Kinase signaling initiates coat complex II (COPII) recruitment and export from the mammalian endoplasmic reticulum.
The events regulating coat complex II (COPII) vesicle formation involved in the export of cargo from the endoplasmic reticulum (ER) are unknown. COPII recruitment to membranes is initiated by the activation of the small GTPase Sar1. We have utilized purified COPII components in both membrane recruitment and cargo export assays to analyze the possible role of kinase regulation in ER export. We now demonstrate that Sar1 recruitment to membranes requires ATP. We find that the serine/threonine kinase inhibitor H89 abolishes membrane recruitment of Sar1, thereby preventing COPII polymerization by interfering with the recruitment of the cytosolic Sec23/24 COPII coat complex. Inhibition of COPII recruitment prevents export of cargo from the ER. These results demonstrate that ER export and initiation of COPII vesicle formation in mammalian cells is under kinase regulation.
Aridor
M
M
Departments of Cell and Molecular Biology and the Institute for Childhood and Neglected Diseases, The Scripps Research Institute, La Jolla, California 92037, USA.
Balch
W E
WE
D000255:Adenosine Triphosphate / Q000235:genetics / Q000378:metabolism; D000818:Animals; D022181:COP-Coated Vesicles / Q000378:metabolism*; D004721:Endoplasmic Reticulum / Q000187:drug effects / Q000201:enzymology / Q000378:metabolism*; D004789:Enzyme Activation / Q000187:drug effects; D005656:Fungal Proteins / Q000378:metabolism; D020690:GTPase-Activating Proteins; D007546:Isoquinolines / Q000494:pharmacology; D020559:Monomeric GTP-Binding Proteins / Q000378:metabolism*; D047428:Protein Kinase Inhibitors; D011494:Protein Kinases / Q000378:metabolism*; D021381:Protein Transport / Q000187:drug effects; D051381:Rats; D029701:Saccharomyces cerevisiae Proteins; D015398:Signal Transduction / Q000187:drug effects; D013449:Sulfonamides; D033921:Vesicular Transport Proteins
D005656:Fungal Proteins; D020690:GTPase-Activating Proteins; D007546:Isoquinolines; D047428:Protein Kinase Inhibitors; C079037:SEC23 protein, S cerevisiae; D029701:Saccharomyces cerevisiae Proteins; D013449:Sulfonamides; D033921:Vesicular Transport Proteins; D000255:Adenosine Triphosphate; D011494:Protein Kinases; D020559:Monomeric GTP-Binding Proteins; C077395:SAR1 protein, S cerevisiae; C063509:N-(2-(4-bromocinnamylamino)ethyl)-5-isoquinolinesulfonamide