**5.4 Translation**

Translation plays a pivotal role in the control of gene expression and is tightly regulated by MAPK pathways that modulate the activity of several components within the translational machinery [81]. In yeast, Hog1 promotes Rck2-mediated attenuation of protein synthesis in response to osmotic stress by phosphorylation of the translation elongation factor 2 (EF-2) [82]. ERK- and p38-activated MNKs phosphorylate the elongation initiation factor eIF4E to enhance translation initiation [83]. Another example is the activation of RSK, a downstream kinase of ERK. RSK phosphorylates S6, a component of the 40S ribosomal subunit, as well as the elongation initiation factor eIF4B, which facilitates their binding to eIF3 to promote mRNA translation [84, 85]. Besides the targeting of newly transcribed mRNAs, translation regulation can also target mRNAs that have not been transcriptionally induced, a type of regulation found in yeast and mammals [86].
