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.
Chi
Susan
S
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.
Cao
Hong
H
Chen
Jing
J
McNiven
Mark A
MA
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