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Huang Y, Li W, Foo T, Ji JH, Wu B, Tomimatsu N, Fang Q, Gao B, Long M, Xu J, Maqbool R, Mukherjee B, Ni T, Alejo S, He Y, Burma S, Lan L, Xia B, Zhao W. DSS1 restrains BRCA2's engagement with dsDNA for homologous recombination, replication fork protection, and R-loop homeostasis. Nat Commun 2024; 15:7081. [PMID: 39152168 PMCID: PMC11329725 DOI: 10.1038/s41467-024-51557-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/03/2024] [Accepted: 08/09/2024] [Indexed: 08/19/2024] Open
Abstract
DSS1, essential for BRCA2-RAD51 dependent homologous recombination (HR), associates with the helical domain (HD) and OB fold 1 (OB1) of the BRCA2 DSS1/DNA-binding domain (DBD) which is frequently targeted by cancer-associated pathogenic variants. Herein, we reveal robust ss/dsDNA binding abilities in HD-OB1 subdomains and find that DSS1 shuts down HD-OB1's DNA binding to enable ssDNA targeting of the BRCA2-RAD51 complex. We show that C-terminal helix mutations of DSS1, including the cancer-associated R57Q mutation, disrupt this DSS1 regulation and permit dsDNA binding of HD-OB1/BRCA2-DBD. Importantly, these DSS1 mutations impair BRCA2/RAD51 ssDNA loading and focus formation and cause decreased HR efficiency, destabilization of stalled forks and R-loop accumulation, and hypersensitize cells to DNA-damaging agents. We propose that DSS1 restrains the intrinsic dsDNA binding of BRCA2-DBD to ensure BRCA2/RAD51 targeting to ssDNA, thereby promoting optimal execution of HR, and potentially replication fork protection and R-loop suppression.
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Affiliation(s)
- Yuxin Huang
- Department of Biochemistry and Structural Biology, University of Texas Health and Science Center, San Antonio, TX, 78229, USA
| | - Wenjing Li
- Department of Biochemistry and Structural Biology, University of Texas Health and Science Center, San Antonio, TX, 78229, USA
| | - Tzeh Foo
- Department of Radiation Oncology, Rutgers Cancer Institute of New Jersey and Robert Wood Johnson Medical School, New Brunswick, NJ, 08903, USA
| | - Jae-Hoon Ji
- Department of Biochemistry and Structural Biology, University of Texas Health and Science Center, San Antonio, TX, 78229, USA
- Greehey Children's Cancer Research Institute, University of Texas Health Science Center at San Antonio, San Antonio, TX, 78229, USA
| | - Bo Wu
- Department of Biochemistry and Structural Biology, University of Texas Health and Science Center, San Antonio, TX, 78229, USA
| | - Nozomi Tomimatsu
- Department of Neurosurgery, University of Texas Health Science Center at San Antonio, San Antonio, TX, 78229, USA
| | - Qingming Fang
- Department of Biochemistry and Structural Biology, University of Texas Health and Science Center, San Antonio, TX, 78229, USA
- Greehey Children's Cancer Research Institute, University of Texas Health Science Center at San Antonio, San Antonio, TX, 78229, USA
| | - Boya Gao
- Department of Radiation Oncology, Massachusetts General Hospital, Harvard Medical School, Boston, MA, 02129, USA
| | - Melissa Long
- Department of Radiation Oncology, Massachusetts General Hospital, Harvard Medical School, Boston, MA, 02129, USA
| | - Jingfei Xu
- Department of Molecular Biosciences, Northwestern University, Evanston, IL, USA
| | - Rouf Maqbool
- Department of Biochemistry and Structural Biology, University of Texas Health and Science Center, San Antonio, TX, 78229, USA
| | - Bipasha Mukherjee
- Department of Radiation Oncology, Rutgers Cancer Institute of New Jersey and Robert Wood Johnson Medical School, New Brunswick, NJ, 08903, USA
| | - Tengyang Ni
- Department of Biochemistry and Structural Biology, University of Texas Health and Science Center, San Antonio, TX, 78229, USA
| | - Salvador Alejo
- Department of Obstetrics & Gynecology, University of Texas Health Science Center, San Antonio, TX, 78229, USA
| | - Yuan He
- Department of Molecular Biosciences, Northwestern University, Evanston, IL, USA
| | - Sandeep Burma
- Department of Biochemistry and Structural Biology, University of Texas Health and Science Center, San Antonio, TX, 78229, USA
- Department of Neurosurgery, University of Texas Health Science Center at San Antonio, San Antonio, TX, 78229, USA
| | - Li Lan
- Department of Radiation Oncology, Massachusetts General Hospital, Harvard Medical School, Boston, MA, 02129, USA
- Department of Molecular Genetics and Microbiology, School of Medicine, Duke University, Durham, NC, 27710, USA
| | - Bing Xia
- Department of Radiation Oncology, Rutgers Cancer Institute of New Jersey and Robert Wood Johnson Medical School, New Brunswick, NJ, 08903, USA
| | - Weixing Zhao
- Department of Biochemistry and Structural Biology, University of Texas Health and Science Center, San Antonio, TX, 78229, USA.
- Greehey Children's Cancer Research Institute, University of Texas Health Science Center at San Antonio, San Antonio, TX, 78229, USA.
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2
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Yuan L, Liu G, Zhao D, Zhu H, Qi J, Lu K. Interaction of p53 with BRC analogs: A comparative design assisted by ZDOCK and CABS-Dock simulation. J Mol Struct 2023. [DOI: 10.1016/j.molstruc.2022.134109] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/14/2022]
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3
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Chatterjee C, Singh SK. Peptide and protein chemistry approaches to study the tumor suppressor protein p53. Org Biomol Chem 2022; 20:5500-5509. [PMID: 35786742 PMCID: PMC10112546 DOI: 10.1039/d2ob00902a] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
The tumor suppressor and master gene regulator protein p53 has been the subject of intense investigation for several decades due to its mutation in about half of all human cancers. However, mechanistic studies of p53 in cells are complicated by its many dynamic binding partners and heterogeneous post-translational modifications. The design of therapeutics that rescue p53 functions in cells requires a mechanistic understanding of its protein-protein interactions in specific protein complexes and identifying changes in p53 activity by diverse post-translational modifications. This review highlights the important roles that peptide and protein chemistry have played in biophysical and biochemical studies aimed at elucidating p53 regulation by several key binding partners. The design of various peptide inhibitors that rescue p53 function in cells and new opportunities in targeting p53-protein interactions are discussed. In addition, the review highlights the importance of a protein semisynthesis approach to comprehend the role of site-specific PTMs in p53 regulation.
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Affiliation(s)
- Champak Chatterjee
- Department of Chemistry, University of Washington, Seattle, WA 98195, USA.
| | - Sumeet K Singh
- Department of Chemistry, University of Washington, Seattle, WA 98195, USA.
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4
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Whole-exome sequencing in eccrine porocarcinoma indicates promising therapeutic strategies. Cancer Gene Ther 2022; 29:697-708. [PMID: 34045664 PMCID: PMC9209330 DOI: 10.1038/s41417-021-00347-z] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2020] [Revised: 04/23/2021] [Accepted: 05/10/2021] [Indexed: 02/06/2023]
Abstract
Malignant sweat gland tumours are rare, with the most common form being Eccrine porocarcinoma (EP). To investigate the mutational landscape of EP, we performed whole-exome sequencing (WES) on 14 formalin-fixed paraffin-embedded samples of matched primary EP and healthy surrounding tissue. Mutational profiling revealed a high overall median mutation rate. This was attributed to signatures of mutational processes related to ultraviolet (UV) exposure, APOBEC enzyme dysregulation, and defective homologous double-strand break repair. All of these processes cause genomic instability and are implicated in carcinogenesis. Recurrent driving somatic alterations were detected in the EP candidate drivers TP53, FAT2, CACNA1S, and KMT2D. The analyses also identified copy number alterations and recurrent gains and losses in several chromosomal regions including that containing BRCA2, as well as deleterious alterations in multiple HRR components. In accordance with this reduced or even a complete loss of BRCA2 protein expression was detected in 50% of the investigated EP tumours. Our results implicate crucial oncogenic driver pathways and suggest that defective homologous double-strand break repair and the p53 pathway are involved in EP aetiology. Targeting of the p53 axis and PARP inhibition, and/or immunotherapy may represent promising treatment strategies.
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5
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Hernández-Suárez B, Gillespie DA, Pawlak A. DNA Damage Response (DDR) proteins in canine cancer as potential research targets in comparative oncology. Vet Comp Oncol 2021; 20:347-361. [PMID: 34923737 PMCID: PMC9304296 DOI: 10.1111/vco.12795] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2021] [Revised: 12/15/2021] [Accepted: 12/16/2021] [Indexed: 11/22/2022]
Abstract
The DNA damage response (DDR) is a complex signal transduction network that is activated when endogenous or exogenous genotoxins damage or interfere with the replication of genomic DNA. Under such conditions, the DDR promotes DNA repair and ensures accurate replication and division of the genome. High levels of genomic instability are frequently observed in cancers and can stem from germline loss‐of‐function mutations in certain DDR genes, such as BRCA1, BRCA2, and p53, that form the basis of human cancer predisposition syndromes. In addition, mutation and/or aberrant expression of multiple DDR genes are frequently observed in sporadic human cancers. As a result, the DDR is considered to represent a viable target for cancer therapy in humans and a variety of strategies are under investigation. Cancer is also a significant cause of mortality in dogs, a species that offers certain advantages for experimental oncology. Domestic dogs present numerous inbred lines, many of which display predisposition to specific forms of cancer and the study of which may provide insight into the biological basis of this susceptibility. In addition, clinical trials are possible in dogs and may lead to therapeutic insights that could ultimately be extended to humans. Here we review what is known specifically about the DDR in dogs and discuss how this knowledge could be extended and exploited to advance experimental oncology in this species.
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Affiliation(s)
- Beatriz Hernández-Suárez
- Department of Pharmacology and Toxicology, Faculty of Veterinary Medicine, Wroclaw University of Environmental and Life Sciences, Poland
| | - David A Gillespie
- Instituto de Tecnologías Biomédicas, Facultad de Medicina, Campus Ciencias de la Salud, Universidad de La Laguna, La Laguna 38071, Tenerife, Spain
| | - Aleksandra Pawlak
- Department of Pharmacology and Toxicology, Faculty of Veterinary Medicine, Wroclaw University of Environmental and Life Sciences, Poland
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6
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Le HP, Heyer WD, Liu J. Guardians of the Genome: BRCA2 and Its Partners. Genes (Basel) 2021; 12:genes12081229. [PMID: 34440403 PMCID: PMC8394001 DOI: 10.3390/genes12081229] [Citation(s) in RCA: 19] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2021] [Revised: 08/04/2021] [Accepted: 08/06/2021] [Indexed: 12/28/2022] Open
Abstract
The tumor suppressor BRCA2 functions as a central caretaker of genome stability, and individuals who carry BRCA2 mutations are predisposed to breast, ovarian, and other cancers. Recent research advanced our mechanistic understanding of BRCA2 and its various interaction partners in DNA repair, DNA replication support, and DNA double-strand break repair pathway choice. In this review, we discuss the biochemical and structural properties of BRCA2 and examine how these fundamental properties contribute to DNA repair and replication fork stabilization in living cells. We highlight selected BRCA2 binding partners and discuss their role in BRCA2-mediated homologous recombination and fork protection. Improved mechanistic understanding of how BRCA2 functions in genome stability maintenance can enable experimental evidence-based evaluation of pathogenic BRCA2 mutations and BRCA2 pseudo-revertants to support targeted therapy.
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Affiliation(s)
- Hang Phuong Le
- Department of Microbiology and Molecular Genetics, University of California, Davis, CA 95616, USA; (H.P.L.); (W.-D.H.)
| | - Wolf-Dietrich Heyer
- Department of Microbiology and Molecular Genetics, University of California, Davis, CA 95616, USA; (H.P.L.); (W.-D.H.)
- Department of Molecular and Cellular Biology, University of California, Davis, CA 95616, USA
| | - Jie Liu
- Department of Microbiology and Molecular Genetics, University of California, Davis, CA 95616, USA; (H.P.L.); (W.-D.H.)
- Correspondence: ; Tel.: +1-530-752-3016
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7
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Ha MJ, Stingo FC, Baladandayuthapani V. Bayesian Structure Learning in Multi-layered Genomic Networks. J Am Stat Assoc 2021; 116:605-618. [PMID: 34239216 DOI: 10.1080/01621459.2020.1775611] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Integrative network modeling of data arising from multiple genomic platforms provides insight into the holistic picture of the interactive system, as well as the flow of information across many disease domains including cancer. The basic data structure consists of a sequence of hierarchically ordered datasets for each individual subject, which facilitates integration of diverse inputs, such as genomic, transcriptomic, and proteomic data. A primary analytical task in such contexts is to model the layered architecture of networks where the vertices can be naturally partitioned into ordered layers, dictated by multiple platforms, and exhibit both undirected and directed relationships. We propose a multi-layered Gaussian graphical model (mlGGM) to investigate conditional independence structures in such multi-level genomic networks in human cancers. We implement a Bayesian node-wise selection (BANS) approach based on variable selection techniques that coherently accounts for the multiple types of dependencies in mlGGM; this flexible strategy exploits edge-specific prior knowledge and selects sparse and interpretable models. Through simulated data generated under various scenarios, we demonstrate that BANS outperforms other existing multivariate regression-based methodologies. Our integrative genomic network analysis for key signaling pathways across multiple cancer types highlights commonalities and differences of p53 integrative networks and epigenetic effects of BRCA2 on p53 and its interaction with T68 phosphorylated CHK2, that may have translational utilities of finding biomarkers and therapeutic targets.
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Affiliation(s)
- Min Jin Ha
- Department of Biostatistics, The University of Texas MD Anderson Cancer Center
| | - Francesco Claudio Stingo
- Department of Statistics, Computer Science, Applications "G. Parenti", The University of Florence
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8
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Sibuh BZ, Khanna S, Taneja P, Sarkar P, Taneja NK. Molecular docking, synthesis and anticancer activity of thiosemicarbazone derivatives against MCF-7 human breast cancer cell line. Life Sci 2021; 273:119305. [PMID: 33675898 DOI: 10.1016/j.lfs.2021.119305] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2020] [Revised: 02/24/2021] [Accepted: 02/25/2021] [Indexed: 02/08/2023]
Abstract
BACKGROUND The aim of this study was to synthesize and evaluate anticancer activity of 2-hydroxy benzaldehyde and 4-hydroxy benzaldehyde thiosemicarbazone (2-HBTSc and 4-HBTSc) against MCF-7 breast cancer cell line. MATERIALS AND METHODS The ligands were prepared and characterized by UV vis, IR and NMR. MTT assay was used to assess viability of cells. RNA isolation, extraction and cDNA synthesis were done. Then all groups were subjected to RT-qPCR using Gene expression specific primers. Also, western blot protein expression and molecular docking were done. Two-way ANOVA with Tukey post-hoc test was employed to test the significance using GraphPad Prism. RESULTS The IC50 values were 3.36μg/ml and 3.60μg/ml for 2-HBTSc and 4-HBTSc treated MCF-7 tumor cells respectively. Tumor cell growth inhibition ranged from 38 to 49.27% in 4-HBTSc treated cells, and 19 to 25% in 2-HBTSc treated cells with increase in doses 5 μg/ml to 20 μg/ml. The protein and gene expression result showed a significant upregulation in tumor suppressor and apoptosis inducing genes while, oncogene activity was significantly downregulated. Specifically, BRCA2 and pRB gene showed the highest expression in 4-HBTSc and 2-HBTSc treated cells respectively. Conversely, RAS oncogene was downregulated significantly. Docking result showed that both 2-HBTSc and 4-HBTSc have the potential to inhibit Estrogen Receptor Alpha Ligand Binding Domain, Human 17-Beta-hydroxysteroid dehydrogenase type 1 mutant protein and Human Topoisomerase II alpha that are expressed more during Breast Cancer. CONCLUSION The findings of this study imply that the test compound has potential for further study.
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Affiliation(s)
- Belay Zeleke Sibuh
- Department of Biotechnology, School of Engineering and Technology, Sharda University, Greater Noida, U. P., India
| | - Sonia Khanna
- Department of Chemistry and Biochemistry, School of Basic Sciences and Research, Sharda University, Greater Noida, U. P., India
| | - Pankaj Taneja
- Department of Biotechnology, School of Engineering and Technology, Sharda University, Greater Noida, U. P., India.
| | - Paratpar Sarkar
- Department of Chemistry and Biochemistry, School of Basic Sciences and Research, Sharda University, Greater Noida, U. P., India
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9
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Baughan S, Tainsky MA. K3326X and Other C-Terminal BRCA2 Variants Implicated in Hereditary Cancer Syndromes: A Review. Cancers (Basel) 2021; 13:447. [PMID: 33503928 PMCID: PMC7865497 DOI: 10.3390/cancers13030447] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2020] [Revised: 01/11/2021] [Accepted: 01/21/2021] [Indexed: 02/06/2023] Open
Abstract
Whole genome analysis and the search for mutations in germline and tumor DNAs is becoming a major tool in the evaluation of risk as well as the management of hereditary cancer syndromes. Because of the identification of cancer predisposition gene panels, thousands of such variants have been catalogued yet many remain unclassified, presenting a clinical challenge for the management of hereditary cancer syndromes. Although algorithms exist to estimate the likelihood of a variant being deleterious, these tools are rarely used for clinical decision-making. Here, we review the progress in classifying K3326X, a rare truncating variant on the C-terminus of BRCA2 and review recent literature on other novel single nucleotide polymorphisms, SNPs, on the C-terminus of the protein, defined in this review as the portion after the final BRC repeat (amino acids 2058-3418).
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Affiliation(s)
- Scott Baughan
- Department of Oncology, Wayne State University School of Medicine, Detroit, MI 48201, USA;
- Center for Molecular Medicine and Genetics, Wayne State University School of Medicine, Detroit, MI 48201, USA
| | - Michael A. Tainsky
- Department of Oncology, Wayne State University School of Medicine, Detroit, MI 48201, USA;
- Center for Molecular Medicine and Genetics, Wayne State University School of Medicine, Detroit, MI 48201, USA
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10
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Gordon CK, Luu R, Lynn D. Capturing nested information from disordered peptide phases. Pept Sci (Hoboken) 2020. [DOI: 10.1002/pep2.24215] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Affiliation(s)
| | - Regina Luu
- Departments of Chemistry and Biology Emory University Atlanta Georgia USA
| | - David Lynn
- Departments of Chemistry and Biology Emory University Atlanta Georgia USA
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11
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Muyskens JB, Winbush A, Foote DM, Turnbull DW, Dreyer HC. Essential amino acid supplementation alters the p53 transcriptional response and cytokine gene expression following total knee arthroplasty. J Appl Physiol (1985) 2020; 129:980-991. [PMID: 32881622 DOI: 10.1152/japplphysiol.00022.2020] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Reducing muscle atrophy following orthopedic surgery is critical during the postoperative period. Our previous work in patients who underwent total knee arthroplasty (TKA) showed that the vast majority of atrophy occurs within 2 wk following surgery and that essential amino acid (EAA) supplementation attenuates this atrophy. We used RNA-sequencing (RNA-seq) to identify genes associated with atrophy after TKA with and without EAAs. Analysis of overrepresented gene-ontology terms revealed that p53 signaling and the cytokine-cytokine receptor pathways were highly upregulated after TKA. Relative to the placebo group, the EAA group had altered expression of p53 regulators such as MDM2. This altered expression may account for differences between groups in timing of upregulation of some p53 targets such as apoptosis genes, and may account for the reduction in muscle loss in the subjects receiving EAAs. Furthermore, we observed altered expression of a large number of cytokine-signaling genes including TNFRSF12A, which plays a critical role in muscle atrophy, myogenesis, fibrosis, and the noncanonical NF-κB pathway.NEW & NOTEWORTHY Total knee arthroplasty is the most frequently performed inpatient surgical procedure for those over 45 yr in the United States. Following surgery, patients lose a large amount of muscle, which impacts functional mobility. Previously, our laboratory found that supplementing patients' diets with essential amino acids (EAAs) reduces postsurgical muscle loss. Here, our goal was to characterize the transcriptional changes associated with surgery with and without EAA supplementation to uncover the underlying mechanisms by which EAAs attenuate this muscle loss.
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Affiliation(s)
| | - Ari Winbush
- Institute of Ecology and Evolution, University of Oregon, Eugene, Oregon
| | - Douglas M Foote
- Department of Human Physiology, University of Oregon, Eugene, Oregon
| | - Douglas W Turnbull
- Genomics and Cell Characterization Core Facility, University of Oregon, Eugene, Oregon
| | - Hans C Dreyer
- Department of Human Physiology, University of Oregon, Eugene, Oregon
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12
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Ecsédi P, Gógl G, Hóf H, Kiss B, Harmat V, Nyitray L. Structure Determination of the Transactivation Domain of p53 in Complex with S100A4 Using Annexin A2 as a Crystallization Chaperone. Structure 2020; 28:943-953.e4. [PMID: 32442400 DOI: 10.1016/j.str.2020.05.001] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/26/2019] [Revised: 04/05/2020] [Accepted: 05/01/2020] [Indexed: 11/29/2022]
Abstract
To fully understand the environmental factors that influence crystallization is an enormous task, therefore crystallographers are still forced to work "blindly" trying as many crystallizing conditions and mutations to improve crystal packing as possible. Numerous times these random attempts simply fail even when using state-of-the-art techniques. As an alternative, crystallization chaperones, having good crystal-forming properties, can be invoked. Today, the almost exclusively used such protein is the maltose-binding protein (MBP) and crystallographers need other widely applicable options. Here, we introduce annexin A2 (ANXA2), which has just as good, if not better, crystal-forming ability than the wild-type MBP. Using ANXA2 as heterologous fusion partner, we were able to solve the atomic resolution structure of a challenging crystallization target, the transactivation domain (TAD) of p53 in complex with the metastasis-associated protein S100A4. p53 TAD forms an asymmetric fuzzy complex with the symmetric S1004 and could interfere with its function.
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Affiliation(s)
- Péter Ecsédi
- Department of Biochemistry, ELTE Eötvös Loránd University, Budapest 1117, Hungary
| | - Gergő Gógl
- Department of Biochemistry, ELTE Eötvös Loránd University, Budapest 1117, Hungary; Institute of Genetics and of Molecular and Cellular Biology, IGBMC, Strasbourg 67400, France
| | - Henrietta Hóf
- Department of Biochemistry, ELTE Eötvös Loránd University, Budapest 1117, Hungary
| | - Bence Kiss
- Department of Biochemistry, ELTE Eötvös Loránd University, Budapest 1117, Hungary
| | - Veronika Harmat
- ELTE Eötvös Loránd University, Institute of Chemistry, MTA-ELTE Protein Modeling Research Group, Budapest 1117, Hungary
| | - László Nyitray
- Department of Biochemistry, ELTE Eötvös Loránd University, Budapest 1117, Hungary.
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13
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Ning S, Liu J, Liu N, Yan D. The accuracy of force fields on the simulation of intrinsically disordered proteins: A benchmark test on the human p53 tumor suppressor. JOURNAL OF THEORETICAL & COMPUTATIONAL CHEMISTRY 2020. [DOI: 10.1142/s021963362050011x] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
Intrinsically disordered proteins (IDPs) are a class of proteins without stable three-dimensional structures under physiological conditions. IDPs exhibit high dynamic nature and could be described by structural ensembles. As one of the most widely used tools, molecular dynamics (MD) simulation could provide the atomic descriptions of the structural ensemble of IDPs. However, the accuracy of the MD simulation largely depends on the accuracy of the force field. In this paper, we compared the structural ensembles of the activation domain 1 (AD1) in p53 tumor suppressor obtained from the widely used force fields, AMBER99SB-ILDN, CHARMM27, CHARMM36m with different water models. The results show that CHARMM36m generates more extended conformations than other force fields, while CHARMM27 prefers to sample the [Formula: see text]-helical structure. Moreover, the chemical shifts obtained by CHARMM36m are the closest to the experimental measurements. These results indicate that the CHARMM36m force field performs best in characterizing the structure properties of p53 AD1. Water models are also critical to describe the structural ensemble of IDPs. TIP4P water model can obtain more extended conformations and produce more local helical conformations than the TIP3P model in our simulation. In addition, we also compare the chemical shifts predicted by different chemical shift predicting programs with experimental measurements, the results show that SHIFTX2 obtains the best performance in the chemical shifts prediction.
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Affiliation(s)
- Shangbo Ning
- School of Biology and Pharmceutical Pharmaceutical Engineering, Wuhan Polytechnic University, Wuhan 430023, P. R. China
| | - Jun Liu
- School of Biology and Pharmceutical Pharmaceutical Engineering, Wuhan Polytechnic University, Wuhan 430023, P. R. China
| | - Na Liu
- School of Biology and Pharmceutical Pharmaceutical Engineering, Wuhan Polytechnic University, Wuhan 430023, P. R. China
| | - Dazhong Yan
- School of Biology and Pharmceutical Pharmaceutical Engineering, Wuhan Polytechnic University, Wuhan 430023, P. R. China
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14
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Xia Y, Wang L, Ma X, Li X. Investigation on the Genomic Characterization of Uterine Sarcoma for rAd- p53 Combined with Chemotherapy Treatment. Hum Gene Ther 2020; 31:881-890. [PMID: 32013587 DOI: 10.1089/hum.2019.305] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023] Open
Abstract
The aim is to investigate the genomic characterization of uterine sarcoma for rAd-p53 (Gendicine®) combined with chemotherapy treatment. We recently published an article on 12 cases of uterine sarcomas, which were treated with rAd-p53 combined with chemotherapy. We found that rAd-p53 combined with chemotherapy is effective for various uterine sarcomas. Pretreatment pathological specimens of four uterine sarcoma patients were collected from the above recent clinical research and numbered 1-4A/B. Tumor samples were subjected to targeted sequencing by using a 416 genes panel. We profiled the mutation spectrum and tumor mutation burden in the tumors, identified mutated genes, and explored their gene function. We also verified the p53 protein expression using immunohistochemistry. We identified a total of 30 mutated genes that were found from the next-generation sequencing test results. The average number of mutated genes was up to seven in the five samples. TP53 gene was mutated in two of the four patients, No. 1 and No. 4B. They are c.C833G (p.P278R) missense mutation and a point mutation (C141*) that result in a premature stop codon. We did not find a mutated TP53 gene in the other two cases, but we identified mutated genes, including CREBBP, LYN, CDKN2A, and JAK2, which were located upstream of the TP53 gene; they may have an impact on TP53. We also identified 11 additional genes which are involved in p53-related signaling pathways or have interaction with p53. Compared to solid tumor mutational burden (TMB) distribution, none of their TMB was ranking in the top 25%. Mutant p53 protein expression was positive in two specimens. Our results demonstrated that the TP53 signaling pathway plays an important role in uterine sarcoma tumorigenesis. TP53 and the upstream genes such as CREBBP, LYN, CDKN2A, and JAK2 may be involved in the genomic characterization for rAd-p53 (Gendicine) combined with chemotherapy in uterine sarcoma. Besides, the average amount of mutated genes from every patient is large.
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Affiliation(s)
- Yu Xia
- Department of Obstetrics and Gynecology, Shengjing Hospital of China Medical University, Shenyang, China
| | - Lei Wang
- Department of Obstetrics and Gynecology, Shengjing Hospital of China Medical University, Shenyang, China
| | - Xiaolin Ma
- Department of Obstetrics and Gynecology, Shengjing Hospital of China Medical University, Shenyang, China
| | - Xiuqin Li
- Department of Obstetrics and Gynecology, Shengjing Hospital of China Medical University, Shenyang, China
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15
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Venkitaraman AR. How do mutations affecting the breast cancer genes BRCA1 and BRCA2 cause cancer susceptibility? DNA Repair (Amst) 2019; 81:102668. [PMID: 31337537 PMCID: PMC6765401 DOI: 10.1016/j.dnarep.2019.102668] [Citation(s) in RCA: 52] [Impact Index Per Article: 10.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
The inheritance of monoallelic germline mutations affecting BRCA1 or BRCA2 predisposes with a high penetrance to several forms of epithelial malignancy. The large, nuclear-localized BRCA proteins act as custodians of chromosome integrity through distinct functions in the assembly and activity of macromolecular complexes that mediate DNA repair, replication reactivation and mitotic progression. The loss of these tumour suppressive functions following biallelic BRCA gene inactivation has long been thought to provoke genomic instability and carcinogenesis. However, recent studies not only identify new functions for BRCA1 and BRCA2 in the regulation of transcription and RNA processing potentially relevant to their tumour suppressive activity, but also suggest that monoallelic BRCA2 gene mutations suffice for carcinogenesis. This emerging evidence opens fresh lines of enquiry concerning tissue-specific cancer evolution in BRCA mutation carriers. Collectively, these insights engender new models to explain how BRCA gene mutations cause cancer susceptibility in specific tissues.
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Affiliation(s)
- Ashok R Venkitaraman
- Medical Research Council Cancer Unit, University of Cambridge, Box 197, Cambridge Biomedical Campus, Hills Road, Cambridge CB2 0XZ, United Kingdom.
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16
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Nbn-Mre11 interaction is required for tumor suppression and genomic integrity. Proc Natl Acad Sci U S A 2019; 116:15178-15183. [PMID: 31285322 DOI: 10.1073/pnas.1905305116] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022] Open
Abstract
We derived a mouse model in which a mutant form of Nbn/Nbs1mid8 (hereafter Nbnmid8) exhibits severely impaired binding to the Mre11-Rad50 core of the Mre11 complex. The Nbn mid8 allele was expressed exclusively in hematopoietic lineages (in Nbn -/mid8vav mice). Unlike Nbn flox/floxvav mice with Nbn deficiency in the bone marrow, Nbn -/mid8vav mice were viable. Nbn -/mid8vav mice hematopoiesis was profoundly defective, exhibiting reduced cellularity of thymus and bone marrow, and stage-specific blockage of B cell development. Within 6 mo, Nbn -/mid8 mice developed highly penetrant T cell leukemias. Nbn -/mid8vav leukemias recapitulated mutational features of human T cell acute lymphoblastic leukemia (T-ALL), containing mutations in NOTCH1, TP53, BCL6, BCOR, and IKZF1, suggesting that Nbn mid8 mice may provide a venue to examine the relationship between the Mre11 complex and oncogene activation in the hematopoietic compartment. Genomic analysis of Nbn -/mid8vav malignancies showed focal amplification of 9qA2, causing overexpression of MRE11 and CHK1 We propose that overexpression of MRE11 compensates for the metastable Mre11-Nbnmid8 interaction, and that selective pressure for overexpression reflects the essential role of Nbn in promoting assembly and activity of the Mre11 complex.
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17
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Zhao D, Lu K, Liu G, Ma L, Zhu H, He J. Design and synthesis of
BRC
analogous peptides and their interactions with a key p53 peptide. FEBS Lett 2018; 592:3438-3445. [DOI: 10.1002/1873-3468.13256] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2018] [Revised: 09/03/2018] [Accepted: 09/17/2018] [Indexed: 11/11/2022]
Affiliation(s)
- Dongxin Zhao
- College of Chemistry, Chemical and Environmental Engineering Henan University of Technology Zhengzhou China
| | - Kui Lu
- College of Chemistry, Chemical and Environmental Engineering Henan University of Technology Zhengzhou China
- School of Chemical Engineering and Food Science Zhengzhou Institute of Technology China
| | - Guangbin Liu
- College of Chemistry and Molecular Engineering Zhengzhou University China
| | - Li Ma
- College of Chemistry, Chemical and Environmental Engineering Henan University of Technology Zhengzhou China
| | - Hanjing Zhu
- College of Chemistry, Chemical and Environmental Engineering Henan University of Technology Zhengzhou China
| | - Juan He
- College of Chemistry, Chemical and Environmental Engineering Henan University of Technology Zhengzhou China
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18
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Pan Y, Li P, Jia R, Wang M, Yin Z, Cheng A. Regulation of Apoptosis During Porcine Circovirus Type 2 Infection. Front Microbiol 2018; 9:2086. [PMID: 30233552 PMCID: PMC6131304 DOI: 10.3389/fmicb.2018.02086] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2018] [Accepted: 08/15/2018] [Indexed: 12/19/2022] Open
Abstract
Apoptosis, an indispensable innate immune mechanism, regulates cellular homeostasis by removing unnecessary or damaged cells. It contains three signaling pathways: the mitochondria-mediated pathway, the death receptor pathway and the endoplasmic reticulum pathway. The importance of apoptosis in host defenses is stressed by the observation that multiple viruses have evolved various strategies to inhibit apoptosis, thereby blunting the host immune responses and promoting viral propagation. Porcine Circovirus type 2 (PCV2) utilizes various strategies to induce or inhibit programmed cell death. In this article, we review the latest research progress of the apoptosis mechanisms during infection with PCV2, including several proteins of PCV2 regulate apoptosis via interacting with host proteins and multiple signaling pathways involved in PCV2-induced apoptosis, which provides scientific basis for the pathogenesis and prevention of PCV2.
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Affiliation(s)
- Yuhong Pan
- Research Center of Avian Disease, College of Veterinary Medicine, Sichuan Agricultural University, Chengdu, China
- Institute of Preventive Veterinary Medicine, Sichuan Agricultural University, Chengdu, China
- Key Laboratory of Animal Disease and Human Health of Sichuan Province, Chengdu, China
| | - Pengfei Li
- Research Center of Avian Disease, College of Veterinary Medicine, Sichuan Agricultural University, Chengdu, China
- Institute of Preventive Veterinary Medicine, Sichuan Agricultural University, Chengdu, China
- Key Laboratory of Animal Disease and Human Health of Sichuan Province, Chengdu, China
| | - Renyong Jia
- Research Center of Avian Disease, College of Veterinary Medicine, Sichuan Agricultural University, Chengdu, China
- Institute of Preventive Veterinary Medicine, Sichuan Agricultural University, Chengdu, China
- Key Laboratory of Animal Disease and Human Health of Sichuan Province, Chengdu, China
| | - Mingshu Wang
- Research Center of Avian Disease, College of Veterinary Medicine, Sichuan Agricultural University, Chengdu, China
- Institute of Preventive Veterinary Medicine, Sichuan Agricultural University, Chengdu, China
- Key Laboratory of Animal Disease and Human Health of Sichuan Province, Chengdu, China
| | - Zhongqiong Yin
- Key Laboratory of Animal Disease and Human Health of Sichuan Province, Chengdu, China
| | - Anchun Cheng
- Research Center of Avian Disease, College of Veterinary Medicine, Sichuan Agricultural University, Chengdu, China
- Institute of Preventive Veterinary Medicine, Sichuan Agricultural University, Chengdu, China
- Key Laboratory of Animal Disease and Human Health of Sichuan Province, Chengdu, China
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19
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Eukaryotic transcription factors: paradigms of protein intrinsic disorder. Biochem J 2017; 474:2509-2532. [DOI: 10.1042/bcj20160631] [Citation(s) in RCA: 81] [Impact Index Per Article: 11.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2017] [Revised: 04/19/2017] [Accepted: 05/05/2017] [Indexed: 12/17/2022]
Abstract
Gene-specific transcription factors (TFs) are key regulatory components of signaling pathways, controlling, for example, cell growth, development, and stress responses. Their biological functions are determined by their molecular structures, as exemplified by their structured DNA-binding domains targeting specific cis-acting elements in genes, and by the significant lack of fixed tertiary structure in their extensive intrinsically disordered regions. Recent research in protein intrinsic disorder (ID) has changed our understanding of transcriptional activation domains from ‘negative noodles’ to ID regions with function-related, short sequence motifs and molecular recognition features with structural propensities. This review focuses on molecular aspects of TFs, which represent paradigms of ID-related features. Through specific examples, we review how the ID-associated flexibility of TFs enables them to participate in large interactomes, how they use only a few hydrophobic residues, short sequence motifs, prestructured motifs, and coupled folding and binding for their interactions with co-activators, and how their accessibility to post-translational modification affects their interactions. It is furthermore emphasized how classic biochemical concepts like allostery, conformational selection, induced fit, and feedback regulation are undergoing a revival with the appreciation of ID. The review also describes the most recent advances based on computational simulations of ID-based interaction mechanisms and structural analysis of ID in the context of full-length TFs and suggests future directions for research in TF ID.
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20
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Domankevich V, Opatowsky Y, Malik A, Korol AB, Frenkel Z, Manov I, Avivi A, Shams I. Adaptive patterns in the p53 protein sequence of the hypoxia- and cancer-tolerant blind mole rat Spalax. BMC Evol Biol 2016; 16:177. [PMID: 27590526 PMCID: PMC5010716 DOI: 10.1186/s12862-016-0743-8] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2015] [Accepted: 08/17/2016] [Indexed: 12/19/2022] Open
Abstract
Background The subterranean blind mole rat, Spalax (genus Nannospalax) endures extreme hypoxic conditions and fluctuations in oxygen levels that threaten DNA integrity. Nevertheless, Spalax is long-lived, does not develop spontaneous cancer, and exhibits an outstanding resistance to carcinogenesis in vivo, as well as anti-cancer capabilities in vitro. We hypothesized that adaptations to similar extreme environmental conditions involve common mechanisms for overcoming stress-induced DNA damage. Therefore, we aimed to identify shared features among species that are adapted to hypoxic stress in the sequence of the tumor-suppressor protein p53, a master regulator of the DNA-damage response (DDR). Results We found that the sequences of p53 transactivation subdomain 2 (TAD2) and tetramerization and regulatory domains (TD and RD) are more similar among hypoxia-tolerant species than expected from phylogeny. Specific positions in these domains composed patterns that are more frequent in hypoxia-tolerant species and have proven to be good predictors of species’ classification into stress-related categories. Some of these positions, which are known to be involved in the interactions between p53 and critical DDR proteins, were identified as positively selected. By 3D modeling of p53 interactions with the coactivator p300 and the DNA repair protein RPA70, we demonstrated that, compared to humans, these substitutions potentially reduce the binding of these proteins to Spalax p53. Conclusions We conclude that extreme hypoxic conditions may have led to convergent evolutionary adaptations of the DDR via TAD2 and TD/RD domains of p53. Electronic supplementary material The online version of this article (doi:10.1186/s12862-016-0743-8) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Vered Domankevich
- Institute of Evolution & Department of Evolutionary and Environmental Biology, University of Haifa, Haifa, Israel
| | - Yarden Opatowsky
- Mina and Everard Goodman Faculty of Life Sciences and Advanced Materials and Nanotechnology Institute, Bar-Ilan University, Ramat-Gan, Israel
| | - Assaf Malik
- Institute of Evolution & Department of Evolutionary and Environmental Biology, University of Haifa, Haifa, Israel
| | - Abraham B Korol
- Institute of Evolution & Department of Evolutionary and Environmental Biology, University of Haifa, Haifa, Israel
| | - Zeev Frenkel
- Institute of Evolution & Department of Evolutionary and Environmental Biology, University of Haifa, Haifa, Israel
| | - Irena Manov
- Institute of Evolution & Department of Evolutionary and Environmental Biology, University of Haifa, Haifa, Israel
| | - Aaron Avivi
- Institute of Evolution & Department of Evolutionary and Environmental Biology, University of Haifa, Haifa, Israel
| | - Imad Shams
- Institute of Evolution & Department of Evolutionary and Environmental Biology, University of Haifa, Haifa, Israel.
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21
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Martinez JS, Baldeyron C, Carreira A. Molding BRCA2 function through its interacting partners. Cell Cycle 2016; 14:3389-95. [PMID: 26566862 DOI: 10.1080/15384101.2015.1093702] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022] Open
Abstract
The role of the tumor suppressor BRCA2 has been shaped over 2 decades thanks to the discovery of its protein and nucleic acid partners, biochemical and structural studies of the protein, and the functional evaluation of germline variants identified in breast cancer patients. Yet, the pathogenic and functional effect of many germline mutations in BRCA2 remains undetermined, and the heterogeneity of BRCA2-associated tumors challenges the identification of causative variants that drive tumorigenesis. In this review, we propose an overview of the established and emerging interacting partners and functional pathways attributed to BRCA2, and we speculate on how variants altering these functions may contribute to cancer susceptibility.
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Affiliation(s)
- Juan S Martinez
- a Institut Curie; Centre de Recherche ; Orsay , France.,b CNRS UMR3348; Genotoxic Stress and Cancer; Centre Universitaire ; Orsay , France
| | - Céline Baldeyron
- a Institut Curie; Centre de Recherche ; Orsay , France.,b CNRS UMR3348; Genotoxic Stress and Cancer; Centre Universitaire ; Orsay , France
| | - Aura Carreira
- a Institut Curie; Centre de Recherche ; Orsay , France.,b CNRS UMR3348; Genotoxic Stress and Cancer; Centre Universitaire ; Orsay , France
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22
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Chipps E, Protzman A, Muhi MZ, Ando S, Calvet JP, Islam MR. Nuclear Localization Signal and p53 Binding Site in MAP/ERK Kinase Kinase 1 (MEKK1). J Cell Biochem 2016; 116:2903-14. [PMID: 26018553 DOI: 10.1002/jcb.25238] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2014] [Accepted: 05/19/2015] [Indexed: 12/18/2022]
Abstract
Previously, we showed that Mekk1 translocates to the nucleus, interacts with tumor suppressor protein p53, and co-represses PKD1 transcription via an atypical p53 binding site on the minimal PKD1 promoter (JBC 285:38,818-38,831, 2010). In this study, we report the mechanisms of Mekk1 nuclear transport and p53 binding. Using GFP-linked constitutively active-Mekk1 (CA-Mekk1) and a deletion strategy, we identified a nuclear localization signal (HRDVK) located at amino acid (aa) residues 1,349-1,353 in the C-terminal Mekk1 catalytic domain. Deletion of this sequence in CA-Mekk1 and full-length Mekk1 significantly reduced their nuclear translocation in both HEK293T and COS-1 cells. Using co-immunoprecipitation, we identified an adjacent sequence (GANLID, aa 1,354-1,360) in Mekk1 responsible for p53 binding. Deletion of this sequence markedly reduced the interaction of Mekk1 with p53. Mekk1 does not appear to affect phosphorylation of Ser15, located in the Mdm2 interaction site, or other Ser residues in p53. However, Mekk1 mediates p53 protein stability in the presence of Mdm2 and reduces p53 ubiquitination, suggesting an interference with Mdm2-mediated degradation of p53 by the ubiquitin-proteasome pathway.
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Affiliation(s)
- Elizabeth Chipps
- Laboratory of Biochemistry, Garrett-Strong Science Building 3100, 800 University Drive, Northwest Missouri State University, Maryville, Missouri, 64468
| | - April Protzman
- Laboratory of Biochemistry, Garrett-Strong Science Building 3100, 800 University Drive, Northwest Missouri State University, Maryville, Missouri, 64468
| | - M Zubayed Muhi
- Laboratory of Biochemistry, Garrett-Strong Science Building 3100, 800 University Drive, Northwest Missouri State University, Maryville, Missouri, 64468
| | - Shoko Ando
- Laboratory of Biochemistry, Garrett-Strong Science Building 3100, 800 University Drive, Northwest Missouri State University, Maryville, Missouri, 64468
| | - James P Calvet
- Department of Biochemistry and Molecular Biology and the Kidney Institute, University of Kansas Medical Center, Kansas City, Kansas, 66160
| | - M Rafiq Islam
- Laboratory of Biochemistry, Garrett-Strong Science Building 3100, 800 University Drive, Northwest Missouri State University, Maryville, Missouri, 64468
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23
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Acedo A, Hernández-Moro C, Curiel-García Á, Díez-Gómez B, Velasco EA. Functional classification of BRCA2 DNA variants by splicing assays in a large minigene with 9 exons. Hum Mutat 2015; 36:210-21. [PMID: 25382762 PMCID: PMC4371643 DOI: 10.1002/humu.22725] [Citation(s) in RCA: 43] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2014] [Accepted: 10/27/2014] [Indexed: 01/04/2023]
Abstract
Numerous pathogenic DNA variants impair the splicing mechanism in human genetic diseases. Minigenes are optimal approaches to test variants under the splicing viewpoint without the need of patient samples. We aimed to design a robust minigene construct of the breast cancer gene BRCA2 in order to investigate the impact of variants on splicing. BRCA2 exons 19-27 (MGBR2_ex19-27) were cloned in the new vector pSAD. It produced a large transcript of the expected size (2,174 nucleotides) and exon structure (V1-ex19-27-V2). Splicing assays showed that 18 (17 splice-site and 1 silencer variants) out of 40 candidate DNA variants induced aberrant patterns. Twenty-four anomalous transcripts were accurately detected by fluorescent-RT-PCR that were generated by exon-skipping, alternative site usage, and intron-retention events. Fourteen variants induced major anomalies and were predicted to disrupt protein function so they could be classified as pathogenic. Furthermore, minigene mimicked previously reported patient RNA outcomes of seven variants supporting the reproducibility of minigene assays. Therefore, a relevant fraction of variants are involved in breast cancer through splicing alterations. MGBR2_ex19-27 is the largest reported BRCA2 minigene and constitutes a valuable tool for the functional and clinical classification of sequence variations.
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Affiliation(s)
- Alberto Acedo
- Splicing and Genetic Susceptibility to Cancer, Instituto de Biología y Genética Molecular (CSIC-UVa), Valladolid, Spain
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24
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Biesma HD, Schouten PC, Lacle MM, Sanders J, Brugman W, Kerkhoven R, Mandjes I, van der Groep P, van Diest PJ, Linn SC. Copy number profiling by array comparative genomic hybridization identifies frequently occurring BRCA2-like male breast cancer. Genes Chromosomes Cancer 2015; 54:734-44. [DOI: 10.1002/gcc.22284] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2015] [Accepted: 06/25/2015] [Indexed: 11/08/2022] Open
Affiliation(s)
- Hedde D. Biesma
- Department of Molecular Pathology; Netherlands Cancer Institute; Amsterdam The Netherlands
| | - Philip C. Schouten
- Department of Molecular Pathology; Netherlands Cancer Institute; Amsterdam The Netherlands
| | - Miangela M. Lacle
- Department of Pathology; University Medical Center Utrecht; The Netherlands
| | - Joyce Sanders
- Department of Pathology; Netherlands Cancer Institute; Amsterdam The Netherlands
| | - Wim Brugman
- Genomics Core Facility, Netherlands Cancer Institute; Amsterdam The Netherlands
| | - Ron Kerkhoven
- Genomics Core Facility, Netherlands Cancer Institute; Amsterdam The Netherlands
| | - Ingrid Mandjes
- Data Center, Netherlands Cancer Institute; Amsterdam The Netherlands
| | | | - Paul J. van Diest
- Department of Pathology; University Medical Center Utrecht; The Netherlands
| | - Sabine C. Linn
- Department of Molecular Pathology; Netherlands Cancer Institute; Amsterdam The Netherlands
- Department of Pathology; University Medical Center Utrecht; The Netherlands
- Department of Medical Oncology; Netherlands Cancer Institute; Amsterdam The Netherlands
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25
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Uversky VN, Davé V, Iakoucheva LM, Malaney P, Metallo SJ, Pathak RR, Joerger AC. Pathological unfoldomics of uncontrolled chaos: intrinsically disordered proteins and human diseases. Chem Rev 2014; 114:6844-79. [PMID: 24830552 PMCID: PMC4100540 DOI: 10.1021/cr400713r] [Citation(s) in RCA: 196] [Impact Index Per Article: 19.6] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
Affiliation(s)
- Vladimir N. Uversky
- Department of Molecular Medicine and USF Health Byrd Alzheimer’s Research Institute University of South Florida, Tampa, Florida 33612, United States
- Institute for Biological Instrumentation, Russian Academy of Sciences, 142290 Pushchino, Moscow Region, Russia
- Department of Biological Sciences, Faculty of Science, King Abdulaziz University, Jeddah 22254, Saudi Arabia
| | - Vrushank Davé
- Department of Pathology and Cell Biology , Morsani College of Medicine, University of South Florida, Tampa, Florida 33612, United States
- Department of Molecular Oncology, H. Lee Moffitt Cancer Center and Research Institute, Tampa, Florida 33612, United States
| | - Lilia M. Iakoucheva
- Department of Psychiatry, University of California San Diego, La Jolla, California 92093, United States
| | - Prerna Malaney
- Department of Pathology and Cell Biology , Morsani College of Medicine, University of South Florida, Tampa, Florida 33612, United States
| | - Steven J. Metallo
- Department of Chemistry, Georgetown University, Washington, District of Columbia 20057, United States
| | - Ravi Ramesh Pathak
- Department of Pathology and Cell Biology , Morsani College of Medicine, University of South Florida, Tampa, Florida 33612, United States
| | - Andreas C. Joerger
- Medical Research Council Laboratory of Molecular Biology, Francis Crick Avenue, Cambridge CB2 0QH, United Kingdom
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26
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Guaragnella N, Marra E, Galli A, Moro L, Giannattasio S. Silencing of BRCA2 decreases anoikis and its heterologous expression sensitizes yeast cells to acetic acid-induced programmed cell death. Apoptosis 2014; 19:1330-41. [DOI: 10.1007/s10495-014-1006-z] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
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27
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Lee DH, Ha JH, Kim Y, Jang M, Park SJ, Yoon HS, Kim EH, Bae KH, Park BC, Park SG, Yi GS, Chi SW. A conserved mechanism for binding of p53 DNA-binding domain and anti-apoptotic Bcl-2 family proteins. Mol Cells 2014; 37:264-9. [PMID: 24646834 PMCID: PMC3969048 DOI: 10.14348/molcells.2014.0001] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/03/2014] [Accepted: 01/14/2014] [Indexed: 01/12/2023] Open
Abstract
The molecular interaction between tumor suppressor p53 and the anti-apoptotic Bcl-2 family proteins plays an essential role in the transcription-independent apoptotic pathway of p53. In this study, we investigated the binding of p53 DNA-binding domain (p53DBD) with the anti-apoptotic Bcl-2 family proteins, Bcl-w, Mcl-1, and Bcl-2, using GST pull-down assay and NMR spectroscopy. The GST pull-down assays and NMR experiments demonstrated the direct binding of the p53DBD with Bcl-w, Mcl-1, and Bcl-2. Further, NMR chemical shift perturbation data showed that Bcl-w and Mcl-1 bind to the positively charged DNA-binding surface of p53DBD. Noticeably, the refined structural models of the complexes between p53DBD and Bcl-w, Mcl-1, and Bcl-2 showed that the binding mode of p53DBD is highly conserved among the anti-apoptotic Bcl-2 family proteins. Furthermore, the chemical shift perturbations on Bcl-w, Mcl-1, and Bcl-2 induced by p53DBD binding occurred not only at the p53DBD-binding acidic region but also at the BH3 peptide-binding pocket, which suggests an allosteric conformational change similar to that observed in Bcl-XL. Taken altogether, our results revealed a structural basis for a conserved binding mechanism between p53DBD and the anti-apoptotic Bcl-2 family proteins, which shed light on to the molecular understanding of the transcription-independent apoptosis pathway of p53.
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Affiliation(s)
- Dong-Hwa Lee
- Medical Proteomics Research Center, Korea Research Institute of Bioscience and Biotechnology, Daejeon 305-806,
Korea
| | - Ji-Hyang Ha
- Medical Proteomics Research Center, Korea Research Institute of Bioscience and Biotechnology, Daejeon 305-806,
Korea
| | - Yul Kim
- Department of Bio and Brain Engineering, Korea Advanced Institute for Science and Technology, Daejeon 305-701,
Korea
| | - Mi Jang
- Medical Proteomics Research Center, Korea Research Institute of Bioscience and Biotechnology, Daejeon 305-806,
Korea
| | - Sung Jean Park
- College of Pharmacy, Gachon University, Incheon 406-799,
Korea
| | - Ho Sup Yoon
- Division of Structural Biology and Biochemistry, School of Biological Sciences, Nanyang Technological University, Singapore 637511,
Singapore
| | - Eun-Hee Kim
- Division of Magnetic Resonance, Korea Basic Science Institute, Cheongwon 363-883,
Korea
| | - Kwang-Hee Bae
- Research Center for Integrated Cellulomics, Korea Research Institute of Bioscience and Biotechnology, Daejeon 305-806,
Korea
| | - Byoung Chul Park
- Medical Proteomics Research Center, Korea Research Institute of Bioscience and Biotechnology, Daejeon 305-806,
Korea
| | - Sung Goo Park
- Medical Proteomics Research Center, Korea Research Institute of Bioscience and Biotechnology, Daejeon 305-806,
Korea
| | - Gwan-Su Yi
- Department of Bio and Brain Engineering, Korea Advanced Institute for Science and Technology, Daejeon 305-701,
Korea
| | - Seung-Wook Chi
- Medical Proteomics Research Center, Korea Research Institute of Bioscience and Biotechnology, Daejeon 305-806,
Korea
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28
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Magwood AC, Malysewich MJ, Cealic I, Mundia MM, Knapp J, Baker MD. Endogenous levels of Rad51 and Brca2 are required for homologous recombination and regulated by homeostatic re-balancing. DNA Repair (Amst) 2013; 12:1122-33. [PMID: 24210700 DOI: 10.1016/j.dnarep.2013.10.006] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2013] [Accepted: 10/15/2013] [Indexed: 12/17/2022]
Abstract
Stable expression of Rad51 siRNA was used to generate mouse hybridoma cell lines in which endogenous Rad51 levels were depleted by as much as 60%. Stable Rad51 knockdowns feature reduced homologous recombination responses. The relative ease with which stable Rad51 knockdowns were recovered was surprising, given the embryonic lethality of Rad51 ablation. Interestingly, Rad51-depleted hybridoma cell lines are characterized by reduced levels of p53 protein. Completely unexpected, was the finding that Rad51-depleted hybridoma cell lines are also reduced for the breast cancer susceptibility 2 (Brca2) protein. Additionally, hybridoma cell lines that are siRNA depleted for mouse Brca2 show a corresponding reduction in Rad51 and p53 proteins. Furthermore, cellular levels of Rad51, Brca2 and p53 can be elevated in these cell lines by ectopic expression of wild-type human Rad51 and wild-type human BRCA2. In marked contrast, hybridoma cell lines that are siRNA depleted for mouse p53 feature relatively normal Rad51 and Brca2 levels. These results suggest that cellular levels of Brca2 and Rad51 are mutually dependent on each other, and that low levels of these proteins provide selective pressure for reduction of p53, which permits cell growth.
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Affiliation(s)
- Alissa C Magwood
- Department of Molecular and Cellular Biology, College of Biological Science, University of Guelph, Guelph, Ontario, N1G 2W1, Canada
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29
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Verma S, Rao BJ. p53 suppresses BRCA2-stimulated ATPase and strand exchange functions of human RAD51. J Biochem 2013; 154:237-48. [PMID: 23678008 DOI: 10.1093/jb/mvt040] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
Although homologous recombination (HR) is an important pathway for DNA repair, it can also be a cause for deleterious genomic rearrangements leading to carcinogenesis. Therefore, cells have evolved elaborate mechanisms to regulate HR, positively as well as negatively. Among many molecular components that regulate HR are tumour suppressors p53, a negative regulator and breast cancer early-onset (BRCA)2, a positive regulator. Both the players not only interact with each other but also directly interact with human RAD51 (hRAD51), the key recombinase in HR. Here, for the first time we studied HR regulation by the combined action of p53 and BRCA2, in vitro. While BRC4 peptide inhibits ATP hydrolysis by hRAD51, BRCA2(BRC1-8) stimulates DNA-independent and double-stranded DNA-dependent ATPase several fold and only marginally single-stranded DNA-dependent ATPase. Pull down assays demonstrated the occurrence of complex comprising of all three proteins and DNA, where p53 tends to compete out hRAD51 and BRCA2(BRC1-8), leading to not only the decline in ATP hydrolysis but also the strand exchange function of hRAD51 that was stimulated by BRCA2(BRC1-8). Our findings suggest a rigorous p53-mediated regulation on hRAD51 functions in HR even in the presence of BRCA2.
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Affiliation(s)
- Shalini Verma
- Department of Biological Sciences, Tata Institute of Fundamental Research, Homi Bhabha Road, Mumbai 400 005, Maharashtra, India
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Mladenov E, Magin S, Soni A, Iliakis G. DNA double-strand break repair as determinant of cellular radiosensitivity to killing and target in radiation therapy. Front Oncol 2013; 3:113. [PMID: 23675572 PMCID: PMC3650303 DOI: 10.3389/fonc.2013.00113] [Citation(s) in RCA: 191] [Impact Index Per Article: 17.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2013] [Accepted: 04/24/2013] [Indexed: 12/29/2022] Open
Abstract
Radiation therapy plays an important role in the management of a wide range of cancers. Besides innovations in the physical application of radiation dose, radiation therapy is likely to benefit from novel approaches exploiting differences in radiation response between normal and tumor cells. While ionizing radiation induces a variety of DNA lesions, including base damages and single-strand breaks, the DNA double-strand break (DSB) is widely considered as the lesion responsible not only for the aimed cell killing of tumor cells, but also for the general genomic instability that leads to the development of secondary cancers among normal cells. Homologous recombination repair (HRR), non-homologous end-joining (NHEJ), and alternative NHEJ, operating as a backup, are the major pathways utilized by cells for the processing of DSBs. Therefore, their function represents a major mechanism of radiation resistance in tumor cells. HRR is also required to overcome replication stress – a potent contributor to genomic instability that fuels cancer development. HRR and alternative NHEJ show strong cell-cycle dependency and are likely to benefit from radiation therapy mediated redistribution of tumor cells throughout the cell-cycle. Moreover, the synthetic lethality phenotype documented between HRR deficiency and PARP inhibition has opened new avenues for targeted therapies. These observations make HRR a particularly intriguing target for treatments aiming to improve the efficacy of radiation therapy. Here, we briefly describe the major pathways of DSB repair and review their possible contribution to cancer cell radioresistance. Finally, we discuss promising alternatives for targeting DSB repair to improve radiation therapy and cancer treatment.
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Affiliation(s)
- Emil Mladenov
- Institute of Medical Radiation Biology, University of Duisburg-Essen Medical School Essen, Germany
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Ha JH, Shin JS, Yoon MK, Lee MS, He F, Bae KH, Yoon HS, Lee CK, Park SG, Muto Y, Chi SW. Dual-site interactions of p53 protein transactivation domain with anti-apoptotic Bcl-2 family proteins reveal a highly convergent mechanism of divergent p53 pathways. J Biol Chem 2013; 288:7387-98. [PMID: 23316052 DOI: 10.1074/jbc.m112.400754] [Citation(s) in RCA: 40] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/24/2023] Open
Abstract
Molecular interactions between the tumor suppressor p53 and the anti-apoptotic Bcl-2 family proteins play an important role in the transcription-independent apoptosis of p53. The p53 transactivation domain (p53TAD) contains two conserved ΦXXΦΦ motifs (Φ indicates a bulky hydrophobic residue and X is any other residue) referred to as p53TAD1 (residues 15-29) and p53TAD2 (residues 39-57). We previously showed that p53TAD1 can act as a binding motif for anti-apoptotic Bcl-2 family proteins. In this study, we have identified p53TAD2 as a binding motif for anti-apoptotic Bcl-2 family proteins by using NMR spectroscopy, and we calculated the structures of Bcl-X(L)/Bcl-2 in complex with the p53TAD2 peptide. NMR chemical shift perturbation data showed that p53TAD2 peptide binds to diverse members of the anti-apoptotic Bcl-2 family independently of p53TAD1, and the binding between p53TAD2 and p53TAD1 to Bcl-X(L) is competitive. Refined structural models of the Bcl-X(L)·p53TAD2 and Bcl-2·p53TAD2 complexes showed that the binding sites occupied by p53TAD2 in Bcl-X(L) and Bcl-2 overlap well with those occupied by pro-apoptotic BH3 peptides. Taken together with the mutagenesis, isothermal titration calorimetry, and paramagnetic relaxation enhancement data, our structural comparisons provided the structural basis of p53TAD2-mediated interaction with the anti-apoptotic proteins, revealing that Bcl-X(L)/Bcl-2, MDM2, and cAMP-response element-binding protein-binding protein/p300 share highly similar modes of binding to the dual p53TAD motifs, p53TAD1 and p53TAD2. In conclusion, our results suggest that the dual-site interaction of p53TAD is a highly conserved mechanism underlying target protein binding in the transcription-dependent and transcription-independent apoptotic pathways of p53.
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Affiliation(s)
- Ji-Hyang Ha
- Medical Proteomics Research Center, Korea Research Institute of Bioscience and Biotechnology, Daejeon 305-806, Republic of Korea
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Glanzer JG, Carnes KA, Soto P, Liu S, Parkhurst LJ, Oakley GG. A small molecule directly inhibits the p53 transactivation domain from binding to replication protein A. Nucleic Acids Res 2012; 41:2047-59. [PMID: 23267009 PMCID: PMC3561959 DOI: 10.1093/nar/gks1291] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/24/2023] Open
Abstract
Replication protein A (RPA), essential for DNA replication, repair and DNA damage signalling, possesses six ssDNA-binding domains (DBDs), including DBD-F on the N-terminus of the largest subunit, RPA70. This domain functions as a binding site for p53 and other DNA damage and repair proteins that contain amphipathic alpha helical domains. Here, we demonstrate direct binding of both ssDNA and the transactivation domain 2 of p53 (p53TAD2) to DBD-F, as well as DBD-F-directed dsDNA strand separation by RPA, all of which are inhibited by fumaropimaric acid (FPA). FPA binds directly to RPA, resulting in a conformational shift as determined through quenching of intrinsic tryptophan fluorescence in full length RPA. Structural analogues of FPA provide insight on chemical properties that are required for inhibition. Finally, we confirm the inability of RPA possessing R41E and R43E mutations to bind to p53, destabilize dsDNA and quench tryptophan fluorescence by FPA, suggesting that protein binding, DNA modulation and inhibitor binding all occur within the same site on DBD-F. The disruption of p53–RPA interactions by FPA may disturb the regulatory functions of p53 and RPA, thereby inhibiting cellular pathways that control the cell cycle and maintain the integrity of the human genome.
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Affiliation(s)
- Jason G Glanzer
- Department of Oral Biology, College of Dentistry, University of Nebraska Medical Center, Lincoln, NE 68583, USA
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Molecular basis for modulation of the p53 target selectivity by KLF4. PLoS One 2012; 7:e48252. [PMID: 23118962 PMCID: PMC3484126 DOI: 10.1371/journal.pone.0048252] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2012] [Accepted: 09/20/2012] [Indexed: 12/15/2022] Open
Abstract
The tumour suppressor p53 controls transcription of various genes involved in apoptosis, cell-cycle arrest, DNA repair and metabolism. However, its DNA-recognition specificity is not nearly sufficient to explain binding to specific locations in vivo. Here, we present evidence that KLF4 increases the DNA-binding affinity of p53 through the formation of a loosely arranged ternary complex on DNA. This effect depends on the distance between the response elements of KLF4 and p53. Using nuclear magnetic resonance and fluorescence techniques, we found that the amino-terminal domain of p53 interacts with the KLF4 zinc fingers and mapped the interaction site. The strength of this interaction was increased by phosphorylation of the p53 N-terminus, particularly on residues associated with regulation of cell-cycle arrest genes. Taken together, the cooperative binding of KLF4 and p53 to DNA exemplifies a regulatory mechanism that contributes to p53 target selectivity.
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Magwood AC, Mundia MM, Baker MD. High levels of wild-type BRCA2 suppress homologous recombination. J Mol Biol 2012; 421:38-53. [PMID: 22579622 DOI: 10.1016/j.jmb.2012.05.007] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2011] [Revised: 04/23/2012] [Accepted: 05/03/2012] [Indexed: 11/26/2022]
Abstract
Endogenous levels of the BRCA2 (breast cancer susceptibility 2) protein promote homologous recombination by regulating the essential strand exchange protein RAD51. To examine BRCA2 function in homologous recombination, we expressed human BRCA2 in control mouse hybridoma cells, as well as those that were depleted of endogenous Brca2 by small interfering RNA. With moderate human BRCA2 expression, homologous recombination was stimulated. Conversely, a higher level of BRCA2 reduced homologous recombination and DNA-damage-induced Rad51 foci formation. Cells expressing high levels of BRCA2 feature normal growth, increased sensitivity to mitomycin C, and increased illegitimate recombination. BRCA2-overexpressing cells are also characterized by suppression of p53 transcriptional regulation and a corresponding reduction in the expression of the p53-responsive genes Noxa and p21. Notably, in cells expressing high levels of BRCA2, small interfering RNA depletion of human BRCA2 or ectopic expression of Rad51 increases homologous recombination and decreases illegitimate recombination. Thus, high levels of wild-type BRCA2 perturb Rad51-mediated homologous recombination, and relatively normal recombination responses can be restored by rebalancing recombination factors.
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Affiliation(s)
- Alissa C Magwood
- Department of Molecular and Cellular Biology, College of Biological Science, University of Guelph, Guelph, Ontario, Canada N1G 2W1
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Jenkins LMM, Durell SR, Mazur SJ, Appella E. p53 N-terminal phosphorylation: a defining layer of complex regulation. Carcinogenesis 2012; 33:1441-9. [PMID: 22505655 DOI: 10.1093/carcin/bgs145] [Citation(s) in RCA: 83] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
The p53 tumor suppressor is a critical component of the cellular response to stress. As it can inhibit cell growth, p53 is mutated or functionally inactivated in most tumors. A multitude of protein-protein interactions with transcriptional cofactors are central to p53-dependent responses. In its activated state, p53 is extensively modified in both the N- and C-terminal regions of the protein. These modifications, especially phosphorylation of serine and threonine residues in the N-terminal transactivation domain, affect p53 stability and activity by modulating the affinity of protein-protein interactions. Here, we review recent findings from in vitro and in vivo studies on the role of p53 N-terminal phosphorylation. These modifications can either positively or negatively affect p53 and add a second layer of complex regulation to the divergent interactions of the p53 transactivation domain.
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Affiliation(s)
- Lisa M Miller Jenkins
- Laboratory of Cell Biology, National Cancer Institute, NIH, 37 Convent Drive, Room 2140, Bethesda, MD 20892, USA
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Krejci L, Altmannova V, Spirek M, Zhao X. Homologous recombination and its regulation. Nucleic Acids Res 2012; 40:5795-818. [PMID: 22467216 PMCID: PMC3401455 DOI: 10.1093/nar/gks270] [Citation(s) in RCA: 456] [Impact Index Per Article: 38.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022] Open
Abstract
Homologous recombination (HR) is critical both for repairing DNA lesions in mitosis and for chromosomal pairing and exchange during meiosis. However, some forms of HR can also lead to undesirable DNA rearrangements. Multiple regulatory mechanisms have evolved to ensure that HR takes place at the right time, place and manner. Several of these impinge on the control of Rad51 nucleofilaments that play a central role in HR. Some factors promote the formation of these structures while others lead to their disassembly or the use of alternative repair pathways. In this article, we review these mechanisms in both mitotic and meiotic environments and in different eukaryotic taxa, with an emphasis on yeast and mammal systems. Since mutations in several proteins that regulate Rad51 nucleofilaments are associated with cancer and cancer-prone syndromes, we discuss how understanding their functions can lead to the development of better tools for cancer diagnosis and therapy.
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Affiliation(s)
- Lumir Krejci
- Department of Biology, Masaryk University, Brno, Czech Republic.
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Abstract
The wealth of available protein structural data provides unprecedented opportunity to study and better understand the underlying principles of protein folding and protein structure evolution. A key to achieving this lies in the ability to analyse these data and to organize them in a coherent classification scheme. Over the past years several protein classifications have been developed that aim to group proteins based on their structural relationships. Some of these classification schemes explore the concept of structural neighbourhood (structural continuum), whereas other utilize the notion of protein evolution and thus provide a discrete rather than continuum view of protein structure space. This chapter presents a strategy for classification of proteins with known three-dimensional structure. Steps in the classification process along with basic definitions are introduced. Examples illustrating some fundamental concepts of protein folding and evolution with a special focus on the exceptions to them are presented.
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Fernandez-Fernandez MR, Sot B. The relevance of protein-protein interactions for p53 function: the CPE contribution. Protein Eng Des Sel 2010; 24:41-51. [PMID: 20952436 DOI: 10.1093/protein/gzq074] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023] Open
Abstract
The relevance of p53 as a tumour suppressor is evident from the fact that more than 50% of the human cancers hold mutations in the gene coding for p53, and of the remaining cancers a considerable number have alterations in the p53 pathway. From its discovery 30 years ago, the importance of p53 as an essential transcription factor for tumour suppression has become clear. More recently, new and seemingly diverse roles of p53 have been discovered. It soon became clear that protein-protein interactions play an important role in the regulation of the p53 function at different levels. Here we review the contribution by Prof. Fersht and his group towards understanding the basis and functional relevance of p53 protein-protein interactions, and the important role that protein science, biophysics and structural biology have played in the science produced in the Centre for Protein Engineering over the years.
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Research highlights. Nat Struct Mol Biol 2010. [DOI: 10.1038/nsmb0610-678] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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