Jurkat细胞增殖过程中S期激酶相关蛋白2与p27^kip1的表达变化及意义

Expression variation and significance of Skp2 and p27^kip1 during the proliferation of Jurkat cells

目的探讨S期激酶相关蛋白2（skp2）与p27^kip1在淋巴瘤细胞株Jurkat细胞增殖过程中的表达变化及意义。方法采用免疫沉淀法检测Jurkat细胞中p27^kip1与Skp2的结合情况；采用血清饥饿合并释放法同步化处理Jurkat细胞，再分别用Western blot技术、免疫荧光双标技术及核浆分离法检测p27^kip1和Skp2在Jurkat细胞中的表达变化及亚细胞定位。结果p27^kip1与Skp2能够相互结合。在Jurkat细胞增殖过程中，p27““蛋白表达减少，其中在细胞核内的减少更明显；Skp2蛋白表达增加，其中在细胞浆中的增加更明显。结论在Jurkat细胞增殖过程中，Skp2在细胞浆中的合成增加，并可能通过加快p27^kip1的泛素化降解使细胞核内p27^kip1显著减少，从而推动细胞周期的进程。

Objective To investigate the expression variation and significance of Skp2 and p27^kip1 during the proliferation of lymphoma cell line Jurkat cells. Methods The binding of p27^kip1and Skp2 in Jurkat cells were detected by immunoprecipitation. Jurkat cells were treated with serum starvation and release synchronization. The expression variation and subcellular localization of p27^kip1 and Skp2 were detected by subcellular fractionation, Western blot and double immunofluorescence labelling. Results The results of immunoprecipitation suggested that p27^kip1 and Skp2 could bind each other in Jurkat cells. During the proliferation of Jurkat cells, the protein expression of p27^kip1 decreased and intranuclear p27kipl decreased significantly, while the Skp2 protein increased and cytoplasmic Skp2 increased significantly. Com^lusion During the proliferation of Jurkat cells, the increased cytoplasmic synthesis of Skp2 may speed up p27^kip1 degradation via the ubiquitin-proteasome pathway, then intranuclear p27^kip1 decreases significantly, leading to an increased cell cycling activity.