INVESTIGADORES
PODEROSO Juan Jose
congresos y reuniones científicas
Título:
Cell growth is synchronized by oxidation of specific cysteines of MAPKs in mitochondria.
Autor/es:
ANTICO ARCIUCH, VG; GALLI, S; PODEROSO, C; CONVERSO, DP; CARRERAS, MC; PODEROSO, J J.
Lugar:
Montevideo, Uruguay
Reunión:
Congreso; V Meeting of SFRBM- South American Group. V International Conference on Peroxynitrite and Reactive Nitrogen Species.; 2007
Institución organizadora:
SFRBM- South American Group
Resumen:
By increasing H2O2 yield as a continuum, mitochondria determine cell fate, and predispose to proliferation, arrest, senescence or apoptosis. The aim of this work was to study H2O2 modulation of MAPKs traffic in connection with cell cycle progression of tumor cell line LP07. Subcellular distribution of ERK1/2, p38 and JNK1/2 (nuclei, mitochondria and cytosol) was followed by western blot. Mitochondrial MAPKs localization was assessed by confocal microscopy. Proliferation and apoptosis were evaluated by [H3]thymidine incorporation, flow cytometry with propidium iodide and Annexin V staining. In vitro phosphorylation assays were carried out immunoprecipitating MAPKs and using myelin basic protein and ATF-2 as substrates. We showed herein that endogenous or transfected MAPKs meet a constitutive pool of upstream MAPKKs in mitochondria. We demonstrated that exposure to H2O2 promotes differential activation of the MAPKs in the organelle and controls the passage to nucleus and the proliferation rate. Sequential activation of proliferation by ERK1/2 or cell arrest by p38-JNK1/2 (low to high H2O2) were based upon selective oxidation of conserved cysteine domains to protein sulfinic and sulfonic acids, which adjusts electrostatic binding to respective MAPKKs and contributes to docking specificity. Accordingly, ERK2 C38A and C214A, but not C214E mutations impeded binding to MEK1/2, retained ERK in mitochondria and restricted shuttle to nucleus. The results suggest that reduced H2O2 yield disrupts the synchronized oxidation of MAPKs in proliferating cancer cells.