| Title: | The tyrosine kinase substrate eps15 is constitutively associated with the plasma membrane adaptor AP-2 |
| Author(s): | Benmerah A; Gagnon J; Begue B; Megarbane B; Dautry-Varsat A; Cerf-Bensussan N; |
| Address: | "Developpement Normal et Pathologique du Systeme Immunitaire, INSERM U 429; Hopital Necker-Enfants Malades, Paris, France" |
| ISSN/ISBN: | 0021-9525 (Print) 1540-8140 (Electronic) 0021-9525 (Linking) |
| Abstract: | "The ubiquitous eps15 protein was initially described as a substrate of the EGF receptor kinase. Its functions are not yet delineated and this work provides evidence for its possible role in endocytosis. A novel anti-eps15 antibody, 6G4, coimmunoprecipitated proteins of molecular mass 102 kD. In human cells, these proteins were identified as the alpha- and beta-adaptins of the AP-2 complex on the basis of their NH2-terminal sequence and their immunoreactivity with anti-alpha- and anti-beta-adaptin antibodies but not with anti-gamma-adaptin antibody. In addition, the anti-eps15 antibody coimmunoprecipitated metabolically labeled polypeptides with molecular mass of 50 and 17 kD, comparable to those of the two other components of the AP-2 complex, mu2 and sigma 2. Constitutive association of eps15 with AP-2 was confirmed by two sets of experiments. First, eps15 was detected in immunoprecipitates of anti-alpha- and anti-beta-adaptin antibodies. Second, alpha- and beta- but not gamma-adaptins were precipitated by a glutathione-S-transferase eps15 fusion protein. The association of eps15 with AP-2 was ubiquitous and conserved between species, since it was observed in human lymphocytes and epithelial cells and in murine NIH3T3 fibroblasts. Our results are in keeping with a recent study showing homology between the NH2-terminal domains of eps15 and the product of the gene END3, involved in clathrin-mediated endocytosis of the pheromone alpha factor in Saccharomyces cerevisiae, and suggest a possible role for eps15 in clathrin-mediated endocytosis in mammals" |
| Keywords: | "3T3 Cells/enzymology *Adaptor Protein Complex 1 *Adaptor Protein Complex 2 *Adaptor Protein Complex 3 Adaptor Protein Complex alpha Subunits Adaptor Protein Complex beta Subunits *Adaptor Protein Complex mu Subunits Adaptor Proteins, Signal Transducing Ad;" |
| Notes: | "MedlineBenmerah, A Gagnon, J Begue, B Megarbane, B Dautry-Varsat, A Cerf-Bensussan, N eng Research Support, Non-U.S. Gov't 1995/12/01 J Cell Biol. 1995 Dec; 131(6 Pt 2):1831-8. doi: 10.1083/jcb.131.6.1831" |
