Ceramide Accumulation Uncovers a Cycling Pathway for the cis-Golgi Network Marker, Infectious Bronchitis Virus M Protein
| Autor: | Carolyn E. Machamer, Michael Maceyka |
|---|---|
| Jazyk: | angličtina |
| Rok vydání: | 1997 |
| Předmět: |
Ceramide
animal structures Membrane lipids Morpholines Infectious bronchitis virus Golgi Apparatus Biology Ceramides Endoplasmic Reticulum Kidney Models Biological Article Cell Line Viral Matrix Proteins symbols.namesake chemistry.chemical_compound Cricetinae Animals Cis-Golgi network Enzyme Inhibitors Sphingolipids Endoplasmic reticulum Cell Biology Golgi apparatus Sphingolipid Cell biology Transmembrane domain Kinetics Biochemistry chemistry symbols Sphingomyelin Biomarkers |
| Zdroj: | The Journal of Cell Biology |
| ISSN: | 1540-8140 0021-9525 |
| Popis: | The M glycoprotein from the avian coronavirus, infectious bronchitis virus (IBV), contains information for localization to the cis-Golgi network in its first transmembrane domain. We hypothesize that localization to the Golgi complex may depend in part on specific interactions between protein transmembrane domains and membrane lipids. Because the site of sphingolipid synthesis overlaps the localization of IBV M, we asked whether perturbation of sphingolipids affected localization of IBV M. Short-term treatment with two inhibitors of sphingolipid synthesis had no effect on localization of IBV M or other Golgi markers. Thus, ongoing synthesis of these lipids was not required for proper localization. Surprisingly, a third inhibitor, d,l-threo-1-phenyl-2-decanoylamino-3-morpholino- 1-propanol (PDMP), shifted the steady-state distribution of IBV M from the Golgi complex to the ER. This effect was rapid and reversible and was also observed for ERGIC-53 but not for Golgi stack proteins. At the concentration of PDMP used, conversion of ceramide into both glucosylceramide and sphingomyelin was inhibited. Pretreatment with upstream inhibitors partially reversed the effects of PDMP, suggesting that ceramide accumulation mediates the PDMP-induced alterations. Indeed, an increase in cellular ceramide was measured in PDMP-treated cells. We propose that IBV M is at least in part localized by retrieval mechanisms. Further, ceramide accumulation reveals this cycle by upsetting the balance of anterograde and retrograde traffic and/ or disrupting retention by altering bilayer dynamics. |
| Databáze: | OpenAIRE |
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