP29 (a new member of this family that contains the G1-G2 domains of lily ABP135) and ABP135G1-G3 (which contains the G1-G3 domains of lily ABP135). In the presence of high Ca2+ levels in vitro (200 and 10 μM), ABP135G1-G3 exhibited greater actin severing and/or depolymerization and nucleating activities than ABP29, and these proteins had similar actin capping activities. However, in the presence of low levels of Ca2+ (41 nM), ABP135G1-G3 had a weaker capping activity than ABP29. In addition, ABP29 inhibited F-actin depolymerization, as shown by dilution-mediated depolymerization assay, differing from the typical superfamily proteins. In contrast, ABP135G1-G3 accelerated F-actin depolymerization. All of these results demonstrate that the G3 domain plays specific roles in regulating the activities of the lily villin/gelsolin/fragmin superfamily proteins.