Lateral diffusion of lectin receptors in fibroblast membranes as a function of cell shape.
Lateral diffusion of lectin receptors in fibroblast membranes as a function of cell shape.
复制标题
成纤维细胞膜中凝集素受体的横向扩散作为细胞形状的函数。
DOI：
10.1016/0014-4827(89)90078-5
复制
发表时间：
1989
影响因子：
3.7
通讯作者：
Schindler,M
中科院分区：
文献类型：
--
作者：
Swaisgood,M;Schindler,M
锚定依赖性成纤维细胞仅在附着并铺展在合适的基质表面上时才会对生化生长信号做出反应。成纤维细胞的附着启动细胞骨架组装过程，导致长肌动蛋白应力纤维和微管的组织，这可能是跨膜信号转导所必需的。然而，保持悬浮状态的成纤维细胞保持球形，没有明显的应力纤维或长微管。由于形状修饰引起的细胞骨架组织存在显着差异，以及由此导致的膜受体的组织和动力学可能发生的变化，采用光漂白后荧光重分布（FRAP）技术来检查未转化和克尔斯滕鼠肉瘤病毒转化的Balb/c 3T3质膜中麦芽凝集素（WGA）和琥珀酰化伴刀豆球蛋白A（sCon A）受体的侧向迁移性成纤维细胞处于扩散和球形状态。对呈扩散或球形状态的两种细胞系的 FITC-WGA 和 FITC-sCon A 与质膜结合的检查表明，WGA 或 Con A 受体的数量作为形状或转化的函数没有显着差异。这项研究的主要观察结果是 (a) 球形 Balb/c 3T3 成纤维细胞中的膜 WGA 和 sCon A 受体显示的迁移率比扩散状态下快 12 倍，而磷脂迁移率相似且明显与形状无关，(b) 扩散状态下的转化细胞具有与扩散状态下的未转化细胞相似的 WGA 和 sCon A 受体迁移率，(c) 平坦贴壁，但不是独立的球形， Balb/c 3T3 成纤维细胞受到 Con A 诱导的全局调节，并且 (d) 球形状态的转化细胞包含大量细胞 (~30%)，其 WGA 受体迁移率比球形未转化细胞中观察到的更快。这些观察结果是根据膜蛋白扩散的链接矩阵模型进行讨论的。
Anchorage-dependent fibroblasts respond to biochemical growth signals only when attached to and spread on a suitable substrate surface. Attachment of fibroblasts initiates a cytoskeletal assembly process that results in the organization of long actin stress fibers and microtubules which may be required for transmembrane signal transduction. Fibroblasts maintained in suspension, however, remain spherical with no apparent stress fibers or lengthy microtubules. Because of the significant differences in cytoskeletal organisation induced by shape modification, and the resulting possible changes in organization and dynamics of membrane receptors, the technique of fluorescence redistribution after photobleaching (FRAP) was employed to examine the lateral mobility of wheat germ agglutinin (WGA) and succinylated concanavalin A (sCon A) receptors in the plasma membrane of untransformed and Kirsten murine sarcoma virus-transformed Balb/c 3T3 fibroblasts in the spread and spherical state. An examination of FITC-WGA and FITC-sCon A binding to the plasma membrane for both cell lines in a spread or spherical state demonstrated no significant differences in the number of WGA or Con A receptors as a function of shape or transformation. The primary observations from this study are (a) membrane WGA and sCon A receptors in spherical Balb/c 3T3 fibroblasts display mobility 12 times faster than in the spread state, while phospholipid mobility is similar and apparently shape independent, (b) transformed cells in the spread state have WGA and sCon A receptor mobilities similar to those of untransformed cells in the spread state, (c) flat adherent, but not unattached spherical, Balb/c 3T3 fibroblasts are subject to Con A-induced global modulation, and (d) transformed cells in the spherical state contain a significant population of cells (~30%) with WGA receptor mobilities faster than those observed in spherical untransformed cells. These observations are discussed in terms of a linked matrix model for membrane protein diffusion.