Coupling transcription to translation

Recently, we identified a novel function for Ctk1, a known transcription factor. The kinase Ctk1 phosphorylates the C-terminal domain (CTD) of Rpb1, the largest subunit of RNA polymerase II, during transcription elongation. We showed that Ctk1 has a second function in translation, a cytoplasmic step of gene expression. Here, Ctk1 phosphorylates Rps2, a protein of the small ribosomal subunit. This phosphorylation event increases translational fidelity.
Since Ctk1 also interacts with the TREX complex we hypothesize that Ctk1 is recruited to correctly processed and assembled mRNPs in the nucleus, accompanies them to the cytoplasm where it ensures their correct translation. Thus, Ctk1 function could couple steps in gene expression as distant as transcription and translation.