Activator of decapping that functions as a general and active mechanism of translational repression and required for P-body formation. Stabilizes the 3' terminus of mRNAs and modulates the rates of mRNA-decapping that occur following deadenylation. Might be required for promoting the formation or the stabilization of the preinitiation translation complexes. Necessary for accurate chromosome transmission during cell division (By similarity). Belongs to the PAT1 family.