Arp2/3 复合物的异构体多样性决定了肌动蛋白丝动力学。
Isoform diversity in the Arp2/3 complex determines actin filament dynamics.
机构信息
Cellular Signalling and Cytoskeletal Function, The Francis Crick Institute, Lincoln's Inn Fields Laboratory, 44 Lincoln's Inn Fields, London, WC2A 3LY, UK.
Laboratoire d'Enzymologie et Biochimie Structurale, I2BC, CNRS, 91198 Gif-sur-Yvette, France.
出版信息
Nat Cell Biol. 2016 Jan;18(1):76-86. doi: 10.1038/ncb3286. Epub 2015 Dec 14.
The Arp2/3 complex consists of seven evolutionarily conserved subunits (Arp2, Arp3 and ARPC1-5) and plays an essential role in generating branched actin filament networks during many different cellular processes. In mammals, however, the ARPC1 and ARPC5 subunits are each encoded by two isoforms that are 67% identical. This raises the possibility that Arp2/3 complexes with different properties may exist. We found that Arp2/3 complexes containing ARPC1B and ARPC5L are significantly better at promoting actin assembly than those with ARPC1A and ARPC5, both in cells and in vitro. Branched actin networks induced by complexes containing ARPC1B or ARPC5L are also disassembled ∼2-fold slower than those formed by their counterparts. This difference reflects the ability of cortactin to stabilize ARPC1B- and ARPC5L- but not ARPC1A- and ARPC5-containing complexes against coronin-mediated disassembly. Our observations demonstrate that the Arp2/3 complex in higher eukaryotes is actually a family of complexes with different properties.
Arp2/3 复合物由七个进化上保守的亚基（Arp2、Arp3 和 ARPC1-5）组成，在许多不同的细胞过程中生成分支肌动蛋白丝网络中发挥着重要作用。然而，在哺乳动物中，ARPC1 和 ARPC5 亚基分别由两种 67%相同的同工型编码。这就提出了一个可能性，即可能存在具有不同特性的 Arp2/3 复合物。我们发现，含有 ARPC1B 和 ARPC5L 的 Arp2/3 复合物在促进肌动蛋白组装方面明显优于含有 ARPC1A 和 ARPC5 的复合物，无论是在细胞内还是在体外都是如此。由含有 ARPC1B 或 ARPC5L 的复合物诱导的分支肌动蛋白网络的解体速度也比其对应物形成的网络慢约 2 倍。这种差异反映了 cortactin 稳定 ARPC1B 和 ARPC5L 但不能稳定 ARPC1A 和 ARPC5 包含的复合物对抗冠状蛋白介导的解体的能力。我们的观察结果表明，高等真核生物中的 Arp2/3 复合物实际上是一组具有不同特性的复合物。
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