Vacuolar fusion protein CCZ1 homolog

UniProtKB accession:  Q9VZL5

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 (PubMed:23418349, PubMed:32499409). 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).