Regulation of cellular growth and differentiation by novel kinase like proteins, TRB family

新型激酶样蛋白 TRB 家族对细胞生长和分化的调节

基本信息

批准号：
18590067
负责人：
HAYASHI Hidetoshi
金额：
$ 2.57万
依托单位：
Nagoya City University
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research (C)
财政年份：
2006
资助国家：
日本
起止时间：
2006 至 2007
项目状态：
已结题

来源：
https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-18590067/
关键词：
TRB3 cell cycle CDC25A protein degradation adipocyte PPARγ PPARγ TRB1 DNA傷害

项目摘要

We recently found that a novel pseudokinase TRB3 was induced by endoplasmic reticulum (ER) stress and regulated the ER stress-inducible apoptosis. It was recently reported that TRB3 was highly expressed in some kind of cancers. Then we examined the function of TRB3 in the cell proliferation from the viewpoint of the cell cycle. The expression level of ectopic CDC25A, one of the cell cycle associated phosphatases, was down-regulated by TRB3 in HeLa cells. On the other hand, endogenous CDC25A level was increased when TRB3 was knockdowned by using the RNAi method. We have observed that TRB3 expressed in a cell cycle dependent manner and this expression pattern was reversely correlated with that of CDC25A at the G2/M phase. When we examined the effect of TRB3 knockdown on the cell cycle, its progression was delayed at the G2/M phase and the down-regulation of CDC25A at the M/G1 phase was significantly suppressed. These results suggest that TRB3 is a modulator of cell cycle progression at t … More he G2/M phase and that the inhibition of CDC25A expression will be one of the targets of TRB3.Next, the influence on the cell differentiation was examined. When we had examined the expression level of the endogenous TRB3 in the adipocyte differentiation process using a mouse preadipocyte cell line, 3T3-L1 cell, its expression have temporarily decreased at the early stage, and then have gradually increased according to the cell differentiation at mRNA and protein level. This expression profile was closely related to the appearance of the stress-inducible transcription factor CHOP10/gadd153. When TRB3 was over-expressed in 3T3-L1 cells, the gross amount of intracellular triglyceride and the mRNA expression level of the downstream targets of PPARγ, which is one of the mastering regulator of adipocyte differentiation. On the other hand, when TRB3 mRNA level was impaired by shRNA method, the adipocyte differentiation was potently obstructed. Moreover, TRB3 and PPARγ were associated each other in the cells, and the adipocyte differentiation induced by PPARγ overexpression was strongly suppressed by the ectopic expression of TRB3. It was shown that TRB3 regulates the adipocyte differentiation by negatively controlling the transcriptional activity of PPARγ. Less

我们最近发现一种新型假激酶TRB3是由内质网应激诱导的，并调节ER应激诱导的细胞凋亡。最近有报道称TRB3在某些癌症中高表达，然后我们检查了TRB3在内质网应激中的功能。从细胞周期的角度来看，异位CDC25A（一种细胞周期相关磷酸酶）的表达水平在HeLa细胞中被TRB3下调。另一方面，当使用RNAi方法敲低TRB3时，内源CDC25A水平增加，我们观察到TRB3以细胞周期依赖性方式表达，并且这种表达模式与G2/M期的CDC25A的表达模式呈负相关。当我们检查 TRB3 敲低对细胞周期的影响时，其进展在 G2/M 期被延迟，并且 CDC25A 在 M/G1 期的下调被显着抑制。 TRB3 是 G2/M 期细胞周期进展的调节剂，并且抑制 CDC25A 表达将是 TRB3 的目标之一。接下来，我们检查了对细胞分化的影响。使用小鼠前脂肪细胞系3T3-L1细胞，在脂肪细胞分化过程中内源TRB3的表达水平，其表达在早期暂时降低，然后根据细胞分化程度逐渐升高。该表达谱与应激诱导转录因子CHOP10/gadd153在3T3-L1细胞中过表达时的出现、细胞内甘油三酯的总量及其mRNA表达水平密切相关。 PPARγ 是脂肪细胞分化的主要调节因子之一，其下游靶标是脂肪细胞分化的主要调节因子之一。此外，TRB3 和 PPARγ 在细胞中相互密切相关，并且 TRB3 的异位表达抑制了 PPARγ 过表达诱导的脂肪细胞分化。。较少的