Essential for formation of P-bodies, cytoplasmic structures that provide storage sites for translationally inactive mRNAs and protect them from degradation (PubMed:16484376, PubMed:17074753, PubMed:29510985). Acts as a repressor of mRNA translation (PubMed:29510985). May play a role in mitotic spindle assembly (PubMed:26339800). Component of a ribonucleoprotein (RNP) complex (By similarity). Interacts with DDX6 (PubMed:31422817, PubMed:29510985, PubMed:31439631). Interacts with EIF4ENIF1/4E-T; promoting EIF4ENIF1/4E-T localization to P-bodies (PubMed:26027925, PubMed:32354837, PubMed:29510985). Interacts (via FFD box) with EDC4 (PubMed:29510985). 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.