Quantitative analysis of residual folding and DNA binding in mutant p53 core domain: definition of mutant states for rescue in cancer therapy

Abstract The TP53 tumor suppressor gene encodes a DNA-binding transcription factor that regulates multiple cellular processes including cell growth and cell death. The ability of p53 to bind to DNA and activate transcription is tightly regulated by post-translational modifications and is dependent on a reducing cellular environment. Some p53 transcriptional target genes are involved in regulation of the cellular redox homeostasis, e.g. TIGAR and GLS2. A large fraction of human tumors carry TP53 mutations, most commonly missense mutations that lead to single amino acid substitutions in the core domain. Mutant p53 proteins can acquire so called gain-of-function activities and influence the cellular redox balance in various ways, for instance by binding of the Nrf2 transcription factor, a major regulator of cellular redox state. The DNA-binding core domain of p53 has 10 cysteine residues, three of which participate in holding a zinc atom that is critical for p53 structure and function. Several novel compounds that refold and reactivate missense mutant p53 bind to specific p53 cysteine residues. These compounds can also react with other thiols and target components of the cellular redox system, such as glutathione. Dual targeting of mutant p53 and redox homeostasis may allow more efficient treatment of cancer.

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APR-246 reactivates mutant p53 by targeting cysteines 124 and 277

10.1101/214049 ◽

2017 ◽

Cited By ~ 1

Author(s):

Qiang Zhang ◽

Vladimir J.N. Bykov ◽

Klas G. Wiman ◽

Joanna Zawacka-Pankau

Keyword(s):

Tumor Suppressor ◽

Dna Binding ◽

Rational Design ◽

Protein Unfolding ◽

Suppressor Gene ◽

Functional Restoration ◽

Mutant P53 ◽

Missense Mutations ◽

Core Domain ◽

Promising Strategy

AbstractThe TP53 tumor suppressor gene is frequently inactivated in human tumors by missense mutations in the DNA binding domain. TP53 mutations lead to protein unfolding, decreased thermostability and loss of DNA binding and transcription factor function. Pharmacological targeting of mutant p53 to restore its tumor suppressor function is a promising strategy for cancer therapy. The mutant p53 reactivating compound APR-246 (PRIMA-1Met) has been successfully tested in a phase I/IIa clinical trial. APR-246 is converted to the reactive electrophile methylene quinuclidinone (MQ), which binds covalently to p53 core domain. We identified cysteine 277 as a prime binding target for MQ in p53. Cys277 is also essential for MQ-mediated thermostabilization of wild-type, R175H and R273H mutant p53, while both Cys124 and Cys277 are required for APR-246-mediated functional restoration of R175H mutant p53 in living tumor cells. These findings may open opportunities for rational design of novel mutant p53-targeting compounds.

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Faculty Opinions recommendation of Targeting mutant p53 for efficient cancer therapy.

Faculty Opinions – Post-Publication Peer Review of the Biomedical Literature ◽

10.3410/f.732305141.793542982 ◽

2018 ◽

Author(s):

Thomas Kodadek

Keyword(s):

Cancer Therapy ◽

Mutant P53

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Rely on Each Other: DNA Binding Cooperativity Shapes p53 Functions in Tumor Suppression and Cancer Therapy

Cancers ◽

10.3390/cancers13102422 ◽

2021 ◽

Vol 13 (10) ◽

pp. 2422

Author(s):

Oleg Timofeev ◽

Thorsten Stiewe

Keyword(s):

Cancer Therapy ◽

Dna Binding ◽

Cell Fate ◽

Tumor Suppression ◽

Quaternary Structure ◽

Three Dimensional ◽

Structural Basis ◽

Sequence Specificity ◽

Cell Fate Decisions ◽

Cancer Mutations

p53 is a tumor suppressor that is mutated in half of all cancers. The high clinical relevance has made p53 a model transcription factor for delineating general mechanisms of transcriptional regulation. p53 forms tetramers that bind DNA in a highly cooperative manner. The DNA binding cooperativity of p53 has been studied by structural and molecular biologists as well as clinical oncologists. These experiments have revealed the structural basis for cooperative DNA binding and its impact on sequence specificity and target gene spectrum. Cooperativity was found to be critical for the control of p53-mediated cell fate decisions and tumor suppression. Importantly, an estimated number of 34,000 cancer patients per year world-wide have mutations of the amino acids mediating cooperativity, and knock-in mouse models have confirmed such mutations to be tumorigenic. While p53 cancer mutations are classically subdivided into “contact” and “structural” mutations, “cooperativity” mutations form a mechanistically distinct third class that affect the quaternary structure but leave DNA contacting residues and the three-dimensional folding of the DNA-binding domain intact. In this review we discuss the concept of DNA binding cooperativity and highlight the unique nature of cooperativity mutations and their clinical implications for cancer therapy.

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Characterization of Spent Ni-MH Batteries

Materials Science Forum ◽

10.4028/www.scientific.net/msf.730-732.569 ◽

2012 ◽

Vol 730-732 ◽

pp. 569-574

Author(s):

Marta Cabral ◽

Fernanda Margarido ◽

Carlos A. Nogueira

Keyword(s):

Quantitative Analysis ◽

Electrode Materials ◽

Phase Identification ◽

Recycling Process ◽

X Ray ◽

Leaching Experiments ◽

Plastic Components ◽

Definition Of ◽

Physical And Chemical

Spent Ni-MH batteries are not considered too dangerous for the environment, but they have a considerable economical value due to the chemical composition of electrodes which are highly concentrated in metals. The present work aimed at the physical and chemical characterisation of spent cylindrical and thin prismatic Ni-MH batteries, contributing for a better definition of the recycling process of these spent products. The electrode materials correspond to more than 50% of the batteries weight and contain essentially nickel and rare earths (RE), and other secondary elements (Co, Mn, Al). The remaining components are the steel parts from the external case and supporting grids (near 30%) containing Fe and Ni, and the plastic components (<10%). Elemental quantitative analysis showed that the electrodes are highly concentrated in metals. Phase identification by X-ray powder diffraction combined with chemical analysis and leaching experiments allowed advancing the electrode materials composition. The cathode is essentially constituted by 6% metallic Ni, 66% Ni(OH)2, 4.3% Co(OH)2 and the anode consists mainly in 62% RENi5 and 17% of substitutes and/or additives such as Co, Mn and Al.

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Generalized Wavelet Fisher’s Information of1/fαSignals

Advances in Mathematical Physics ◽

10.1155/2015/210592 ◽

2015 ◽

Vol 2015 ◽

pp. 1-9 ◽

Cited By ~ 1

Author(s):

Julio Ramírez-Pacheco ◽

Homero Toral-Cruz ◽

Luis Rizo-Domínguez ◽

Joaquin Cortez-Gonzalez

Keyword(s):

Fisher Information ◽

Gaussian Noise ◽

Structural Breaks ◽

Wavelet Domain ◽

Fractional Gaussian Noise ◽

Domain Definition ◽

Potential Applications ◽

Definition Of ◽

The Time Domain ◽

Fisher's Information

This paper defines the generalized wavelet Fisher information of parameterq. This information measure is obtained by generalizing the time-domain definition of Fisher’s information of Furuichi to the wavelet domain and allows to quantify smoothness and correlation, among other signals characteristics. Closed-form expressions of generalized wavelet Fisher information for1/fαsignals are determined and a detailed discussion of their properties, characteristics and their relationship with waveletq-Fisher information are given. Information planes of1/fsignals Fisher information are obtained and, based on these, potential applications are highlighted. Finally, generalized wavelet Fisher information is applied to the problem of detecting and locating weak structural breaks in stationary1/fsignals, particularly for fractional Gaussian noise series. It is shown that by using a joint Fisher/F-Statistic procedure, significant improvements in time and accuracy are achieved in comparison with the sole application of theF-statistic.

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Quantitative analysis of the mechanism of DNA binding by Bacillus DnaA protein

Biochimie ◽

10.1016/j.biochi.2012.08.019 ◽

2012 ◽

Vol 94 (12) ◽

pp. 2764-2775 ◽

Cited By ~ 4

Author(s):

Shawna M. Rotoli ◽

Esther Biswas-Fiss ◽

Subhasis B. Biswas

Keyword(s):

Quantitative Analysis ◽

Dna Binding ◽

Dnaa Protein

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Mutant p53 in cancer therapy—the barrier or the path

Journal of Molecular Cell Biology ◽

10.1093/jmcb/mjy072 ◽

2018 ◽

Vol 11 (4) ◽

pp. 293-305 ◽

Cited By ~ 43

Author(s):

Xiang Zhou ◽

Qian Hao ◽

Hua Lu

Keyword(s):

Cancer Therapy ◽

Mutant P53

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Mutant p53 Sequestration of the MDM2 Acidic Domain Inhibits E3 Ligase Activity

Molecular and Cellular Biology ◽

10.1128/mcb.00375-18 ◽

2018 ◽

Vol 39 (4) ◽

Cited By ~ 3

Author(s):

Leixiang Yang ◽

Tanjing Song ◽

Qian Cheng ◽

Lihong Chen ◽

Jiandong Chen

Keyword(s):

Tumor Cells ◽

Recent Work ◽

Intramolecular Interaction ◽

E3 Ligase ◽

Mutant P53 ◽

Wild Type ◽

Gain Of Function ◽

Core Domain ◽

Acidic Domain ◽

Wild Type P53

ABSTRACT Missense p53 mutants often accumulate in tumors and drive progression through gain of function. MDM2 efficiently degrades wild-type p53 but fails to degrade mutant p53 in tumor cells. Previous studies revealed that mutant p53 inhibits MDM2 autoubiquitination, suggesting that the interaction inhibits MDM2 E3 activity. Recent work showed that MDM2 E3 activity is stimulated by intramolecular interaction between the RING and acidic domains. Here, we show that in the mutant p53-MDM2 complex, the mutant p53 core domain binds to the MDM2 acidic domain with significantly higher avidity than wild-type p53. The mutant p53-MDM2 complex is deficient in catalyzing ubiquitin release from the activated E2 conjugating enzyme. An MDM2 construct with extra copies of the acidic domain is resistant to inhibition by mutant p53 and efficiently promotes mutant p53 ubiquitination and degradation. The results suggest that mutant p53 interferes with the intramolecular autoactivation mechanism of MDM2, contributing to reduced ubiquitination and increased accumulation in tumor cells.

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Human GATA-3 trans-activation, DNA-binding, and nuclear localization activities are organized into distinct structural domains.

Molecular and Cellular Biology ◽

10.1128/mcb.14.3.2201 ◽

1994 ◽

Vol 14 (3) ◽

pp. 2201-2212 ◽

Cited By ~ 78

Author(s):

Z Yang ◽

L Gu ◽

P H Romeo ◽

D Bories ◽

H Motohashi ◽

...

Keyword(s):

Amino Acids ◽

Dna Binding ◽

Zinc Finger ◽

Nuclear Localization ◽

Structural Domains ◽

Cellular Genes ◽

Dna Binding Site ◽

Discrete Domains ◽

Definition Of ◽

Site Recognition

GATA-3 is a zinc finger transcription factor which is expressed in a highly restricted and strongly conserved tissue distribution pattern in vertebrate organisms, specifically, in a subset of hematopoietic cells, in cells within the central and peripheral nervous systems, in the kidney, and in placental trophoblasts. Tissue-specific cellular genes regulated by GATA-3 have been identified in T lymphocytes and the placenta, while GATA-3-regulated genes in the nervous system and kidney have not yet been defined. We prepared monoclonal antibodies with which we could dissect the biochemical and functional properties of human GATA-3. The results of these experiments show some anticipated phenotypes, for example, the definition of discrete domains required for specific DNA-binding site recognition (amino acids 303 to 348) and trans activation (amino acids 30 to 74). The signaling sequence for nuclear localization of human GATA-3 is a property conferred by sequences within and surrounding the amino finger (amino acids 249 to 311) of the protein, thereby assigning a function to this domain and thus explaining the curious observation that this zinc finger is dispensable for DNA binding by the GATA family of transcription factors.

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