The phosphatidylinositol 4-kinase PI4KIIIalpha is required for the recruitment of GBF1 to Golgi membranes
| Autor: | Santiago Costantino, Salima Akam, Stephane Lefrancois, Karine Dumaresq-Doiron, Marie-France Savard |
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| Rok vydání: | 2010 |
| Předmět: |
Golgi Apparatus
Biology symbols.namesake chemistry.chemical_compound Phosphatidylinositol Phosphates Chlorocebus aethiops Animals Guanine Nucleotide Exchange Factors Humans Phosphatidylinositol Enzyme Inhibitors 1-Phosphatidylinositol 4-Kinase Kinase Endoplasmic reticulum Vesicle RAB1 Cell Biology Intracellular Membranes Golgi apparatus Cell biology Isoenzymes rab1 GTP-Binding Proteins Cytosol chemistry COS Cells symbols ADP-Ribosylation Factor 1 RNA Interference Guanine nucleotide exchange factor HeLa Cells |
| Zdroj: | Journal of cell science. 123(Pt 13) |
| ISSN: | 1477-9137 |
| Popis: | Sorting from the Golgi apparatus requires the recruitment of cytosolic coat proteins to package cargo into trafficking vesicles. An important early step in the formation of trafficking vesicles is the activation of Arf1 by the guanine nucleotide exchange factor GBF1. To activate Arf1, GBF1 must be recruited to and bound to Golgi membranes, a process that requires Rab1b. However, the mechanistic details of how Rab1 is implicated in GBF1 recruitment are not known. In this study, we demonstrate that the recruitment of GBF1 also requires phosphatidylinositol 4-phosphate [PtdIns(4)P]. Inhibitors of PtdIns(4)P synthesis or depletion of PI4KIIIα, a phosphatidylinositol 4-kinase localized to the endoplasmic reticulum and Golgi, prevents the recruitment of GBF1 to Golgi membranes. Interestingly, transfection of dominant-active Rab1 increased the amount of PtdIns(4)P at the Golgi, as detected by GFP-PH, a PtdIns(4)P-sensing probe. We propose that Rab1 contributes to the specificity and timing of GBF1 recruitment by activating PI4KIIIα. The PtdIns(4)P produced then allows GBF1 to bind to Golgi membranes and activate Arf1. |
| Databáze: | OpenAIRE |
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