Eps15 mediates vesicle trafficking from the trans-Golgi network via an interaction with the clathrin adaptor AP-1.
Eps15 (EGFR pathway substrate clone 15) is well known for its role in clathrin-coated vesicle formation at the plasma membrane through interactions with other clathrin adaptor proteins such as AP-2. Interestingly, we observed that in addition to its plasma membrane localization, Eps15 is also present at the trans-Golgi network (TGN). Therefore, we predicted that Eps15 might associate with clathrin adaptor proteins at the TGN and thereby mediate the formation of Golgi-derived vesicles. Indeed, we have found that Eps15 and the TGN clathrin adaptor AP-1 coimmunoprecipitate from rat liver Golgi fractions. Furthermore, we have identified a 14-amino acid motif near the AP-2-binding domain of Eps15 that is required for binding to AP-1, but not AP-2. Disruption of the Eps15-AP-1 interaction via siRNA knockdown of AP-1 or expression of mutant Eps15 protein, which lacks a 14-amino acid motif representing the AP-1 binding site of Eps15, significantly reduced the exit of secretory proteins from the TGN. Together, these findings indicate that Eps15 plays an important role in clathrin-coated vesicle formation not only at the plasma membrane but also at the TGN during the secretory process.
Mayo Clinic College of Medicine, Department of Biochemistry and Molecular Biology, and the Miles and Shirley Fiterman Center for Digestive Diseases, Rochester, MN 55905, USA.
Susan
S
Chi
Hong
H
Cao
Jing
J
Chen
Mark A
MA
McNiven
D048868:Adaptor Proteins, Signal Transducing; D020816:Amino Acid Motifs; D000818:Animals; D002135:Calcium-Binding Proteins / Q000378:metabolism*; D002462:Cell Membrane / Q000378:metabolism; D002966:Clathrin / Q000378:metabolism*; D006224:Cricetinae; D003412:Cricetulus; D004705:Endocytosis; D006056:Golgi Apparatus / Q000378:metabolism; D006367:HeLa Cells; D006801:Humans; D047908:Intracellular Signaling Peptides and Proteins / Q000378:metabolism*; D008099:Liver / Q000378:metabolism; D008954:Models, Biological; D010750:Phosphoproteins / Q000378:metabolism*; D051381:Rats; D018808:Transcription Factor AP-1 / Q000378:metabolism*; D021601:trans-Golgi Network / Q000378:metabolism*
D048868:Adaptor Proteins, Signal Transducing; D002135:Calcium-Binding Proteins; D002966:Clathrin; C486206:EPS15 protein, human; D047908:Intracellular Signaling Peptides and Proteins; D010750:Phosphoproteins; D018808:Transcription Factor AP-1