The notch regulator MAML1 interacts with p53 and functions as a coactivator. J Biol Chem 2007 Apr 20;282(16):11969-81
Date
02/24/2007Pubmed ID
17317671DOI
10.1074/jbc.M608974200Scopus ID
2-s2.0-34249740225 (requires institutional sign-in at Scopus site) 65 CitationsAbstract
Members of the evolutionarily conserved Mastermind (MAM) protein family, including the three related mammalian Mastermind-like (MAML) proteins MAML1-3, function as crucial coactivators of Notch-mediated transcriptional activation. Given the recent evidence of cross-talk between the p53 and Notch signal transduction pathways, we have investigated whether MAML1 may also be a transcriptional coactivator of p53. Indeed, we show here that MAML1 is able to interact with p53. We show that MAML1-p53 interaction involves the N-terminal region of MAML1 and the DNA-binding domain of p53, and we use a chromatin immunoprecipitation assay to show that MAML1 is part of the activator complex that binds to native p53-response elements within the promoter of the p53 target genes. Overexpression of wild-type MAML1 as well as a mutant, defective in Notch signaling, enhanced the p53-dependent gene induction in mammalian cells, whereas MAML1 knockdown reduced the p53-dependent gene expression. MAML1 increases the half-life of p53 protein and enhances its phosphorylation/acetylation upon DNA damage of cells. Finally, RNA interference-mediated knockdown of the single Caenorhabditis elegans MAML homolog, Lag-3, led to substantial abrogation of p53-mediated germ-cell apoptotic response to DNA damage and markedly reduced the expression of Ced-13 and Egl-1, downstream pro-apoptotic targets of the C. elegans p53 homolog Cep-1. Thus, we present evidence for a novel coactivator function of MAML1 for p53, independent of its function as a coactivator of Notch signaling pathway.
Author List
Zhao Y, Katzman RB, Delmolino LM, Bhat I, Zhang Y, Gurumurthy CB, Germaniuk-Kurowska A, Reddi HV, Solomon A, Zeng MS, Kung A, Ma H, Gao Q, Dimri G, Stanculescu A, Miele L, Wu L, Griffin JD, Wazer DE, Band H, Band VMESH terms used to index this publication - Major topics in bold
AnimalsApoptosis
Caenorhabditis elegans
Caenorhabditis elegans Proteins
Cell Line, Tumor
DNA Damage
DNA-Binding Proteins
Humans
Nuclear Proteins
Phosphorylation
Receptors, Notch
Repressor Proteins
Signal Transduction
Trans-Activators
Transcription Factors
Transcriptional Activation
Tumor Suppressor Protein p53