人体纤维素素细胞结合域的位点导向突变发生:可分离的,协同作用的位点介导着粘合功能
M Obara1, M S Kang, K M Yamada
1Membrane Biochemistry Section, National Cancer Institute, Bethesda, Maryland 20892.
Cell
|May 20, 1988
概括
人类纤维肌菌素的人类纤维肌菌素
科学领域:
- 分子生物学分子生物学
- 细胞生物学 细胞生物学
- 生物化学 生物化学
背景情况:
- 纤维蛋白是一种关键的细胞外基质蛋白,参与细胞粘附和迁移.
- 纤维内克的细胞结合域调解与细胞表面受体的相互作用.
- 了解纤维素内功能区域是解读细胞矩阵相互作用的关键.
研究的目的:
- 识别和描述人体纤维菌素细胞结合域的功能必不可少的多序列.
- 研究细胞结合域内的不同功能位点之间的合作和协同相互作用.
- 阐明这些部位在纤维细胞粘附和细胞内反应中的作用.
主要方法:
- 使用局部导向的突变发生,在纤维内蛋白序列中产生特定的缺失和点突变.
- 功能分析涉及评估工程纤维素结合蛋白在大肠杆菌中表达的粘合活性.
- 转补试验和对actin微纤维束组织的分析被用来评估蛋白质功能.
主要成果:
- 删除Arg-Gly-Asp-Ser序列或Asp-to-Glu突变导致粘合活性降低≥97%.
- 确定了位于0.5kb外的第二个功能部位,其突变导致≥96%的活性丧失.
- 突变体在跨补充试验中表现出协同活性,这两个部位对actin组织至关重要.
结论:
- 纤维细胞粘附和由纤维内素细胞结合域介导的细胞内反应依赖于两个不同的协同作用位点.
- 每个已识别的部位都在纤维素菌素的功能中发挥了定量显著的作用.
- 这些发现突出了纤维内素细胞结合域内的功能部位的合作性.
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