Src kinase regulates the integrity and function of the Golgi apparatus via activation of dynamin 2.
The size and integrity of the Golgi apparatus is maintained via a tightly controlled regulation of membrane traffic using a variety of different signaling and cytoskeletal proteins. We have recently observed that activation of c-Src has profound effects on Golgi structure, leading to dramatically vesiculated cisternae in a variety of cell types. As the large GTPase dynamin (Dyn2) has been implicated in Golgi vesiculation during secretion, we tested whether inhibiting Dyn2 activity by expression of a Dyn2K44A mutant or siRNA knockdown could attenuate active Src-induced Golgi fragmentation. Indeed, these perturbations attenuated fragmentation, and expression of a Dyn2Y(231/597)F mutant protein that cannot be phosphorylated by Src kinase had a similar effect . Finally, we find that Dyn2 is markedly phosphorylated during the transit of VSV-G protein through the TGN whereas expression of the Dyn2Y(231/597)F mutant significantly reduces exit of the nascent protein from this compartment. These findings demonstrate that activation of Dyn2 by Src kinase regulates Golgi integrity and vesiculation during the secretory process.
Department of Biochemistry and Molecular Biology and the Miles and Shirley Fiterman Center for Digestive Diseases, Mayo Clinic, Rochester, MN, 55905, USA.
Shaun G
SG
Weller
Mirco
M
Capitani
Hong
H
Cao
Massimo
M
Micaroni
Alberto
A
Luini
Michele
M
Sallese
Mark A
MA
McNiven
D019943:Amino Acid Substitution; D000818:Animals; D045744:Cell Line, Tumor; D002478:Cells, Cultured; D006224:Cricetinae; D034285:Dynamin II / Q000037:antagonists & inhibitors / Q000235:genetics / Q000378:metabolism*; D006056:Golgi Apparatus / Q000378:metabolism*; D006367:HeLa Cells; D006801:Humans; D008562:Membrane Glycoproteins / Q000235:genetics / Q000378:metabolism; D016297:Mutagenesis, Site-Directed; D010190:Pancreatic Neoplasms / Q000235:genetics / Q000378:metabolism / Q000473:pathology; D010641:Phenotype; D010766:Phosphorylation; D034741:RNA, Small Interfering / Q000235:genetics; D051381:Rats; D011994:Recombinant Proteins / Q000235:genetics / Q000378:metabolism; D014162:Transfection; D014759:Viral Envelope Proteins / Q000235:genetics / Q000378:metabolism; D019061:src-Family Kinases / Q000378:metabolism*; D021601:trans-Golgi Network / Q000378:metabolism
C028391:G protein, vesicular stomatitis virus; D008562:Membrane Glycoproteins; D034741:RNA, Small Interfering; D011994:Recombinant Proteins; D014759:Viral Envelope Proteins; D019061:src-Family Kinases; D034285:Dynamin II