小鼠胸腺细胞核骨架肌动蛋白的研究

STUDY ON THE NUCLEAR MATRIX ACTIN IN MOUSE THYMOCYTE

以细胞分级抽提结合间接免疫荧光染色法，观察小鼠胸腺细胞核骨架肌动蛋白，结果显示：间期细胞核骨架肌动蛋白遍布全核，Ｆ－肌动蛋白主要分布于核周，构成环层，细胞有丝分裂期间，核骨架肌动蛋白经抽提后依然保留，这与胞质肌动蛋白有明显不同。ＳＤＳ－ＰＡＧＥ及免疫印迹反应结果表明，肌动蛋白是小鼠胸腺细胞核骨架的主要成分之一，双向电泳进一步说明，核骨架肌动蛋白除含有β和γ肌动蛋白外，还含有核骨架所特有的肌动蛋白，其等电点为５．１０。

By using of selective extraction combined with indirect immunofluorescence staining and Western-blotting,we showed that the 43kD protein in nuclear matrix fraction was of actin. Actin is one of the main component of mouse thymocyte nuclear matrix. Two dimensional electrophoresis showed that besides βand γactin,there exists another actin with PI 5. 10. The nuclear matrix actin distributes over whole nucleus in interphase cells. In mitotic cells,the nuclear matrix actin forms a cage around mitotic spindle and assembles in daughter nuclei in late telophase. By using FITC-phalloidin,the agent reacting with F-actin specifically,we observed a F-actin ring in nuclear periphery after slective extraction. We deduced that the nuclear matrix actin may be a framework of nuclear matrix. F-actin may play a role of contraction which may be essential for the function of nuclear matrix.