Diacylglycerol is required for the formation of COPI vesicles in the Golgi-to-ER transport pathway.
Diacylglycerol is necessary for trans-Golgi network (TGN) to cell surface transport, but its functional relevance in the early secretory pathway is unclear. Although depletion of diacylglycerol did not affect ER-to-Golgi transport, it led to a redistribution of the KDEL receptor to the Golgi, indicating that Golgi-to-ER transport was perturbed. Electron microscopy revealed an accumulation of COPI-coated membrane profiles close to the Golgi cisternae. Electron tomography showed that the majority of these membrane profiles originate from coated buds, indicating a block in membrane fission. Under these conditions the Golgi-associated pool of ARFGAP1 was reduced, but there was no effect on the binding of coatomer or the membrane fission protein CtBP3/BARS to the Golgi. The addition of 1,2-dioctanoyl-sn-glycerol or the diacylglycerol analogue phorbol 12,13-dibutyrate reversed the effects of endogenous diacylglycerol depletion. Our findings implicate diacylglycerol in the retrograde transport of proteins from Golgi to the ER and suggest that it plays a critical role at a late stage of COPI vesicle formation.
Fernández-Ulibarri
Inés
I
Departament de Biologia Cellular i Anatomia Patològica, Facultat de Medicina and Institut d'Investigacions Biomèdiques August Pi i Sunyer, Universitat de Barcelona, 08036 Barcelona, Spain.
Vilella
Montserrat
M
Lázaro-Diéguez
Francisco
F
Sarri
Elisabet
E
Martínez
Susana E
SE
Jiménez
Nuria
N
Claro
Enrique
E
Mérida
Isabel
I
Burger
Koert N J
KN
Egea
Gustavo
G
D000818:Animals; D001692:Biological Transport / Q000187:drug effects; D020126:Brefeldin A / Q000494:pharmacology; D022181:COP-Coated Vesicles / Q000378:metabolism*; D019556:COS Cells; D002352:Carrier Proteins / Q000378:metabolism; D002462:Cell Membrane / Q000187:drug effects / Q000378:metabolism; D002522:Chlorocebus aethiops; D020755:Coat Protein Complex I / Q000378:metabolism*; D004075:Diglycerides / Q000378:metabolism* / Q000494:pharmacology; D004721:Endoplasmic Reticulum / Q000187:drug effects / Q000378:metabolism* / Q000648:ultrastructure; D004963:Estrenes / Q000494:pharmacology; D020690:GTPase-Activating Proteins / Q000378:metabolism; D006056:Golgi Apparatus / Q000187:drug effects / Q000378:metabolism* / Q000648:ultrastructure; D006367:HeLa Cells; D006801:Humans; D015240:Phorbol 12,13-Dibutyrate / Q000494:pharmacology; D011433:Propranolol / Q000494:pharmacology; D011760:Pyrrolidinones / Q000494:pharmacology; D051381:Rats; D018000:Receptors, Peptide / Q000378:metabolism; D015398:Signal Transduction / Q000187:drug effects
D002352:Carrier Proteins; D020755:Coat Protein Complex I; D004075:Diglycerides; D004963:Estrenes; D020690:GTPase-Activating Proteins; C064459:KDEL receptor; D011760:Pyrrolidinones; D018000:Receptors, Peptide; C044295:1,2-dioctanoylglycerol; C060229:1-(6-((3-methoxyestra-1,3,5(10)-trien-17-yl)amino)hexyl)-1H-pyrrole-2,5-dione; D020126:Brefeldin A; D015240:Phorbol 12,13-Dibutyrate; D011433:Propranolol