Direct activation of TACE-mediated ectodomain shedding by p38 MAP kinase regulates EGF receptor-dependent cell proliferation.
Inflammatory stimuli activate ectodomain shedding of TNF-alpha, L-selectin, and other transmembrane proteins. We show that p38 MAP kinase, which is activated in response to inflammatory or stress signals, directly activates TACE, a membrane-associated metalloprotease that is also known as ADAM17 and effects shedding in response to growth factors and Erk MAP kinase activation. p38alpha MAP kinase interacts with the cytoplasmic domain of TACE and phosphorylates it on Thr(735), which is required for TACE-mediated ectodomain shedding. Activation of TACE by p38 MAP kinase results in the release of TGF-alpha family ligands, which activate EGF receptor signaling, leading to enhanced cell proliferation. Conversely, depletion of p38alpha MAP kinase activity suppresses EGF receptor signaling and downstream Erk MAP kinase signaling, as well as autocrine EGF receptor-dependent proliferation. Autocrine EGF receptor activation through TACE-mediated ectodomain shedding intimately links inflammation and cancer progression and may play a role in stress and conditions that relate to p38 MAP kinase activation.
Xu
Pinglong
P
Department of Cell and Tissue Biology, Programs in Cell Biology and Developmental Biology, University of California, San Francisco, San Francisco, CA 94143, USA.
Derynck
Rik
R
D051722:ADAM Proteins / Q000235:genetics / Q000378:metabolism*; D000072198:ADAM17 Protein; D000818:Animals; D002460:Cell Line; D049109:Cell Proliferation; D006224:Cricetinae; D003412:Cricetulus; D004475:Ectoderm / Q000166:cytology* / Q000378:metabolism*; D004789:Enzyme Activation; D066246:ErbB Receptors / Q000378:metabolism*; D006801:Humans; D008024:Ligands; D020935:MAP Kinase Signaling System; D048308:Mitogen-Activated Protein Kinase 14 / Q000235:genetics / Q000378:metabolism*; D019000:Phosphotyrosine / Q000378:metabolism; D017382:Reactive Oxygen Species / Q000378:metabolism; D016211:Transforming Growth Factor alpha / Q000378:metabolism; D048051:p38 Mitogen-Activated Protein Kinases / Q000235:genetics / Q000378:metabolism*
D008024:Ligands; D017382:Reactive Oxygen Species; D016211:Transforming Growth Factor alpha; D019000:Phosphotyrosine; D066246:ErbB Receptors; D048308:Mitogen-Activated Protein Kinase 14; D048051:p38 Mitogen-Activated Protein Kinases; D051722:ADAM Proteins; D000072198:ADAM17 Protein; C000606462:ADAM17 protein, human