Gudkova D. The investigation of interaction between CoA synthase and RCD-8, a scaffold protein of processing bodies

In this study we describe a novel binding partner of CoAsy. It is RCD-8 - enhancer of mRNA-decapping protein 4 and the scaffold protein of processing bodies (PBs). Exploration of functional link between CoAsy and RCD-8 revealed a strong inhibition of dephospho-CoA kinase activity of CoAsy by RCD-8 in vitro. We assayed it using two different approaches (a measurement of ATP level after the reaction and a detection of CoA production). Our data clearly show a significance of properly folded RCD-8 protein for the inhibition. In brief, we speculate that the scaffold protein of PBs can modulate CoAsy activity and have the impact on regulation of total CoA level in cells, thus potentially representing a novel mechanism of CoA metabolism control. For the first time a regulation of rate-limiting enzyme in CoA biosynthesis pathway by protein, which is not involved in energetic metabolism, is reported. Key words: CoA synthase, CoA biosynthesis, Р-bodies, mitochondria.