Involved in pre-mRNA polyadenylation (PubMed:15121841, PubMed:9819425). May act to repress the ability of PAB1 to negatively regulate polyadenylation (PubMed:9819425). Negative regulator of poly(A) nuclease (PAN) activity (PubMed:15121841). Promotes mating-type switching in mother cells by positively regulating HO mRNA translation (PubMed:15082763). Localizes MKT1 to polysomes (PubMed:15082763). Interacts (via C-terminus) with MKT1 (via C-terminus) (PubMed:15082763). Interacts with FIR1, IGO1, LSM12, PBP4 and PAB1 (PubMed:15121841, PubMed:16702403, PubMed:20471941, PubMed:9819425). Localizes to polysomes. Abnormal mRNA processing; 3' termini are cleaved but transcripts lack full-length poly(A) tails (PubMed:9819425). Decreases HO mRNA translation (PubMed:15082763). Present with 2870 molecules/cell in log phase SD medium. Belongs to the ataxin-2 family.