Burridge K, Nuckolls G, Otey C, Pavalko F, Simon K, Turner C
Department of Cell Biology and Anatomy, University of North Carolina, Chapel Hill 27599-7090.
Cell Differ Dev. 1990 Dec 2;32(3):337-42. doi: 10.1016/0922-3371(90)90048-2.
Focal adhesions are regions of the plasma membrane where cells in tissue culture adhere strongly to the underlying extracellular matrix, and which at their cytoplasmic face serve to anchor bundles of actin microfilaments. They provide an experimental model for studying the links between the cytoskeleton and the extracellular matrix. Members of the integrin family of extracellular matrix receptors are prominent components, spanning the membrane in focal adhesions, but there is evidence that other membrane components are also needed for these structures to form. A number of proteins are concentrated at the cytoplasmic face of focal adhesions. Recent efforts have sought to determine the links between actin and the integrin cytoplasmic domains. Using in vitro binding assays, two potential bridges between actin and integrin have been identified. One involves talin, which has recently been shown to bind actin directly. The other involves the actin-binding protein, alpha-actinin, which has been found to interact with several integrins. The physiological significance of these two potential bridges between actin and integrin remains to be determined in vivo.
粘着斑是细胞膜上的区域，组织培养中的细胞在此处与下方的细胞外基质紧密粘附，并且在其细胞质面用于锚定肌动蛋白微丝束。它们为研究细胞骨架与细胞外基质之间的联系提供了一个实验模型。细胞外基质受体整合素家族的成员是突出的组成部分，在粘着斑中跨膜，但有证据表明这些结构的形成还需要其他膜成分。许多蛋白质集中在粘着斑的细胞质面。最近的研究致力于确定肌动蛋白与整合素细胞质结构域之间的联系。通过体外结合试验，已鉴定出肌动蛋白与整合素之间的两种潜在桥梁。一种涉及踝蛋白，最近已证明它可直接结合肌动蛋白。另一种涉及肌动蛋白结合蛋白α-辅肌动蛋白，已发现它可与几种整合素相互作用。这两种肌动蛋白与整合素之间潜在桥梁的生理意义仍有待在体内确定。
