The ear of alpha-adaptin interacts with the COOH-terminal domain of the Eps 15 protein.
The role of Eps15 in clathrin-mediated endocytosis is supported by two observations. First, it interacts specifically and constitutively with the plasma membrane adaptor AP-2. Second, its NH2 terminus shows significant homology to the NH2 terminus of yeast End3p, necessary for endocytosis of alpha-factor. To gain further insight into the role of Eps15-AP-2 association, we have now delineated their sites of interactions. AP-2 binds to a domain of 72 amino acids (767-739) present in the COOH terminus of Eps15. This domain contains 4 of the 15 DPF repeats characteristic of the COOH-terminal domain of Eps15 and shares no homology with known proteins, including the related Epsl5r protein. Precipitation of proteolytic fragments of AP-2 with Eps15-derived fusion proteins containing the binding site for AP-2 showed that Eps15 binds specifically to a 40-kDa fragment corresponding to the ear of alpha-adaptin, a result confirmed by precipitation of Eps15 by alpha-adaptin-derived fusion proteins. Our data indicate that this specific part of AP-2 binds to a cellular component and provide the tools for investigating the functions of the association between AP-2 and Eps15.
Benmerah
A
A
Développement Normal et Pathologique de Système Immunitaire, INSERM U429, Paris, France.
Bégue
B
B
Dautry-Varsat
A
A
Cerf-Bensussan
N
N
D033965:Adaptor Protein Complex alpha Subunits; D048868:Adaptor Proteins, Signal Transducing; D033942:Adaptor Proteins, Vesicular Transport; D001665:Binding Sites; D002135:Calcium-Binding Proteins / Q000378:metabolism*; D004268:DNA-Binding Proteins / Q000378:metabolism*; D005982:Glutathione Transferase / Q000378:metabolism; D006801:Humans; D047908:Intracellular Signaling Peptides and Proteins; D008565:Membrane Proteins / Q000737:chemistry / Q000378:metabolism*; D010750:Phosphoproteins / Q000378:metabolism*; D011993:Recombinant Fusion Proteins / Q000378:metabolism; D015398:Signal Transduction; D050656:Transcription Factor AP-2; D014157:Transcription Factors / Q000378:metabolism*
D033965:Adaptor Protein Complex alpha Subunits; D048868:Adaptor Proteins, Signal Transducing; D033942:Adaptor Proteins, Vesicular Transport; D002135:Calcium-Binding Proteins; D004268:DNA-Binding Proteins; C486206:EPS15 protein, human; D047908:Intracellular Signaling Peptides and Proteins; D008565:Membrane Proteins; D010750:Phosphoproteins; D011993:Recombinant Fusion Proteins; D050656:Transcription Factor AP-2; D014157:Transcription Factors; D005982:Glutathione Transferase