Regulation of repp86 stability by human Siah2
- 作者：Monika Szczepanowski ; Sabine Adam-Klages ; Marie-Luise Kruse ; Marc Pollmann ; Wolfram Klapper ; Reza Parwaresch ; Hans-Juergen Heidebrecht
- 关键词：Repp86 ; Human Siah2 ; Protein degradation
- 刊名：Biochemical and Biophysical Research Communications
- 出版年：2007
- 期刊代码：159_0006291x
- 类别：bio
- 出版时间：19 October 2007
- 卷：362
- 期：2
- 页码：485-490
- 文件大小：523 K
摘要
Human repp86 is a nuclear protein that is expressed in a tightly limited period of time during the cell cycle and plays an essential role in its progression. Manipulation of repp86 expression by reduction of endogenous repp86 or overexpression of exogenous repp86 results in cell cycle arrest. We found that repp86 interacts with human Siah2, which is a known mediator for proteasomal degradation. Siah2 failed to interact with repp86 lacking the first 67 N-terminal amino acids. Overexpression of Siah2 reduced endogenous and exogenous repp86 at the protein level without affecting its mRNA, as shown by cotransfection and RT-PCR experiments. Furthermore, MG-132—a specific inhibitor of the proteasome—blocked the degradation of repp86 in Siah2 overexpressing cells. Moreover, transiently transfected Siah2 abrogated the mitotic arrest in repp86 overexpressing cells. Our data show that Siah2 is an important mediator of repp86 protein degradation.