title: Intrinsically active variants of Erk oncogenically transform cells and disclose unexpected autophosphorylation capability that is independent of TEY phosphorylation.
abstract: The receptor-tyrosine kinase (RTK)/Ras/Raf pathway is an essential cascade for mediating growth factor signaling. It is abnormally overactive in almost all human cancers. The downstream targets of the pathway are members of the extracellular regulated kinases (Erk1/2) family, suggesting that this family is a mediator of the oncogenic capability of the cascade. Although all oncogenic mutations in the pathway result in strong activation of Erks, activating mutations in Erks themselves were not reported in cancers. Here we used spontaneously active Erk variants to check whether Erk's activity per se is sufficient for oncogenic transformation. We show that Erk1(R84S) is an oncoprotein, as NIH3T3 cells that express it form foci in tissue culture plates, colonies in soft agar, and tumors in nude mice. We further show that Erk1(R84S) and Erk2(R65S) are intrinsically active due to an unusual autophosphorylation activity they acquire. They autophosphorylate the activatory TEY motif and also other residues, including the critical residue Thr-207 (in Erk1)/Thr-188 (in Erk2). Strikingly, Erk2(R65S) efficiently autophosphorylates its Thr-188 even when dually mutated in the TEY motif. Thus this study shows that Erk1 can be considered a proto-oncogene and that Erk molecules possess unusual autoregulatory properties, some of them independent of TEY phosphorylation.
authors.affiliation: Department of Biological Chemistry, Institute of Life Science, Hebrew University of Jerusalem, Jerusalem 91904, Israel Department of Microbiology, Yong Loo Lin School of Medicine, National University of Singapore, Singapore 117456.
authors.forename: Karina
authors.initials: K
authors.lastname: Smorodinsky-Atias
authors.affiliation: Department of Biological Chemistry, Institute of Life Science, Hebrew University of Jerusalem, Jerusalem 91904, Israel.
authors.forename: Tal
authors.initials: T
authors.lastname: Goshen-Lago
authors.affiliation: Department of Biological Chemistry, Institute of Life Science, Hebrew University of Jerusalem, Jerusalem 91904, Israel.
authors.forename: Anat
authors.initials: A
authors.lastname: Goldberg-Carp
authors.affiliation: Department of Biology, Technion-Israel Institute of Technology, Haifa 32000, Israel.
authors.forename: Dganit
authors.initials: D
authors.lastname: Melamed
authors.affiliation: Department of Biological Chemistry, Institute of Life Science, Hebrew University of Jerusalem, Jerusalem 91904, Israel.
authors.forename: Alexei
authors.initials: A
authors.lastname: Shir
authors.affiliation: Department of Biological Chemistry, Institute of Life Science, Hebrew University of Jerusalem, Jerusalem 91904, Israel Department of Microbiology, Yong Loo Lin School of Medicine, National University of Singapore, Singapore 117456.
authors.forename: Navit
authors.initials: N
authors.lastname: Mooshayef
authors.affiliation: Department of Biological Chemistry, Institute of Life Science, Hebrew University of Jerusalem, Jerusalem 91904, Israel.
authors.forename: Jonah
authors.initials: J
authors.lastname: Beenstock
authors.affiliation: Department of Biological Chemistry, Institute of Life Science, Hebrew University of Jerusalem, Jerusalem 91904, Israel Wolfson Centre for Applied Structural Biology, Hebrew University of Jerusalem, Jerusalem 91904, Israel.
authors.forename: Yael
authors.initials: Y
authors.lastname: Karamansha
authors.affiliation: Department of Microbiology, Yong Loo Lin School of Medicine, National University of Singapore, Singapore 117456 CREATE-NUS-HUJ, Cellular and Molecular Mechanisms of Inflammation Program, National University of Singapore, Singapore 138602.
authors.forename: Ilona
authors.initials: I
authors.lastname: Darlyuk-Saadon
authors.affiliation: Department of Biological Chemistry, Institute of Life Science, Hebrew University of Jerusalem, Jerusalem 91904, Israel Wolfson Centre for Applied Structural Biology, Hebrew University of Jerusalem, Jerusalem 91904, Israel.
authors.forename: Oded
authors.initials: O
authors.lastname: Livnah
authors.affiliation: Department of Chemistry and Biochemistry, University of Colorado, Boulder, CO 80309.
authors.forename: Natalie G
authors.initials: NG
authors.lastname: Ahn
authors.affiliation: Department of Biology, Technion-Israel Institute of Technology, Haifa 32000, Israel.
authors.forename: Arie
authors.initials: A
authors.lastname: Admon
authors.affiliation: Department of Biological Chemistry, Institute of Life Science, Hebrew University of Jerusalem, Jerusalem 91904, Israel Department of Microbiology, Yong Loo Lin School of Medicine, National University of Singapore, Singapore 117456 CREATE-NUS-HUJ, Cellular and Molecular Mechanisms of Inflammation Program, National University of Singapore, Singapore 138602 CREATE-NUS-HUJ, Cellular and Molecular Mechanisms of Inflammation Program, National University of Singapore, Singapore 138602.
authors.forename: David
authors.initials: D
authors.lastname: Engelberg
mesh_terms: D020816:Amino Acid Motifs; D000818:Animals; D002471:Cell Transformation, Neoplastic / Q000235:genetics / Q000378:metabolism*; D048049:Extracellular Signal-Regulated MAP Kinases / Q000235:genetics* / Q000378:metabolism; D057809:HEK293 Cells; D006801:Humans; D020935:MAP Kinase Signaling System; D051379:Mice; D008819:Mice, Nude; D020125:Mutation, Missense; D041681:NIH 3T3 Cells; D010766:Phosphorylation; D000090063:Proto-Oncogene Mas; D051381:Rats
chemical_list: C000715470:MAS1 protein, human; D000090063:Proto-Oncogene Mas; D048049:Extracellular Signal-Regulated MAP Kinases