Franks Tobias M, Lykke-Andersen Jens
Molecular, Cellular, and Developmental Biology, University of Colorado, Boulder, CO 80309, USA.
Mol Cell. 2008 Dec 5;32(5):605-15. doi: 10.1016/j.molcel.2008.11.001.
mRNA decapping is a critical step in eukaryotic cytoplasmic mRNA turnover. Cytoplasmic mRNA decapping is catalyzed by Dcp2 in conjunction with its coactivator Dcp1 and is stimulated by decapping enhancer proteins. mRNAs associated with the decapping machinery can assemble into cytoplasmic mRNP granules called processing bodies (PBs). Evidence suggests that PB-associated mRNPs are translationally repressed and can be degraded or stored for subsequent translation. However, whether mRNP assembly into a PB is important for translational repression, decapping, or decay has remained controversial. Here, we discuss the regulation of decapping machinery recruitment to specific mRNPs and how their assembly into PBs is governed by the relative rates of translational repression, mRNP multimerization, and mRNA decay.
mRNA去帽是真核细胞质mRNA周转中的关键步骤。细胞质mRNA去帽由Dcp2与其共激活因子Dcp1共同催化,并受到去帽增强蛋白的刺激。与去帽机制相关的mRNA可以组装成称为加工小体(PBs)的细胞质mRNP颗粒。有证据表明,与PB相关的mRNP在翻译上受到抑制,并且可以被降解或储存以供后续翻译。然而,mRNP组装成PB对于翻译抑制、去帽或衰变是否重要仍存在争议。在这里,我们讨论了去帽机制招募到特定mRNP的调控,以及它们组装成PB是如何由翻译抑制、mRNP多聚化和mRNA衰变的相对速率所控制的。