Vacuolar fusion protein MON1 homolog

UniProtKB accession:  Q9VR38

Grouped By:  Matching UniProtKB accession

UniProtKB description:  Part of the Mon1-Ccz1 guanyl-nucleotide exchange factor complex specific for Rab7 that promotes the exchange of GDP to GTP, converting Rab7 from an inactive GDP-bound form into an active GTP-bound form (Probable). Plays an important role in membrane trafficking through the secretory apparatus (By similarity). Required for recruitment of Rab7 to endosomal and autophagosomal membranes to mediate endolysosomal and autolysosomal vesicle maturation (PubMed:23418349, PubMed:27559127, PubMed:37463208). Required for fusion of multivesicular bodies and lysosomes but not their formation or trafficking (PubMed:23418349). Involved in the replacement of Rab5 (and possibly Rab4) with Rab7, also known as Rab conversion or the Rab cascade, during endosomal maturation (PubMed:23418349). The Mon1-Ccz1 complex is recruited to phosphatidylinositol 3-phosphate (PtdIns[3]P) enriched membranes by Rab5, which stimulates recruitment and guanyl-nucleotide exchange of Rab7 (PubMed:32391792). Together with Rab7 required for autolysosome formation in fat cells and autophagic degradation during starvation-induced basal and developmental autophagy (PubMed:27559127). Involved in neuromuscular junction (NMJ) presynaptic bouton function and morphogenesis (PubMed:32658990). Together with Rab7, regulates levels of postsynaptic glutamate receptor GluRIIA in the NMJ presynapse (PubMed:32658990).