Is post-transcriptional stabilization, splicing and translation of selective mRNAs a key to the DNA damage response?

In response to DNA damage, cells activate a complex, kinase-based signaling network that consists of two components-a rapid phosphorylation-driven signaling cascade that results in immediate inhibition of Cdk/cyclin complexes to arrest the cell cycle along with recruitment of repair machinery to damaged DNA, followed by a delayed transcriptional response that promotes cell cycle arrest through the induction of Cdk inhibitors, such as p21. In recent years a third layer of complexity has emerged that involves post-transcriptional control of mRNA stability, splicing and translation as a critical part of the DNA damage response. Here, we describe recent work implicating DNA damage-dependent modification of RNA-binding proteins that are responsible for some of these mRNA effects, highlighting recent work on post-transcriptional regulation of the cell cycle checkpoint protein/apoptosis inducer Gadd45 alpha by the checkpoint kinase MAPKAP Kinase-2.