ROUS-SARCOMA VIRUS-TRANSFORMED FIBROBLASTS ADHERE PRIMARILY AT DISCRETE PROTRUSIONS OF THE VENTRAL MEMBRANE CALLED PODOSOMES
ROUS-SARCOMA VIRUS-TRANSFORMED FIBROBLASTS ADHERE PRIMARILY AT DISCRETE PROTRUSIONS OF THE VENTRAL MEMBRANE CALLED PODOSOMES
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DOI：
10.1016/s0014-4827(85)80044-6
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发表时间：
1985-01-01
影响因子：
3.7
通讯作者：
MARCHISIO, PC
中科院分区：
文献类型：
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作者：
TARONE, G;CIRILLO, D;MARCHISIO, PC
劳斯肉瘤病毒转化的BHK细胞（RSV/B4-BHK）主要在特定的点状部位粘附在纤连蛋白包被的基质上。这些网站包含肌动蛋白和黏着斑蛋白，并代表与基层的密切接触，如干涉反射显微镜所示。与未转化的亲本成纤维细胞相比，在这些细胞中只能检测到少数粘附斑和肌动蛋白丝束。在用透射电子显微镜（TEM）检查的薄切片中，这些粘附部位对应于腹侧细胞表面的短突起，其在其顶端部分接触基质。这些结构，可能代表细胞足，因此被称为podosomes。通过筛选一些不同的转化成纤维细胞铺在纤连蛋白包被的基质上，我们发现，足状体是共同的哺乳动物和鸟类细胞系转化劳斯肉瘤病毒（RSV）或藤波禽肉瘤病毒（FSV），其癌基因编码特定的酪氨酸激酶。使用抗体与磷酸酪氨酸在免疫荧光实验中，我们表明，磷酸酪氨酸含有分子集中在podosomes。在由其他逆转录病毒（Snyder-Theilen肉瘤病毒、Abelson白血病病毒和Kirsten肉瘤病毒）或DNA肿瘤病毒（多瘤病毒，SV 40）转化的成纤维细胞中未检测到足状体，表明转化成纤维细胞中足状体介导的粘附与某些癌蛋白的特殊性质有关，可能与它们对粘附系统的向性有关。虽然在细胞骨架蛋白组成方面相似，但足体和粘附斑具有不同的形成机制和动力学。事实上，足体的组装（i）不需要粘附介质中的胎牛血清（FCS），这是组织粘附斑所必需的;（ii）不需要蛋白质合成;和（iii）对防止粘附斑形成的离子载体莫能菌素不敏感。此外，在连接到纤连蛋白包被的盘子，podosomes出现在初始阶段（60分钟）的附件，而粘附斑块需要至少180分钟。总之，podosomes的RSV和FSV转化的成纤维细胞的粘附结构的表型变体。
Rous sarcoma virus-transformed BHK cells (RSV/B4-BHK) adhere to a fibronectin-coated substratum primarily at specific dot-shaped sites. Such sites contain actin and vinculin and represent close contacts with the substratum as revealed by interference reflection microscopy. Only a few adhesion plaques and actin filament bundles can be detected in these cells as compared to untransformed parental fibroblasts. In thin sections examined with transmission electron microscopy (TEM) these adhesion sites correspond to short protrusions of the ventral cell surface that contact the substratum at their apical portion. These structures, which may represent cellular feet, are therefore called podosomes. By screening a number of different transformed fibroblasts plated on a fibronectin-coated substratum we find that podosomes are common to mammalian and avian cell lines transformed either by Rous sarcoma virus (RSV) or by Fujinami avian sarcoma virus (FSV), whose oncogenes encode specific tyrosine kinases. Using antibodies reacting with phosphotyrosine in immunofluorescence experiments, we show that phosphotyrosine-containing molecules are concentrated in podosomes. Podosomes are not detected in fibroblasts transformed by other retroviruses (Snyder-Theilen sarcoma virus, Abelson leukemia virus and Kirsten sarcoma virus) or by DNA tumor viruses (polyoma, SV40), indicating that podosome-mediated adhesion in transformed fibroblasts is related to the peculiar properties of some oncoproteins and possibly to their tropism for adhesion systems. Podosomes and adhesion plaques, although similar in cytoskeletal protein composition,m have different mechanisms and kinetics of formation. Assembly of podosomes, in fact (i) does not require fetal calf serum (FCS) in the adhesion medium, that is necessary for the organization of adhesion plaques; (ii) does not require protein synthesis; and (iii) is insensitive to the ionophore monensin, that prevents adhesion plaque formation. Moreover, during attachment to fibronectin-coated dishes, podosomes appear in the initial phase (60 min) of attachment, while adhesion plaques require a minimum of 180 min. In conclusion podosomes of RSV- and FSV-transformed fibroblasts represent a phenotypic variant of adhesion structures.