Serra-Peinado, CarlaSicart Casellas, AdriàLlopis, JuanEgea Guri, Gustavo2017-02-162017-02-162016-02-120021-9258https://hdl.handle.net/2445/107063We previously reported that actin-depolymerizing agents promote the alkalization of the Golgi stack and thetrans-Golgi network. The main determinant of acidic pH at the Golgi is the vacuolar-type H(+)-translocating ATPase (V-ATPase), whose V1domain subunitsBandCbind actin. We have generated a GFP-tagged subunitB2construct (GFP-B2) that is incorporated into the V1domain, which in turn is coupled to the V0sector. GFP-B2 subunit is enriched at distal Golgi compartments in HeLa cells. Subcellular fractionation, immunoprecipitation, and inversal FRAP experiments show that the actin depolymerization promotes the dissociation of V1-V0domains, which entails subunitB2translocation from Golgi membranes to the cytosol. Moreover, molecular interaction between subunitsB2andC1and actin were detected. In addition, Golgi membrane lipid order disruption byd-ceramide-C6 causes Golgi pH alkalization. We conclude that actin regulates the Golgi pH homeostasis maintaining the coupling of V1-V0domains of V-ATPase through the binding of microfilaments to subunitsBandCand preserving the integrity of detergent-resistant membrane organization. These results establish the Golgi-associated V-ATPase activity as the molecular link between actin and the Golgi pH.14 p.application/pdfeng(c) American Society for Biochemistry and Molecular Biology, 2016Aparell de GolgiCitosqueletProteïnes citosquelètiquesEnzimologiaHomeòstasiGolgi apparatusCytoskeletonCytoskeletal proteinsEnzymologyHomeostasisinfo:eu-repo/semantics/article6582822017-02-16info:eu-repo/semantics/openAccess26872971