Moraes Karen C M, Wilusz Carol J, Wilusz Jeffrey
Department of Microbiology, Immunology & Pathology, College of Veterinary Medicine & Biomedical Sciences, Colorado State University, Fort Collins, 80523, USA.
RNA. 2006 Jun;12(6):1084-91. doi: 10.1261/rna.59606. Epub 2006 Apr 6.
CUG-BP is the human homolog of the Xenopus EDEN-BP, which was shown previously to bind to mRNAs, such as c-mos, that exhibit rapid deadenylation following fertilization of the oocyte. While several studies have focused on roles of CUG-BP as a splicing or translation regulator in mammalian cells, its role in mRNA decay has not been examined in detail. Here, we have used an in vitro deadenylation assay to dissect the function of CUG-BP in the decay of two ARE-containing mRNAs: c-fos and TNFalpha. CUG-BP binds specifically to both of these RNAs and stimulates poly(A) shortening by PARN. Moreover, CUG-BP interacts with PARN in extracts by coimmunoprecipitation, and this interaction can be recapitulated using recombinant proteins. CUG-BP, therefore, is the first RNA-binding protein shown to directly recruit a deadenylase to an RNA substrate.
CUG-BP是非洲爪蟾EDEN-BP的人类同源物，先前已证明它能与诸如c-mos等mRNA结合，这些mRNA在卵母细胞受精后会迅速发生去腺苷酸化。虽然有几项研究聚焦于CUG-BP在哺乳动物细胞中作为剪接或翻译调节因子的作用，但其在mRNA降解中的作用尚未得到详细研究。在此，我们使用体外去腺苷酸化试验来剖析CUG-BP在两种含ARE的mRNA（c-fos和TNFα）降解中的功能。CUG-BP特异性结合这两种RNA，并通过PARN刺激聚腺苷酸缩短。此外，CUG-BP通过免疫共沉淀与提取物中的PARN相互作用，并且这种相互作用可以用重组蛋白重现。因此，CUG-BP是首个被证明能直接将去腺苷酸酶招募到RNA底物上的RNA结合蛋白。
