Cell cycle arrest and reversion of Ras-induced transformation by a conditionally activated form of mitogen-activated protein kinase kinase kinase 3.
Signal-induced proliferation, differentiation, or stress responses of cells depend on mitogen-activated protein kinase (MAPK) cascades, the core modules of which consist of members of three successively acting kinase families (MAPK kinase kinase [MAP3K], MAPK kinase, and MAPK). It is demonstrated here that the MEKK3 kinase inhibits cell proliferation, a biologic response not commonly associated with members of the MAP3K family of kinases. A conditionally activated form of MEKK3 stably expressed in fibroblasts arrests these cells in early G1. MEKK3 critically blocks mitogen-driven expression of cyclin D1, a cyclin which is essential for progression of fibroblasts through G1. The MEKK3-induced block of cyclin D1 expression and of cell cycle progression may be mediated via p38 MAPK, a downstream effector of MEKK3. The MEKK3-mediated block of proliferation also reverses Ras-induced cellular transformation, suggesting possible tumor-suppressing functions for this kinase. Together, these results suggest an involvement of the MEKK3 kinase in negative regulation of cell cycle progression, and they provide the first insights into biologic activities of this kinase.
Ellinger-Ziegelbauer
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Laboratory of Immunoregulation, National Institutes of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, Maryland 20892-1876, USA.
Kelly
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Siebenlist
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D016475:3T3 Cells; D000818:Animals; D017209:Apoptosis / Q000235:genetics*; D017871:Calcium-Calmodulin-Dependent Protein Kinases / Q000235:genetics; D002453:Cell Cycle / Q000235:genetics*; D002455:Cell Division / Q000235:genetics; D019938:Cyclin D1 / Q000235:genetics; D018844:Cyclin-Dependent Kinases / Q000235:genetics; D004789:Enzyme Activation; D005455:Fluorescent Antibody Technique; D016193:G1 Phase / Q000235:genetics; D005786:Gene Expression Regulation; D011905:Genes, ras / Q000235:genetics*; D048371:MAP Kinase Kinase 3; D020930:MAP Kinase Kinase Kinases; D051379:Mice; D020929:Mitogen-Activated Protein Kinase Kinases; D020928:Mitogen-Activated Protein Kinases; D017346:Protein Serine-Threonine Kinases / Q000235:genetics*; D011505:Protein-Tyrosine Kinases / Q000235:genetics; D014170:Transformation, Genetic; D048051:p38 Mitogen-Activated Protein Kinases
D019938:Cyclin D1; D011505:Protein-Tyrosine Kinases; D017346:Protein Serine-Threonine Kinases; D017871:Calcium-Calmodulin-Dependent Protein Kinases; D018844:Cyclin-Dependent Kinases; D020928:Mitogen-Activated Protein Kinases; D048051:p38 Mitogen-Activated Protein Kinases; D020930:MAP Kinase Kinase Kinases; D048371:MAP Kinase Kinase 3; C482531:Map2k3 protein, mouse; D020929:Mitogen-Activated Protein Kinase Kinases