PKCeta is required for beta1gamma2/beta3gamma2- and PKD-mediated transport to the cell surface and the organization of the Golgi apparatus.
Protein kinase D (PKD) binds to a pool of diacylglycerol (DAG) in the TGN and undergoes a process of activation that involves heterotrimeric GTP-binding protein subunits betagamma to regulate membrane fission. This fission reaction is used to generate transport carriers at the TGN that are en route to the cell surface. We now report that PKD is activated specifically by G protein subunit beta1gamma2 and beta3gamma2 via the Golgi apparatus-associated PKCeta. Compromising the kinase activity of PKCeta-inhibited protein transport from TGN to the cell surface. Expression of constitutively activated PKCeta caused Golgi fragmentation, which was inhibited by a kinase inactive form of PKD. Our findings reveal that betagamma, PKCeta, and PKD act in series to generate transport carriers from the TGN and their overactivation results in complete vesiculation of the Golgi apparatus.
Díaz Añel
Alberto Marcelo
AM
Department of Biology, University of California, San Diego, La Jolla, CA 92093, USA.
Malhotra
Vivek
V
D000595:Amino Acid Sequence; D002462:Cell Membrane / Q000201:enzymology* / Q000502:physiology; D002478:Cells, Cultured; D004075:Diglycerides / Q000378:metabolism; D004789:Enzyme Activation; D044387:GTP-Binding Protein beta Subunits / Q000378:metabolism; D006056:Golgi Apparatus / Q000201:enzymology* / Q000502:physiology; D006367:HeLa Cells; D006801:Humans; D008969:Molecular Sequence Data; D010766:Phosphorylation; D011493:Protein Kinase C / Q000378:metabolism*; D021381:Protein Transport
D004075:Diglycerides; D044387:GTP-Binding Protein beta Subunits; C081975:protein kinase C eta; C089212:protein kinase D; D011493:Protein Kinase C