Preferential oxidation of the second phosphatase domain of receptor-like PTP-alpha revealed by an antibody against oxidized protein tyrosine phosphatases.
Protein tyrosine phosphatases (PTPs) constitute a large enzyme family with important biological functions. Inhibition of PTP activity through reversible oxidation of the active-site cysteine residue is emerging as a general, yet poorly characterized, regulatory mechanism. In this study, we describe a generic antibody-based method for detection of oxidation-inactivated PTPs. Previous observations of oxidation of receptor-like PTP (RPTP) alpha after treatment of cells with H(2)O(2) were confirmed. Platelet-derived growth factor (PDGF)-induced oxidation of endogenous SHP-2, sensitive to treatment with the phosphatidylinositol 3-kinase inhibitor LY294002, was demonstrated. Furthermore, oxidation of RPTPalpha was shown after UV-irradiation. Interestingly, the catalytically inactive second PTP domain of RPTPalpha demonstrated higher susceptibility to oxidation. The experiments thus demonstrate previously unrecognized intrinsic differences between PTP domains to susceptibility to oxidation and suggest mechanisms for regulation of RPTPs with tandem PTP domains. The antibody strategy for detection of reversible oxidation is likely to facilitate further studies on regulation of PTPs and might be applicable to analysis of redox regulation of other enzyme families with active-site cysteine residues.
Persson
Camilla
C
Ludwig Institute for Cancer Research, Box 595, SE-751 24 Uppsala, Sweden.
Sjöblom
Tobias
T
Groen
Arnoud
A
Kappert
Kai
K
Engström
Ulla
U
Hellman
Ulf
U
Heldin
Carl-Henrik
CH
den Hertog
Jeroen
J
Ostman
Arne
A
D000478:Alkylation; D000595:Amino Acid Sequence; D000818:Animals; D000906:Antibodies / Q000276:immunology*; D000918:Antibody Specificity; D000077214:Becaplermin; D001665:Binding Sites; D002460:Cell Line; D006801:Humans; D006861:Hydrogen Peroxide / Q000494:pharmacology; D019807:Iodoacetic Acid / Q000494:pharmacology; D051379:Mice; D008969:Molecular Sequence Data; D010084:Oxidation-Reduction / Q000187:drug effects / Q000528:radiation effects; D010982:Platelet-Derived Growth Factor / Q000494:pharmacology; D017434:Protein Structure, Tertiary; D017027:Protein Tyrosine Phosphatases / Q000737:chemistry / Q000276:immunology* / Q000378:metabolism*; D020574:Proto-Oncogene Proteins c-sis; D014466:Ultraviolet Rays; D014638:Vanadates / Q000494:pharmacology
D000906:Antibodies; D010982:Platelet-Derived Growth Factor; D020574:Proto-Oncogene Proteins c-sis; C076715:pervanadate; D000077214:Becaplermin; D014638:Vanadates; D006861:Hydrogen Peroxide; D017027:Protein Tyrosine Phosphatases; D019807:Iodoacetic Acid