title: Site-specific incorporation of a phosphotyrosine mimetic reveals a role for tyrosine phosphorylation of SHP-2 in cell signaling.
abstract: The regulation of protein tyrosine phosphatase (PTPase) SHP-2 is proposed to involve tyrosine phosphorylation on two tail tyrosine residues. Using "expressed protein ligation", nonhydrolyzable phosphotyrosine analogs were introduced at known phosphorylation sites in SHP-2. Biochemical analysis suggests that a phosphonate at Tyr542 interacts intramolecularly with the N-terminal SH2 domain to relieve basal inhibition of the PTPase, whereas a phosphonate at Tyr-580 stimulates the PTPase activity by interaction with the C-terminal SH2 domain. Microinjection experiments indicate that a single phosphorylation of Tyr-542 of SHP-2 is sufficient to activate the MAP kinase pathway in living cells. These studies support a novel mechanism explaining how tyrosine phosphorylation of a PTPase is important in signal transduction.
authors.affiliation: Department of Pharmacology and Molecular Sciences, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA.
authors.forename: W
authors.initials: W
authors.lastname: Lu
authors.forename: D
authors.initials: D
authors.lastname: Gong
authors.forename: D
authors.initials: D
authors.lastname: Bar-Sagi
authors.forename: P A
authors.initials: PA
authors.lastname: Cole
mesh_terms: D048868:Adaptor Proteins, Signal Transducing; D000595:Amino Acid Sequence; D016895:Culture Media, Serum-Free; D004789:Enzyme Activation; D051380:GRB2 Adaptor Protein; D047908:Intracellular Signaling Peptides and Proteins; D008845:Microinjections; D008856:Microscopy, Fluorescence; D008969:Molecular Sequence Data; D015394:Molecular Structure; D010766:Phosphorylation; D019000:Phosphotyrosine / Q000737:chemistry / Q000378:metabolism*; D017354:Point Mutation; D011487:Protein Conformation; D054592:Protein Tyrosine Phosphatase, Non-Receptor Type 11; D053824:Protein Tyrosine Phosphatase, Non-Receptor Type 6; D017027:Protein Tyrosine Phosphatases / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D011506:Proteins / Q000235:genetics / Q000378:metabolism; D011993:Recombinant Fusion Proteins / Q000737:chemistry / Q000378:metabolism; D054593:SH2 Domain-Containing Protein Tyrosine Phosphatases; D015398:Signal Transduction / Q000502:physiology*; D019032:Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization; D020860:Subtilisin / Q000378:metabolism
chemical_list: D048868:Adaptor Proteins, Signal Transducing; D016895:Culture Media, Serum-Free; D051380:GRB2 Adaptor Protein; D047908:Intracellular Signaling Peptides and Proteins; D011506:Proteins; D011993:Recombinant Fusion Proteins; D019000:Phosphotyrosine; 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; D020860:Subtilisin