title: Activation of the protein tyrosine phosphatase SHP2 via the interleukin-6 signal transducing receptor protein gp130 requires tyrosine kinase Jak1 and limits acute-phase protein expression.
abstract: Stimulation of the interleukin-6 (IL-6) signalling pathway occurs via the IL-6 receptor-glycoprotein 130 (IL-6R-gp130) receptor complex and results in the regulation of acute-phase protein genes in liver cells. Ligand binding to the receptor complex leads to tyrosine phosphorylation and activation of Janus kinases (Jak), phosphorylation of the signal transducing subunit gp130, followed by recruitment and phosphorylation of the signal transducer and activator of transcription factors STAT3 and STAT1 and the src homology domain (SH2)-containing protein tyrosine phosphatase (SHP2). The tyrosine phosphorylated STAT factors dissociate from the receptor, dimerize and translocate to the nucleus where they bind to enhancer sequences of IL-6 target genes. Phosphorylated SHP2 is able to bind growth factor receptor bound protein (grb2) and thus might link the Jak/STAT pathway to the ras/raf/mitogen-activated protein kinase pathway. Here we present data on the dose-dependence, kinetics and kinase requirements for SHP2 phosphorylation after the activation of the signal transducer, gp130, of the IL-6-type family receptor complex. When human fibrosarcoma cell lines deficient in Jak1, Jak2 or tyrosine kinase 2 (Tyk2) were stimulated with IL-6-soluble IL-6R complexes it was found that only in Jak1-, but not in Jak 2- or Tyk2-deficient cells, SHP2 activation was greatly impaired. It is concluded that Jak1 is required for the tyrosine phosphorylation of SHP2. This phosphorylation depends on Tyr-759 in the cytoplasmatic domain of gp130, since a Tyr-759-->Phe exchange abrogates SHP2 activation and in turn leads to elevated and prolonged STAT3 and STAT1 activation as well as enhanced acute-phase protein gene induction. Therefore, SHP2 plays an important role in acute-phase gene regulation.
authors.affiliation: Department of Biochemistry, RWTH-Aachen, Pauwelsstrasse 30, D52057 Aachen, Germany.
authors.forename: F
authors.initials: F
authors.lastname: Schaper
authors.forename: C
authors.initials: C
authors.lastname: Gendo
authors.forename: M
authors.initials: M
authors.lastname: Eck
authors.forename: J
authors.initials: J
authors.lastname: Schmitz
authors.forename: C
authors.initials: C
authors.lastname: Grimm
authors.forename: D
authors.initials: D
authors.lastname: Anhuf
authors.forename: I M
authors.initials: IM
authors.lastname: Kerr
authors.forename: P C
authors.initials: PC
authors.lastname: Heinrich
mesh_terms: D015703:Antigens, CD / Q000737:chemistry / Q000502:physiology*; D006528:Carcinoma, Hepatocellular; D050822:Cytokine Receptor gp130; D004268:DNA-Binding Proteins / Q000378:metabolism; D004789:Enzyme Activation; D006801:Humans; D015850:Interleukin-6 / Q000494:pharmacology / Q000502:physiology*; D047908:Intracellular Signaling Peptides and Proteins; D053613:Janus Kinase 1; D053614:Janus Kinase 2; D008113:Liver Neoplasms; D008562:Membrane Glycoproteins / Q000737:chemistry / Q000502:physiology*; D016297:Mutagenesis, Site-Directed; D054592:Protein Tyrosine Phosphatase, Non-Receptor Type 11; D053824:Protein Tyrosine Phosphatase, Non-Receptor Type 6; D017027:Protein Tyrosine Phosphatases / Q000378:metabolism*; D011505:Protein-Tyrosine Kinases / Q000378:metabolism; D011506:Proteins / Q000378:metabolism; D011518:Proto-Oncogene Proteins; D019947:Receptors, Interleukin-6 / Q000502:physiology; D011993:Recombinant Fusion Proteins / Q000737:chemistry / Q000378:metabolism; D054593:SH2 Domain-Containing Protein Tyrosine Phosphatases; D050796:STAT3 Transcription Factor; D015398:Signal Transduction; D053634:TYK2 Kinase; D015534:Trans-Activators / Q000378:metabolism; D014407:Tumor Cells, Cultured; D018909:src Homology Domains
chemical_list: D015703:Antigens, CD; D004268:DNA-Binding Proteins; C494199:IL6ST protein, human; D015850:Interleukin-6; D047908:Intracellular Signaling Peptides and Proteins; D008562:Membrane Glycoproteins; D011506:Proteins; D011518:Proto-Oncogene Proteins; D019947:Receptors, Interleukin-6; D011993:Recombinant Fusion Proteins; D050796:STAT3 Transcription Factor; C494086:STAT3 protein, human; D015534:Trans-Activators; D050822:Cytokine Receptor gp130; D011505:Protein-Tyrosine Kinases; C507904:JAK1 protein, human; C507924:JAK2 protein, human; D053613:Janus Kinase 1; D053614:Janus Kinase 2; D053634:TYK2 Kinase; C070139:TYK2 protein, human; C516724:PTPN11 protein, human; C509249:PTPN6 protein, human; D054592:Protein Tyrosine Phosphatase, Non-Receptor Type 11; D053824:Protein Tyrosine Phosphatase, Non-Receptor Type 6; D017027:Protein Tyrosine Phosphatases; D054593:SH2 Domain-Containing Protein Tyrosine Phosphatases