Role of the Novel Gene, HIC-5, that encodes a Zn-finger Protein in Cellular Differentiation.

利用hic-5的正义和反义表达载体检测了编码一种新的锌指蛋白的hic-5基因在细胞分化中的作用。强制表达hic-5正义链不影响肌源性C2C12或成骨细胞RCT-1的分化过程，但反义表达载体的引入抑制了成骨分化，表现为细胞外基质蛋白和碱性磷酸酶的表达减少。这些效应可能是HIC-5通过c-fos基因的结构性表达而激活AP-1的结果。抗HIC-5抗体的免疫细胞化学研究表明，该蛋白定位于正常成纤维细胞的局灶性黏附斑块中，HIC-5与纽蛋白、talin和FAK结合。推测HIC-5蛋白是从细胞表面到细胞核的信号转导通路的守门人。

Roles of the hic-5 gene that encodes a novel Zn-finger protein in cellular differetiation was examined using sense-and antisense-expression vectors for hic-5. Forced expression of sense-strand of hic-5 did not affect the differentiation processes of myogenic C2C12 or osteoblastic RCT-1 cells, but introduction of antisence expression vectors inhibited osteogenic differentiation as revealed by decrease in expression of extracellular matric proteins and alkaline phosphatase. These sffects seemed to be a result of AP-1 activation through constitutive expression of c-fos gene that was caused by the HIC-5.Immunocytochemical studies using specific antiboby against HIC-5 showed that the protein localize in focal adhesion plaques in normal fibroblasts, and the HIC-5 associates with vinculin, talin and FAK.It was speculated that the HIC-5 protein is a gate keeper for signal transduction pathways from cellular surface to nuclei.