Title:
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Actin filaments are involved in the functional coupling of Vo-V1 domains of vacuolar H-ATPase at the Golgi complex
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Author:
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Serra-Peinado, Carla; Sicart Casellas, Adrià; Llopis, Juan; Egea Guri, Gustavo
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Notes:
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We 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. |
Subject(s):
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-Aparell de Golgi -Citosquelet -Proteïnes citosquelètiques -Enzimologia -Homeòstasi -Golgi apparatus -Cytoskeleton -Cytoskeletal proteins -Enzymology -Homeostasis |
Rights:
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(c) American Society for Biochemistry and Molecular Biology, 2016
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Document type:
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Article Article - Published version |
Published by:
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American Society for Biochemistry and Molecular Biology
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