title: The alpha5beta1 integrin selectively enhances epidermal growth factor signaling to the phosphatidylinositol-3-kinase/Akt pathway in intestinal epithelial cells.
abstract: We have investigated EGF-driven signaling processes in rat intestinal epithelial cell lines that overexpress either the alpha5beta1 integrin or the alpha2beta1 integrin. Both cell types display efficient activation of Erk/MAP kinase, but only the alpha5beta1 expressing cells display a strong activation of Akt. A complex is formed between activated EGFR and alpha5beta1, but not with alpha2beta1; this complex also contains ErbB3 and p85. Thus alpha5beta1 can support efficient activation of both the Erk and the phosphatidylinositol-3-kinase/Akt branches of the EGFR signaling cascade, whereas alpha2beta1 can support only the Erk branch.
authors.affiliation: Department of Pharmacology, School of Medicine, University of North Carolina, 1106 Mary Ellen Jones Building, Chapel Hill, NC 27599-7365, USA.
authors.forename: Jung Weon
authors.initials: JW
authors.lastname: Lee
authors.forename: R L
authors.initials: RL
authors.lastname: Juliano
mesh_terms: D048868:Adaptor Proteins, Signal Transducing; D000818:Animals; D002460:Cell Line; D004789:Enzyme Activation; D004815:Epidermal Growth Factor / Q000494:pharmacology*; D004847:Epithelial Cells / Q000378:metabolism; D066246:ErbB Receptors / Q000737:chemistry / Q000378:metabolism; D051380:GRB2 Adaptor Protein; D016023:Integrins / Q000096:biosynthesis; D007413:Intestinal Mucosa / Q000378:metabolism*; D020928:Mitogen-Activated Protein Kinases / Q000378:metabolism; D019869:Phosphatidylinositol 3-Kinases / Q000378:metabolism*; D011233:Precipitin Tests; D017346:Protein Serine-Threonine Kinases; D011506:Proteins / Q000378:metabolism; D011518:Proto-Oncogene Proteins / Q000737:chemistry / Q000378:metabolism; D051057:Proto-Oncogene Proteins c-akt; D051381:Rats; D038981:Receptors, Collagen; D017469:Receptors, Fibronectin / Q000096:biosynthesis* / Q000737:chemistry; D015398:Signal Transduction
chemical_list: D048868:Adaptor Proteins, Signal Transducing; D004815:Epidermal Growth Factor; D066246:ErbB Receptors; D051380:GRB2 Adaptor Protein; D016023:Integrins; D020928:Mitogen-Activated Protein Kinases; D019869:Phosphatidylinositol 3-Kinases; D017346:Protein Serine-Threonine Kinases; D011506:Proteins; D011518:Proto-Oncogene Proteins; D051057:Proto-Oncogene Proteins c-akt; D038981:Receptors, Collagen; D017469:Receptors, Fibronectin; C495950:Grb2 protein, rat; C494920:Akt1 protein, rat