title: Nitrosative/oxidative stress conditions regulate thioredoxin-interacting protein (TXNIP) expression and thioredoxin-1 (TRX-1) nuclear localization.
abstract: Thioredoxin (TRX-1) is a multifunctional protein that controls the redox status of other proteins. TRX-1 can be found in the extracellular milieu, cytoplasm and nucleus, and it has distinct functions in each environment. Previously, we studied the intracellular localization of TRX-1 and its relationship with the activation of the p21Ras-ERK1/2 MAP Kinases signaling pathway. In situations where this pathway was activated by stress conditions evoked by a nitrosothiol, S-nitroso-N-acetylpenicillamine (SNAP), TRX-1 accumulated in the nuclear compartment due to nitrosylation of p21Ras and activation of downstream ERK1/2 MAP kinases. Presently, we demonstrate that ERK1/2 MAP Kinases activation and spatial distribution within cells trigger TRX-1 nuclear translocation through down-regulation of the physiological inhibitor of TRX-1, Thioredoxin Interacting Protein (TXNIP). Once activated by the oxidants, SNAP and H₂O₂, the ERK1/2 MAP kinases migrate to the nucleus. This is correlated with down-regulation of TXNIP. In the presence of the MEK inhibitors (PD98059 or UO126), or in cells transfected with the Protein Enriched in Astrocytes (PEA-15), a cytoplasmic anchor of ERK1/2 MAP kinases, TRX-1 nuclear migration and TXNIP down-regulation are no longer observed in cells exposed to oxidants. On the other hand, over-expression of TXNIP abolishes nuclear migration of TRX-1 under nitrosative/oxidative stress conditions, whereas gene silencing of TXNIP facilitates nuclear migration even in the absence of stress conditions. Studies based on the TXNIP promoter support this regulation. In conclusion, changes in TRX-1 compartmentalization under nitrosative/oxidative stress conditions are dependent on the expression levels of TXNIP, which are regulated by cellular compartmentalization and activation of the ERK1/2 MAP kinases.
authors.affiliation: Departamento de Bioquímica/Biologia Molecular and Center for Cellular and Molecular Therapy - CTCMol - Universidade Federal de São Paulo, São Paulo, Brazil.
authors.forename: Fernando Toshio
authors.initials: FT
authors.lastname: Ogata
authors.affiliation: Departamento de Ciências Biológicas, Universidade Federal de São Paulo, Campus Diadema, São Paulo, Brazil.
authors.forename: Wagner Luiz
authors.initials: WL
authors.lastname: Batista
authors.affiliation: Departamento de Bioquímica/Biologia Molecular and Center for Cellular and Molecular Therapy - CTCMol - Universidade Federal de São Paulo, São Paulo, Brazil.
authors.forename: Adriano
authors.initials: A
authors.lastname: Sartori
authors.affiliation: Departamento de Bioquímica/Biologia Molecular and Center for Cellular and Molecular Therapy - CTCMol - Universidade Federal de São Paulo, São Paulo, Brazil.
authors.forename: Tarsis Ferreira
authors.initials: TF
authors.lastname: Gesteira
authors.affiliation: Department of Biological Responses, Kyoto University, Kyoto, Japan.
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Masutani
authors.affiliation: Department of Pharmacology, New York University School of Medicine, New York, New York, United States of America.
authors.forename: Roberto Jun
authors.initials: RJ
authors.lastname: Arai
authors.affiliation: Department of Biological Responses, Kyoto University, Kyoto, Japan.
authors.forename: Junji
authors.initials: J
authors.lastname: Yodoi
authors.affiliation: Department of Pharmacology, New York University School of Medicine, New York, New York, United States of America.
authors.forename: Arnold
authors.initials: A
authors.lastname: Stern
authors.affiliation: Departamento de Bioquímica/Biologia Molecular and Center for Cellular and Molecular Therapy - CTCMol - Universidade Federal de São Paulo, São Paulo, Brazil.
authors.forename: Hugo Pequeno
authors.initials: HP
authors.lastname: Monteiro
mesh_terms: D000704:Analysis of Variance; D015153:Blotting, Western; D002352:Carrier Proteins / Q000378:metabolism*; D002374:Catalase / Q000378:metabolism; D002467:Cell Nucleus / Q000378:metabolism*; D017931:DNA Primers / Q000235:genetics; D019084:Fluorescent Antibody Technique, Indirect; D005786:Gene Expression Regulation / Q000502:physiology*; D005822:Genetic Vectors / Q000235:genetics; D005979:Glutathione Peroxidase / Q000378:metabolism; D006367:HeLa Cells; D006801:Humans; D018613:Microscopy, Confocal; D018384:Oxidative Stress / Q000502:physiology*; D034741:RNA, Small Interfering / Q000235:genetics; D060888:Real-Time Polymerase Chain Reaction; D013879:Thioredoxins / Q000378:metabolism*; D059008:Time-Lapse Imaging
chemical_list: D002352:Carrier Proteins; D017931:DNA Primers; D034741:RNA, Small Interfering; C491203:TXN protein, human; C486715:TXNIP protein, human; D013879:Thioredoxins; D002374:Catalase; D005979:Glutathione Peroxidase