RGG-motif self-association regulates eIF4G-binding translation repressor protein Scd6.

Regulation of mRNA translation plays a key role in the control of gene expression. Scd6, a conserved RGG-motif containing protein represses translation by binding to translation initiation factor eIF4G1. Here we report that Scd6 binds itself in RGG-motif dependent manner and self-association regulates its repression activity. Scd6 self-interaction competes with eIF4G1 binding and methylation of Scd6 RGG-motif by Hmt1 negatively affects self-association. Results pertaining to Sbp1 indicate that self-association could be a general feature of RGG-motif containing translation repressor proteins. Taken together, our study reveals a mechanism of regulation of eIF4G-binding RGG-motif translation repressors.