期刊名称：Proceedings of the National Academy of Sciences
印刷版ISSN：0027-8424
电子版ISSN：1091-6490
出版年度：2009
卷号：106
期号：15
页码：6203-6208
DOI：10.1073/pnas.0812425106
语种：English
出版社：The National Academy of Sciences of the United States of America
摘要：RBX1 (RING box protein-1) or ROC1 (regulator of cullins-1) is the RING component of SCF (Skp1, Cullins, F-box proteins) E3 ubiquitin ligases, which regulate diverse cellular processes by targeting various substrates for degradation. However, the in vivo physiological function of RBX1 remains uncharacterized. Here, we show that a gene trap disruption of mouse Rbx1 causes embryonic lethality at embryonic day (E)7.5, mainly due to a failure in proliferation; p27, a cyclin dependent kinase inhibitor, normally undetectable in the early embryos, accumulates at high levels in the absence of Rbx1. Although mice heterozygous for the Rbx1 gene trap appear viable and fertile without obvious abnormalities, the Rbx1+/Gt MEFs do show retarded growth with G1 arrest and p27 accumulation. Simultaneous loss of p27 extended the life span of Rbx1Gt/Gt embryos from E6.5 to E9.5, indicating that p27-mediated cell cycle inhibition contributes to the early embryonic lethality in the Rbx1-deficient embryos. Our study demonstrates that the in vivo physiological function of RBX1 is to ensure cell proliferation by preventing p27 accumulation during the early stage of embryonic development.
关键词：SCF E3 ubiquitin ligase ; protein degradation ; growth suppression
