Essential for formation of P-bodies, cytoplasmic structures that provide storage sites for translationally inactive mRNAs and protect them from degradation. Acts as a repressor of mRNA translation. May play a role in mitotic spindle assembly. Component of a ribonucleoprotein (RNP) complex (By similarity). Interacts with DDX6. Interacts with EIF4ENIF1/4E-T; promoting EIF4ENIF1/4E-T localization to P-bodies. Interacts (via FFD box) with EDC4 (By similarity). The LSM14 domain and the RGG repeats are required for accumulation in P-bodies, and the region containing the FDF motif is responsible for cytoplasmic retention. Belongs to the LSM14 family.