Involved in post-transcriptional regulation of gene expression (PubMed:24470144). Promotes mRNA stabilization by bridging poly(A)-binding protein to mRNAs (PubMed:24470144). Forms a complex composed of at least MKT1, PBP1, XAC1 and LSM12 (PubMed:32532821). Forms a complex composed of at least MKT1L, PBP1, XAC1 and LSM12 (PubMed:32532821). Within the complex, interacts with MKT1 (via C-terminus); the interaction is direct (PubMed:24470144, PubMed:32532821). Interacts (via C-terminus) with ZC3H11; the interaction is direct (PubMed:24470144). Localizes to polysomes (PubMed:24470144). Localizes to starvation-induced stress granules but not heat shock-induced stress granules (PubMed:24470144). Expressed in the procyclic and bloodstream forms (at protein level). Belongs to the ataxin-2 family.