Abstract
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.
Publication types
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Research Support, Non-U.S. Gov't
MeSH terms
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Animals
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Biological Transport / drug effects
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Brefeldin A / pharmacology
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COP-Coated Vesicles / metabolism*
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COS Cells
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Carrier Proteins / metabolism
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Cell Membrane / drug effects
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Cell Membrane / metabolism
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Chlorocebus aethiops
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Coat Protein Complex I / metabolism*
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Diglycerides / metabolism*
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Diglycerides / pharmacology
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Endoplasmic Reticulum / drug effects
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Endoplasmic Reticulum / metabolism*
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Endoplasmic Reticulum / ultrastructure
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Estrenes / pharmacology
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GTPase-Activating Proteins / metabolism
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Golgi Apparatus / drug effects
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Golgi Apparatus / metabolism*
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Golgi Apparatus / ultrastructure
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HeLa Cells
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Humans
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Phorbol 12,13-Dibutyrate / pharmacology
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Propranolol / pharmacology
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Pyrrolidinones / pharmacology
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Rats
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Receptors, Peptide / metabolism
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Signal Transduction / drug effects
Substances
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Carrier Proteins
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Coat Protein Complex I
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Diglycerides
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Estrenes
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GTPase-Activating Proteins
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KDEL receptor
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Pyrrolidinones
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Receptors, Peptide
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1,2-dioctanoylglycerol
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1-(6-((3-methoxyestra-1,3,5(10)-trien-17-yl)amino)hexyl)-1H-pyrrole-2,5-dione
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Brefeldin A
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Phorbol 12,13-Dibutyrate
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Propranolol