在Arp2/3复合体上,Las17结合的两个位点对于S. cerevisiae中功能性内细胞活性蛋白网络的分支核和组装都很重要
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In Vitro Polymerization of F-actin on Early Endosomes
Published on: August 28, 2017
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Heidy Y Narvaez-Ortiz1, Michael J Lynch1, Su-Ling Liu1
1Department of Chemistry and Biochemistry, Institute of Molecular Biology, University of Oregon, Eugene, Oregon, USA.
The Journal of biological chemistry
|February 17, 2024
概括
在Arp2/3复合体上,这两个结合点对于WASP蛋白的最大激活至关重要,影响着actin网络的形成和细胞过程,如酵母细胞内细胞形成.
科学领域:
- 细胞生物学 细胞生物学
- 生物化学 生物化学
- 分子生物学分子生物学
背景情况:
- Arp2/3复合体对于核化分支性亚丁丝是必不可少的,驱动关键的细胞过程,如内细胞分裂和乳突起.
- Arp2/3复合体的激活主要由与特定部位结合的WASP家族蛋白质进行介导,但每个部位的功能意义仍然不完全理解.
研究的目的:
- 为了研究WASP蛋白 Las17在芽酵母中Arp2/3复合物的激活和功能中的两个不同的结合点的作用.
- 确定影响Las17参与的突变如何影响这些部位的Actin网络的组装和力产生.
主要方法:
- 使用局部定向突变生成来制造酵母Arp2/3复杂突变体,在特定的部位具有受损的Las17结合.
- 在体外生化测试被用来评估Arp2/3复合体激活和actin核化.
- 采用珠子运动性试验来评估由野生型和突变Arp2/3复合体组装的actin网络的产生力能力.
- 在体内进行了对actin丝组织和内细胞位点功能的分析.
主要成果:
- 针对Arp2/3复合体上两个Las17结合位点中的任何一个的突变减少了其在体外最大激活.
- 这两种结合位是必要的,以实现Arp2/3复合物的最佳功能,在产生力作用的活性蛋白网络组合中,如珠子运动性受损所证明的那样.
- 虽然突变的Arp2/3复合体仍然可以在内细胞部位组装actin丝,但它们表现出显著的内化缺陷,表明适当的血膜重塑失败.
- 拉斯17的二元化可以部分挽救任何结合部位有缺陷的突变物的活性.
结论:
- 在Arp2/3复合体上,Las17结合的两个位点都对组装功能性,产生力作用的活性蛋白网络至关重要,这些网络对于发芽酵母的高效内细胞形成是必不可少的.
- 尽管活性降低,但Arp2/3复合物保留了一些体外和体内功能,即使在Las17结合部位之一严重缺陷.
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