RNA-binding protein involved in the formation of polar-growing hyphae which is essential for infection by the plant pathogen (PubMed:15643068). Component of endosomal mRNA transport that regulates polarity of the infectious hyphae by transporting a broad spectrum of cargo mRNAs from the nucleus to cell poles (PubMed:19494833, PubMed:25985087, PubMed:31338952). Part of large ribonucleoprotein complexes (mRNPs) containing RNA-binding proteins RRM4 and PAB1, endosome-binding protein UPA1, core scaffold protein UPA2 and associated factor GRP1 (PubMed:25985087, PubMed:31338952). Interacts (via PABC domain) with UPA1 (via PAM2 domain) (PubMed:25985087). Interacts (via PABC domain) with UPA2 (via PAM2 domains) (PubMed:31338952). Shuttles with endosomes along microtubules. The C-terminal PABC domain is involved in the interaction with UPA1 and UPA2. Belongs to the polyadenylate-binding protein type-1 family.