FYVE zinc finger domain protein that functions in endosomal targeting and transport of mRNAs, as well as associated ribosomes (PubMed:25985087, PubMed:28422978). The endosomal mRNA transport regulates polarity of the infectious hyphae by transporting a broad spectrum of cargo mRNAs from the nucleus to cell poles (PubMed:25985087). Involved in chitinase CTS1 secretion (PubMed:25985087). Dispensable for general endosomal functions but crucial for endosomal recruitment of RRM4 (PubMed:25985087). 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). Interacts (via PAM2 motif) with PAB1 (via PABC domain) (PubMed:25985087). Interacts (via PAM2L motifs) with RRM4 (PubMed:25985087). Shuttles with endosomes along microtubules (PubMed:25985087). the FYVE domain mediates endosomal localization and endosomal targeting is crucial for its function during polar growth and CTS1 secretion (PubMed:25985087). The FYVE domain is sufficient for endosome interaction. The PAM2 motif interacts specifically with the PABC domain of PAB1, wheareas the 2 PAM2L motifs are involved in the interaction with RRM4. Causes defects in hyphal growth and secretion of chitinase CTS1, 2 cellular processes that are regulated by RRM4-mediated endosomal mRNA transport. Belongs to the UPA1 PAM2 domain-binding protein family.