FIGURE 8.

Proposed model for the participation of Rck/p54 to translational repression and mRNA decay. Translational repression is initiated by the specific binding of protein X and its partners, including Rck/p54 (the exact stoichiometry of the repressor complex is not represented here). This triggers the sequence-independent binding of Rck/p54 along the mRNA. RNA relaxing is then favored by the presence of ATP. These extended mRNP complexes are then recruited to P-bodies, giving rise to the Rck/p54-rich fibers observed in electron microscopy. They can either return to translation if Rck/p54 is released, or the Rck/p54 located close to the 5′ cap can recruit the decapping complex, leading to mRNA degradation.