title: Context-specific flow through the MEK/ERK module produces cell- and ligand-specific patterns of ERK single and double phosphorylation.
abstract: The same pathway, such as the mitogen-activated protein kinase (MAPK) pathway, can produce different cellular responses, depending on stimulus or cell type. We examined the phosphorylation dynamics of the MAPK kinase MEK and its targets extracellular signal-regulated kinase 1 and 2 (ERK1/2) in primary hepatocytes and the transformed keratinocyte cell line HaCaT A5 exposed to either hepatocyte growth factor or interleukin-6. By combining quantitative mass spectrometry with dynamic modeling, we elucidated network structures for the reversible threonine and tyrosine phosphorylation of ERK in both cell types. In addition to differences in the phosphorylation and dephosphorylation reactions, the HaCaT network model required two feedback mechanisms, which, as the experimental data suggested, involved the induction of the dual-specificity phosphatase DUSP6 and the scaffold paxillin. We assayed and modeled the accumulation of the double-phosphorylated and active form of ERK1/2, as well as the dynamics of the changes in the monophosphorylated forms of ERK1/2. Modeling the differences in the dynamics of the changes in the distributions of the phosphorylated forms of ERK1/2 suggested that different amounts of MEK activity triggered context-specific responses, with primary hepatocytes favoring the formation of double-phosphorylated ERK1/2 and HaCaT A5 cells that produce both the threonine-phosphorylated and the double-phosphorylated form. These differences in phosphorylation distributions explained the threshold, sensitivity, and saturation of the ERK response. We extended the findings of differential ERK phosphorylation profiles to five additional cultured cell systems and matched liver tumor and normal tissue, which revealed context-specific patterns of the various forms of phosphorylated ERK.
authors.affiliation: Division Systems Biology of Signal Transduction, German Cancer Research Center (DKFZ), Im Neuenheimer Feld 280, 69120 Heidelberg, Germany.
authors.forename: Nao
authors.initials: N
authors.lastname: Iwamoto
authors.affiliation: Division Systems Biology of Signal Transduction, German Cancer Research Center (DKFZ), Im Neuenheimer Feld 280, 69120 Heidelberg, Germany.
authors.forename: Lorenza A
authors.initials: LA
authors.lastname: D'Alessandro
authors.affiliation: Division Systems Biology of Signal Transduction, German Cancer Research Center (DKFZ), Im Neuenheimer Feld 280, 69120 Heidelberg, Germany.
authors.forename: Sofia
authors.initials: S
authors.lastname: Depner
authors.affiliation: Molecular Structure Analysis, German Cancer Research Center (DKFZ), Im Neuenheimer Feld 280, 69120 Heidelberg, Germany.
authors.forename: Bettina
authors.initials: B
authors.lastname: Hahn
authors.affiliation: Division Systems Biology of Signal Transduction, German Cancer Research Center (DKFZ), Im Neuenheimer Feld 280, 69120 Heidelberg, Germany.
authors.forename: Bernhard A
authors.initials: BA
authors.lastname: Kramer
authors.affiliation: Division Systems Biology of Signal Transduction, German Cancer Research Center (DKFZ), Im Neuenheimer Feld 280, 69120 Heidelberg, Germany.
authors.forename: Philippe
authors.initials: P
authors.lastname: Lucarelli
authors.affiliation: Division Systems Biology of Signal Transduction, German Cancer Research Center (DKFZ), Im Neuenheimer Feld 280, 69120 Heidelberg, Germany.
authors.forename: Artyom
authors.initials: A
authors.lastname: Vlasov
authors.affiliation: Division Systems Biology of Signal Transduction, German Cancer Research Center (DKFZ), Im Neuenheimer Feld 280, 69120 Heidelberg, Germany.
authors.forename: Markus
authors.initials: M
authors.lastname: Stepath
authors.affiliation: Division Systems Biology of Signal Transduction, German Cancer Research Center (DKFZ), Im Neuenheimer Feld 280, 69120 Heidelberg, Germany.
authors.forename: Martin E
authors.initials: ME
authors.lastname: Böhm
authors.affiliation: Department of General, Visceral and Transplantation Surgery, Campus Virchow Clinic, Charité-University Medicine Berlin, Augustenburger Platz 1, 13353 Berlin, Germany.
authors.forename: Daniela
authors.initials: D
authors.lastname: Deharde
authors.affiliation: Department of General, Visceral and Transplantation Surgery, Campus Virchow Clinic, Charité-University Medicine Berlin, Augustenburger Platz 1, 13353 Berlin, Germany.
authors.forename: Georg
authors.initials: G
authors.lastname: Damm
authors.affiliation: Department of General, Visceral and Transplantation Surgery, Campus Virchow Clinic, Charité-University Medicine Berlin, Augustenburger Platz 1, 13353 Berlin, Germany.
authors.forename: Daniel
authors.initials: D
authors.lastname: Seehofer
authors.affiliation: Division Systems Biology of Signal Transduction, German Cancer Research Center (DKFZ), Im Neuenheimer Feld 280, 69120 Heidelberg, Germany. Molecular Structure Analysis, German Cancer Research Center (DKFZ), Im Neuenheimer Feld 280, 69120 Heidelberg, Germany.
authors.forename: Wolf D
authors.initials: WD
authors.lastname: Lehmann
authors.affiliation: Division Systems Biology of Signal Transduction, German Cancer Research Center (DKFZ), Im Neuenheimer Feld 280, 69120 Heidelberg, Germany. Translational Lung Research Center (TLRC), Member of the German Center for Lung Research (DZL), 69120 Heidelberg, Germany.
authors.forename: Ursula
authors.initials: U
authors.lastname: Klingmüller
authors.affiliation: Division Systems Biology of Signal Transduction, German Cancer Research Center (DKFZ), Im Neuenheimer Feld 280, 69120 Heidelberg, Germany. m.schilling@dkfz.de.
authors.forename: Marcel
authors.initials: M
authors.lastname: Schilling
mesh_terms: D002461:Cell Line, Transformed; D054642:Dual Specificity Phosphatase 6 / Q000235:genetics / Q000378:metabolism; D006801:Humans; D020930:MAP Kinase Kinase Kinases / Q000235:genetics / Q000378:metabolism*; D020935:MAP Kinase Signaling System / Q000502:physiology*; D019950:Mitogen-Activated Protein Kinase 1 / Q000235:genetics / Q000378:metabolism*; D048052:Mitogen-Activated Protein Kinase 3 / Q000235:genetics / Q000378:metabolism*; D008954:Models, Biological; D010766:Phosphorylation / Q000502:physiology
chemical_list: C535150:MAPK1 protein, human; D019950:Mitogen-Activated Protein Kinase 1; D048052:Mitogen-Activated Protein Kinase 3; D020930:MAP Kinase Kinase Kinases; C517035:DUSP6 protein, human; D054642:Dual Specificity Phosphatase 6