货物结合域调节了肌肉蛋白5的结构和活性
Kavitha Thirumurugan1, Takeshi Sakamoto, John A Hammer
1Institute of Molecular and Cellular Biology, and Astbury Centre for Structural Molecular Biology, University of Leeds, Leeds LS2 9JT, UK.
Nature
|July 14, 2006
概括
肌蛋白5是一种运动蛋白质,在没有载荷的情况下保持折叠和不活跃. 它的球状尾部域 (GTDs) 结合了运动域,抑制了行为因子相互作用,直到货物存在.
科学领域:
- 分子生物学分子生物学
- 生物化学 生物化学
- 细胞生物学 细胞生物学
背景情况:
- 肌蛋白5是一种运动蛋白质,负责沿着活性纤维进行货物运输.
- 假设Myosin 5的球状尾部域 (GTD) 可以调节货物结合.
- 肌蛋白5活性由水平调节,低促进折叠状态,高促进展开和激活.
研究的目的:
- 为了阐明折叠的髓蛋白的结构5.
- 确定GTDs在调节Myosin 5活性中的作用.
- 了解在没有货物的情况下,肌酸蛋白5自抑制的机制.
主要方法:
- 使用电子显微镜可视化折叠的Myosin 5的结构.
- 生物化学测定使用Myosin 5重型美罗米 (HMM) 和GST-GTD融合蛋白进行.
- 进行了运动性测试,以评估Myosin 5在actin纤维上的运动.
主要成果:
- 电子显微镜显示,折叠的Myosin 5的头通过与运动领域的离子相互作用与GTDs接触.
- 一个二极体GST-GTD融合蛋白抑制并诱导了Myosin 5 HMM中的折叠.
- 在纳米级中,Myosin 5 HMM表现出强大的运动,而Myosin 5表现出弱结合和最小的运动.
结论:
- 在没有载荷的情况下,Myosin 5的GTDs会与其运动领域内分子结合,形成一个抑制的,紧的结构.
- 这种自抑制状态导致弱的活性蛋白结合,促进蛋白质的循环利用以后的货物运输.
- 水平通过影响GTD和运动领域之间的相互作用来调节Myosin 5活性.
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