Src regulates Golgi structure and KDEL receptor-dependent retrograde transport to the endoplasmic reticulum.
The tyrosine kinase Src is present on the Golgi membranes. Its role, however, in the overall function and organization of the Golgi apparatus is unclear. We have found that in a cell line called SYF, which lacks the three ubiquitous Src-like kinases (Src, Yes, and Fyn), the organization of the Golgi apparatus is perturbed. The Golgi apparatus is composed of collapsed stacks and bloated cisternae in these cells. Expression of an activated form of Src relocated the KDEL receptor (KDEL-R) from the Golgi apparatus to the endoplasmic reticulum. Other Golgi-specific marker proteins were not affected under these conditions. Because of the specific effect of Src on the location of KDEL-R, we tested whether protein transport between ER and the Golgi apparatus involves Src. Transport of Pseudomonas exotoxin, which is transported to the ER by binding to the KDEL-R is accelerated by inhibition or genetic ablation of Src. Protein transport from ER to the Golgi apparatus however, is unaffected by Src deletion or inhibition. We propose that Src has an appreciable role in the organization of the Golgi apparatus, which may be linked to its involvement in protein transport from the Golgi apparatus to the endoplasmic reticulum.
Bard
Frédéric
F
UCSD Biological Sciences Division, Cell and Developmental Biology Department, University of California-San Diego, La Jolla, CA 92093-0347, USA. fabard@biomail.ucsd.edu
Mazelin
Laetitia
L
Péchoux-Longin
Christine
C
Malhotra
Vivek
V
Jurdic
Pierre
P
D000818:Animals; D002460:Cell Line; D004721:Endoplasmic Reticulum / Q000378:metabolism*; D005098:Exotoxins / Q000493:pharmacokinetics; D006056:Golgi Apparatus / Q000201:enzymology / Q000378:metabolism / Q000648:ultrastructure*; D051379:Mice; D018345:Mice, Knockout; D015688:Oncogene Protein pp60(v-src) / Q000502:physiology; D021381:Protein Transport; D011518:Proto-Oncogene Proteins / Q000502:physiology; D051076:Proto-Oncogene Proteins c-fyn; D051575:Proto-Oncogene Proteins c-yes; D011549:Pseudomonas; D018000:Receptors, Peptide / Q000378:metabolism*; D019061:src-Family Kinases / Q000502:physiology*
D005098:Exotoxins; C064459:KDEL receptor; D011518:Proto-Oncogene Proteins; D018000:Receptors, Peptide; C494960:Fyn protein, mouse; D015688:Oncogene Protein pp60(v-src); D051076:Proto-Oncogene Proteins c-fyn; D051575:Proto-Oncogene Proteins c-yes; C496639:Yes1 protein, mouse; D019061:src-Family Kinases