Tumor protein 53-induced nuclear protein 1 is a major mediator of p53 antioxidant function.

p53 exerts its tumor suppressor function mainly through transcriptional induction of target genes involved in several processes, including cell cycle checkpoints, apoptosis, and regulation of cell redox status. p53 antioxidant function is dependent on its transcriptional activity and proceeds by sequential induction of antioxidant and proapoptotic targets. However, none of the thus far renowned p53 targets have proved able to abolish on their own the intracellular reactive oxygen species (ROS) accumulation caused by p53 deficiency, therefore pointing to the existence of other prominent and yet unknown p53 antioxidant targets. Here, we show that TP53INP1 represents such a target. Indeed, TP53INP1 transcript induction on oxidative stress is strictly dependent on p53. Mouse embryonic fibroblasts (MEF) and splenocytes derived from TP53INP1-deficient (inp1(-/-)) mice accumulate intracellular ROS, whereas overexpression of TP53INP1 in p53-deficient MEFs rescues ROS levels to those of p53-proficient cells, indicating that TP53INP1 antioxidant function is p53 independent. Furthermore, accumulation of ROS in inp1(-/-) cells on oxidant challenge is associated with decreased expression of p53 targets p21/Cdkn1a, Sesn2, TAp73, Puma, and Bax. Mutation of p53 Ser(58) (equivalent to human p53 Ser(46)) abrogates transcription of these genes, indicating that TP53INP1-mediated p53 Ser(58) phosphorylation is implicated in this process. In addition, TP53INP1 deficiency results in an antioxidant (N-acetylcysteine)-sensitive acceleration of cell proliferation. Finally, TP53INP1 deficiency increases oxidative stress-related lymphoma incidence and decreases survival of p53(+/-) mice. In conclusion, our data show that TP53INP1 is a major actor of p53-driven oxidative stress response that possesses both a p53-independent intracellular ROS regulatory function and a p53-dependent transcription regulatory function.

[1]  R. Weinberg,et al.  Growth-Inhibitory and Tumor- Suppressive Functions of p53 Depend on Its Repression of CD44 Expression , 2008, Cell.

[2]  Ladan Fazli,et al.  Tumor protein 53-induced nuclear protein 1 expression is repressed by miR-155, and its restoration inhibits pancreatic tumor development , 2007, Proceedings of the National Academy of Sciences.

[3]  Bernard Malissen,et al.  Colitis and Colitis-Associated Cancer Are Exacerbated in Mice Deficient for Tumor Protein 53-Induced Nuclear Protein 1 , 2007, Molecular and Cellular Biology.

[4]  A. Mercier,et al.  Early specific free radical-related cytotoxicity of gas phase cigarette smoke and its paradoxical temporary inhibition by tar: An electron paramagnetic resonance study with the spin trap DEPMPO. , 2006, Chemico-biological interactions.

[5]  G. Bossi,et al.  Ser58 of mouse p53 is the homologue of human Ser46 and is phosphorylated by HIPK2 in apoptosis , 2006, Cell Death and Differentiation.

[6]  Yoshio Miki,et al.  Protein Kinase C δ Regulates Ser46 Phosphorylation of p53 Tumor Suppressor in the Apoptotic Response to DNA Damage* , 2006, Journal of Biological Chemistry.

[7]  R. Tomasini,et al.  TP53INP1 is a novel p73 target gene that induces cell cycle arrest and cell death by modulating p73 transcriptional activity , 2005, Oncogene.

[8]  P. Chumakov,et al.  The antioxidant function of the p53 tumor suppressor , 2005, Nature Medicine.

[9]  W. Deppert,et al.  Transcription-independent pro-apoptotic functions of p53. , 2005, Current opinion in cell biology.

[10]  M. Oren,et al.  Novel link between E2F and p53: proapoptotic cofactors of p53 are transcriptionally upregulated by E2F , 2005, Cell Death and Differentiation.

[11]  Jian Yu,et al.  PUMA overexpression induces reactive oxygen species generation and proteasome-mediated stathmin degradation in colorectal cancer cells. , 2005, Cancer research.

[12]  M. Murphy,et al.  p53 Moves to Mitochondria: A Turn on the Path to Apoptosis , 2004, Cell cycle.

[13]  G. Blandino,et al.  HIPK2 neutralizes MDM2 inhibition rescuing p53 transcriptional activity and apoptotic function , 2004, Oncogene.

[14]  B. Halliwell,et al.  Measuring reactive species and oxidative damage in vivo and in cell culture: how should you do it and what do the results mean? , 2004, British journal of pharmacology.

[15]  E. Koonin,et al.  Regeneration of Peroxiredoxins by p53-Regulated Sestrins, Homologs of Bacterial AhpD , 2004, Science.

[16]  Sam W. Lee,et al.  Influence of Induced Reactive Oxygen Species in p53-Mediated Cell Fate Decisions , 2003, Molecular and Cellular Biology.

[17]  Daniel Isnardon,et al.  TP53INP1s and Homeodomain-interacting Protein Kinase-2 (HIPK2) Are Partners in Regulating p53 Activity* , 2003, Journal of Biological Chemistry.

[18]  R. Higashikubo,et al.  Redox regulation of the G1 to S phase transition in the mouse embryo fibroblast cell cycle. , 2003, Cancer research.

[19]  R. Tomasini,et al.  Molecular and Functional Characterization of the Stress-induced Protein (SIP) Gene and Its Two Transcripts Generated by Alternative Splicing , 2001, The Journal of Biological Chemistry.

[20]  Y Taya,et al.  p53DINP1, a p53-inducible gene, regulates p53-dependent apoptosis. , 2001, Molecular cell.

[21]  S. Granjeaud,et al.  Differential gene expression in CD3e- and RAG1-deficient thymuses: definition of a set of genes potentially involved in thymocyte maturation , 1999, Immunogenetics.

[22]  S. Pietri,et al.  5-(Diethoxyphosphoryl)-5-methyl-1-pyrroline N-oxide: a new efficient phosphorylated nitrone for the in vitro and in vivo spin trapping of oxygen-centered radicals. , 1995, Journal of medicinal chemistry.

[23]  R. Weinberg,et al.  Tumor spectrum analysis in p53-mutant mice , 1994, Current Biology.

[24]  L. Donehower,et al.  In vitro growth characteristics of embryo fibroblasts isolated from p53-deficient mice. , 1993, Oncogene.

[25]  R. Mason,et al.  When are metal ion-dependent hydroxyl and alkoxyl radical adducts of 5,5-dimethyl-1-pyrroline N-oxide artifacts? , 1992, Archives of biochemistry and biophysics.