过表达TRIM69抑制细胞内源c-Jun蛋白的表达

Over expression of TRIM69 inhibits the expression of endogenous c-Jun

目的探索TRIM69负调控AP1信号通路及抑制内源c-Jun蛋白表达的分子机制。方法在子宫颈癌细胞He La细胞或人胚肾细胞HEK293T细胞共转染荧光素酶报告基因质粒和空载体或TRIM69,共转空载体组作为对照,通过双荧光素酶报告基因实验检测了TRIM69对8条关键信号通路的影响;在HEK293T细胞过表达TRIM69全长及各个结构域的截短体,通过Western blot实验检测了TRIM69抑制细胞内源c-Jun蛋白表达的关键结构域;在HEK293T细胞过表达TRIM69,利用cycloheximide(CHX)、MG132或chloroquine分别处理细胞,通过蛋白稳定性实验探讨了TRIM69负调控内源c-Jun蛋白表达的分子机制。结果 TRIM69可以特异负调控AP1信号通路(P<0.05),并且TRIM69对内源c-Jun蛋白表达的抑制作用依赖于其RBCC结构域(P<0.05),进一步研究发现TRIM69通过蛋白酶体途径影响内源c-Jun蛋白的稳定性(P<0.05)。结论 TRIM69负调控AP1信号通路并通过蛋白酶体途径影响内源c-Jun蛋白的降解。

Objective To explore the mechanism of TRIM69 inhibiting AP1 pathway and down regulating the expression of c-Jun. Methods Co-transfect luciferase reporter plasmids and empty vector or TRIM69 plasmid in He La cells or HEK293 T cells and use the empty vector group as control,dual-luciferase reporter assay system was used to check the effect of TRIM69 on eight important pathways; over express all length or the deletion mutants of TRIM69 in HEK293 T cells and western blot was used to examine the key domain which inhibits the expression of c-Jun; over express TRIM69 in HEK293 T cells and then cells were treated with cycloheximide（ CHX）,MG132 or chloroquine,CHX-chase assay was used to investigate the mechanism of TRIM69 down regulates theexpression of c-Jun. Results TRIM69 inhibited AP1 pathway and down regulated the expression of c-Jun which was dependent on its RBCC domain（ P〈0. 05）. TRIM69 negatively regulated the expression of c-Jun through proteasome degradation（ P〈0. 05）. Conclusions TRIM69 down regulates AP1 pathway and inhibits the expression of c-Jun through a proteasome pathway.