PKCδ and ε regulate the morphological integrity of the ER-Golgi intermediate compartment (ERGIC) but not the anterograde and retrograde transports via the Golgi apparatus.
The ER-Golgi intermediate compartment (ERGIC) is an organelle through which cargo proteins pass and are being transferred by either anterograde or retrograde transport between the endoplasmic reticulum (ER) and the Golgi apparatus. We examined the effect of 80 different kinase inhibitors on ERGIC morphology and found that rottlerin, a PKCδ inhibitor, induced the dispersion of the perinuclear ERGIC into punctate structures. Rottlerin also delayed anterograde transport of vesicular stomatitis virus G protein (VSVG) from the ER to the Golgi and retrograde transport of cholera toxin from cell surface to the ER via the Golgi. RNA interference revealed that knockdown of PKCδ or ε resulted in the dispersion of the ERGIC, but unexpectedly did not inhibit VSVG and cholera toxin transport. We also found that rottlerin depolarized the mitochondrial membrane potential, as does carbonylcyanide-p-trifluoromethoxyphenylhydrazone (FCCP), an uncoupler, and demonstrated that a decrease in the intracellular adenosine triphosphate (ATP) levels by rottlerin might underlie the block in transports. These results suggest that PKCδ and ε specifically regulate the morphology of the ERGIC and that the maintenance of ERGIC structure is not necessarily required for anterograde and retrograde transports.
Department of Life Sciences, The University of Tokyo, Tokyo, Japan.
Taichi
T
Sugawara
Daiki
D
Nakatsu
Hiroaki
H
Kii
Nobuhiko
N
Maiya
Atsuhiro
A
Adachi
Akitsugu
A
Yamamoto
Fumi
F
Kano
Masayuki
M
Murata
D000098:Acetophenones / Q000494:pharmacology; D001578:Benzopyrans / Q000494:pharmacology; D001681:Biological Assay; D001692:Biological Transport / Q000187:drug effects; D002259:Carbonyl Cyanide p-Trifluoromethoxyphenylhydrazone / Q000494:pharmacology; D002451:Cell Compartmentation / Q000187:drug effects*; D002772:Cholera Toxin / Q000378:metabolism; D004721:Endoplasmic Reticulum / Q000187:drug effects / Q000378:metabolism* / Q000648:ultrastructure; D020536:Enzyme Activators / Q000494:pharmacology; D055785:Gene Knockdown Techniques; D006056:Golgi Apparatus / Q000187:drug effects / Q000378:metabolism* / Q000648:ultrastructure; D049452:Green Fluorescent Proteins / Q000378:metabolism; D006367:HeLa Cells; D006801:Humans; D008562:Membrane Glycoproteins / Q000378:metabolism; D053078:Membrane Potential, Mitochondrial / Q000187:drug effects; D051745:Protein Kinase C-delta / Q000378:metabolism*; D051744:Protein Kinase C-epsilon / Q000378:metabolism*; D013755:Tetradecanoylphorbol Acetate / Q000494:pharmacology; D014759:Viral Envelope Proteins / Q000378:metabolism
D000098:Acetophenones; D001578:Benzopyrans; D020536:Enzyme Activators; C028391:G protein, vesicular stomatitis virus; D008562:Membrane Glycoproteins; D014759:Viral Envelope Proteins; D049452:Green Fluorescent Proteins; D002259:Carbonyl Cyanide p-Trifluoromethoxyphenylhydrazone; D002772:Cholera Toxin; C085746:rottlerin; C497258:PRKCD protein, human; C497255:PRKCE protein, human; D051745:Protein Kinase C-delta; D051744:Protein Kinase C-epsilon; D013755:Tetradecanoylphorbol Acetate