Elucidating Key Motifs Required for Arp2/3-Dependent and Independent Actin Nucleation by Las17/WASP.
Elucidating Key Motifs Required for Arp2/3-Dependent and Independent Actin Nucleation by Las17/WASP.
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DOI：
10.1371/journal.pone.0163177
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发表时间：
2016
期刊：
影响因子：
3.7
通讯作者：
Ayscough KR
中科院分区：
文献类型：
--
作者：
Allwood EG;Tyler JJ;Urbanek AN;Smaczynska-de Rooij II;Ayscough KR
肌动蛋白成核是肌动蛋白聚合过程中的关键限速步骤，对该过程的严格调节对于确保肌动蛋白丝仅在特定时间和细胞的限定区域形成至关重要。Arp 2/3是一种具有良好特征的蛋白质复合物，可以促进新细丝的成核，尽管其活性需要额外的成核促进因子（NPF）。这些因子中最受认可的是WASP蛋白家族，其包含单体肌动蛋白和Arp 2/3的结合基序。以前，我们证明了酵母WASP同源物，Las 17，除了激活Arp 2/3也可以从头成核肌动蛋白丝，独立于Arp 2/3。这种活性取决于其富含聚脯氨酸的区域。通过生物化学和体内分析，我们现在已经确定了聚脯氨酸区域内的肌动蛋白丝的成核和伸长所需的关键基序，并解决了WH 2结构域在没有Arp 2/3的肌动蛋白成核背景下的作用。我们还证明了全长Las 17能够结合脂质体，从而产生将新生肌动蛋白丝直接连接到Las 17已被招募的特定膜位点的可能性。总体而言，我们建议，Las 17功能作为从头肌动蛋白丝形成的关键启动子在内吞位点的成核，伸长和束缚新生的细丝，然后作为一个平台，Arp 2/3的招聘和功能。
Actin nucleation is the key rate limiting step in the process of actin polymerization, and tight regulation of this process is critical to ensure actin filaments form only at specific times and at defined regions of the cell. Arp2/3 is a well-characterised protein complex that can promote nucleation of new filaments, though its activity requires additional nucleation promotion factors (NPFs). The best recognized of these factors are the WASP family of proteins that contain binding motifs for both monomeric actin and for Arp2/3. Previously we demonstrated that the yeast WASP homologue, Las17, in addition to activating Arp2/3 can also nucleate actin filaments de novo, independently of Arp2/3. This activity is dependent on its polyproline rich region. Through biochemical and in vivo analysis we have now identified key motifs within the polyproline region that are required for nucleation and elongation of actin filaments, and have addressed the role of the WH2 domain in the context of actin nucleation without Arp2/3. We have also demonstrated that full length Las17 is able to bind liposomes giving rise to the possibility of direct linkage of nascent actin filaments to specific membrane sites to which Las17 has been recruited. Overall, we propose that Las17 functions as the key initiator of de novo actin filament formation at endocytic sites by nucleating, elongating and tethering nascent filaments which then serve as a platform for Arp2/3 recruitment and function.
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DOI：
10.1038/nrm2867
发表时间：
2010-04
期刊：
Nature reviews. Molecular cell biology
影响因子：
--
作者：
通讯作者：
--
ARP2/3调节剂在肌动蛋白组装和内吞作用中的不同作用。
影响因子：
9.8
作者：
Galletta BJ;Chuang DY;Cooper JA
通讯作者：
Cooper JA
影响因子：
64.5
作者：
Kaksonen, M;Toret, CP;Drubin, DG
通讯作者：
Drubin, DG
影响因子：
4.8
作者：
Klein, DE;Lee, A;Lemmon, MA
通讯作者：
Lemmon, MA
影响因子：
11.8
作者：
Sun, Yidi;Martin, Adam C.;Drubin, David G.
通讯作者：
Drubin, David G.