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Banks WA, Hansen KM, Erickson MA, Crews FT. High-mobility group box 1 (HMGB1) crosses the BBB bidirectionally. Brain Behav Immun 2023; 111:386-394. [PMID: 37146655 DOI: 10.1016/j.bbi.2023.04.018] [Citation(s) in RCA: 7] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/16/2021] [Revised: 04/25/2023] [Accepted: 04/30/2023] [Indexed: 05/07/2023] Open
Abstract
High-mobility group box 1 (HMGB1) is a ubiquitous protein that regulates transcription in the nucleus, and is an endogenous damage-associated molecular pattern molecule that activates the innate immune system. HMGB1 activates the TLR4 and RAGE recepto, inducing downstream signals reminiscent of cytokines that have been found to cross the blood-brain barrier (BBB). Blood HMGB1 increases in stroke, sepsis, senescence, alcohol binge drinking and other conditions. Here, we examined the ability of HMGB1 radioactively labeled with iodine (I-HMGB1) to cross the BBB. We found that I-HMGB1 readily entered into mouse brain from the circulation with a unidirectional influx rate of 0.654 μl/g-min. All brain regions tested took up I-HMGB1; uptake was greatest by the olfactory bulb and least in the striatum. Transport was not reliably inhibited by unlabeled HMGB1 nor by inhibitors of TLR4, TLR2, RAGE, or CXCR4. Uptake was enhanced by co-injection of wheatgerm agglutinin, suggestive of involvement of absorptive transcytosis as a mechanism of transport. Induction of inflammation/neuroinflammation with lipopolysaccharide is known to increase blood HMGB1; we report here that brain transport is also increased by LPS-induced inflammation. Finally, we found that I-HMGB1 was also transported in the brain-to-blood direction, with both unlabeled HMGB1 or lipopolysaccharide increasing the transport rate. These results show that HMGB1 can bidirectionally cross the BBB and that those transport rates are enhanced by inflammation. Such transport provides a mechanism by which HMGB1 levels would impact neuroimmune signaling in both the brain and periphery.
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Affiliation(s)
- William A Banks
- Geriatric Research Educational and Clinical Center, Veterans Affairs Puget Sound Health Care System, Seattle, WA, US State; Division of Gerontology and Geriatric Medicine, University of Washington School of Medicine, Seattle, WA, US State.
| | - Kim M Hansen
- Geriatric Research Educational and Clinical Center, Veterans Affairs Puget Sound Health Care System, Seattle, WA, US State; Division of Gerontology and Geriatric Medicine, University of Washington School of Medicine, Seattle, WA, US State
| | - Michelle A Erickson
- Geriatric Research Educational and Clinical Center, Veterans Affairs Puget Sound Health Care System, Seattle, WA, US State; Division of Gerontology and Geriatric Medicine, University of Washington School of Medicine, Seattle, WA, US State
| | - Fulton T Crews
- Department of Pharmacology, University of North Carolina at Chapel Hill School of Medicine, Chapel Hill, NC, US State
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2
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Michl-Holzinger P, Obermeyer S, Markusch H, Pfab A, Ettner A, Bruckmann A, Babl S, Längst G, Schwartz U, Tvardovskiy A, Jensen ON, Osakabe A, Berger F, Grasser KD. Phosphorylation of the FACT histone chaperone subunit SPT16 affects chromatin at RNA polymerase II transcriptional start sites in Arabidopsis. Nucleic Acids Res 2022; 50:5014-5028. [PMID: 35489065 PMCID: PMC9122599 DOI: 10.1093/nar/gkac293] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2021] [Revised: 04/12/2022] [Accepted: 04/19/2022] [Indexed: 12/15/2022] Open
Abstract
The heterodimeric histone chaperone FACT, consisting of SSRP1 and SPT16, contributes to dynamic nucleosome rearrangements during various DNA-dependent processes including transcription. In search of post-translational modifications that may regulate the activity of FACT, SSRP1 and SPT16 were isolated from Arabidopsis cells and analysed by mass spectrometry. Four acetylated lysine residues could be mapped within the basic C-terminal region of SSRP1, while three phosphorylated serine/threonine residues were identified in the acidic C-terminal region of SPT16. Mutational analysis of the SSRP1 acetylation sites revealed only mild effects. However, phosphorylation of SPT16 that is catalysed by protein kinase CK2, modulates histone interactions. A non-phosphorylatable version of SPT16 displayed reduced histone binding and proved inactive in complementing the growth and developmental phenotypes of spt16 mutant plants. In plants expressing the non-phosphorylatable SPT16 version we detected at a subset of genes enrichment of histone H3 directly upstream of RNA polymerase II transcriptional start sites (TSSs) in a region that usually is nucleosome-depleted. This suggests that some genes require phosphorylation of the SPT16 acidic region for establishing the correct nucleosome occupancy at the TSS of active genes.
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Affiliation(s)
- Philipp Michl-Holzinger
- Department of Cell Biology & Plant Biochemistry, Centre for Biochemistry, University of Regensburg, Universitätsstr. 31, D-93053 Regensburg, Germany
| | - Simon Obermeyer
- Department of Cell Biology & Plant Biochemistry, Centre for Biochemistry, University of Regensburg, Universitätsstr. 31, D-93053 Regensburg, Germany
| | - Hanna Markusch
- Department of Cell Biology & Plant Biochemistry, Centre for Biochemistry, University of Regensburg, Universitätsstr. 31, D-93053 Regensburg, Germany
| | - Alexander Pfab
- Department of Cell Biology & Plant Biochemistry, Centre for Biochemistry, University of Regensburg, Universitätsstr. 31, D-93053 Regensburg, Germany
| | - Andreas Ettner
- Department of Cell Biology & Plant Biochemistry, Centre for Biochemistry, University of Regensburg, Universitätsstr. 31, D-93053 Regensburg, Germany
| | - Astrid Bruckmann
- Institute for Biochemistry I, Centre for Biochemistry, University of Regensburg, Universitätsstr. 31, D-93053 Regensburg, Germany
| | - Sabrina Babl
- Institute for Biochemistry III, Centre for Biochemistry, University of Regensburg, Universitätsstr. 31, D-93053 Regensburg, Germany
| | - Gernot Längst
- Institute for Biochemistry III, Centre for Biochemistry, University of Regensburg, Universitätsstr. 31, D-93053 Regensburg, Germany
| | - Uwe Schwartz
- NGS Analysis Centre, Biology and Pre-Clinical Medicine, University of Regensburg, Universitätsstr. 31, D-93053 Regensburg, Germany
| | - Andrey Tvardovskiy
- Department of Biochemistry and Molecular Biology, VILLUM Center for Bioanalytical Sciences, University of Southern Denmark, Odense, Denmark
| | - Ole N Jensen
- Department of Biochemistry and Molecular Biology, VILLUM Center for Bioanalytical Sciences, University of Southern Denmark, Odense, Denmark
| | - Akihisa Osakabe
- Gregor Mendel Institute (GMI), Austrian Academy of Sciences, Vienna BioCenter (VBC), Dr. Bohr-Gasse 3, 1030 Vienna, Austria
| | - Frédéric Berger
- Gregor Mendel Institute (GMI), Austrian Academy of Sciences, Vienna BioCenter (VBC), Dr. Bohr-Gasse 3, 1030 Vienna, Austria
| | - Klaus D Grasser
- Department of Cell Biology & Plant Biochemistry, Centre for Biochemistry, University of Regensburg, Universitätsstr. 31, D-93053 Regensburg, Germany
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3
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Jiang L, Shao Y, Tian Y, Ouyang C, Wang X. Nuclear Alarmin Cytokines in Inflammation. J Immunol Res 2020; 2020:7206451. [PMID: 33344656 PMCID: PMC7732391 DOI: 10.1155/2020/7206451] [Citation(s) in RCA: 19] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2020] [Revised: 10/25/2020] [Accepted: 10/29/2020] [Indexed: 12/11/2022] Open
Abstract
Pathogen-associated molecular patterns (PAMPs) are some nonspecific and highly conserved molecular structures of exogenous specific microbial pathogens, whose products can be recognized by pattern recognition receptor (PRR) on innate immune cells and induce an inflammatory response. Under physiological stress, activated or damaged cells might release some endogenous proteins that can also bind to PRR and cause a harmful aseptic inflammatory response. These endogenous proteins were named damage-associated molecular patterns (DAMPs) or alarmins. Indeed, alarmins can also play a beneficial role in the tissue repair in certain environments. Besides, some alarmin cytokines have been reported to have both nuclear and extracellular effects. This group of proteins includes high-mobility group box-1 protein (HMGB1), interleukin (IL)-33, IL-1α, IL-1F7b, and IL-16. In this article, we review the involvement of nuclear alarmins such as HMGB1, IL-33, and IL-1α under physiological state or stress state and suggest a novel activity of these molecules as central initiators in the development of sterile inflammation.
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Affiliation(s)
- Lili Jiang
- Department of Rheumatology and Clinical Immunology, Jiangxi Provincial People's Hospital Affiliated to Nanchang University, Nanchang, China
| | - Yijia Shao
- Department of Rheumatology and Clinical Immunology, Jiangxi Provincial People's Hospital Affiliated to Nanchang University, Nanchang, China
| | - Yao Tian
- Department of Rheumatology and Clinical Immunology, Jiangxi Provincial People's Hospital Affiliated to Nanchang University, Nanchang, China
| | - Changsheng Ouyang
- Department of Cardiology, Jiangxi Provincial People's Hospital Affiliated to Nanchang University, Nanchang, China
| | - Xiaohua Wang
- Geriatric Medical Center, Jiangxi Provincial People's Hospital Affiliated to Nanchang University, China
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4
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Tsujita R, Tsubota M, Sekiguchi F, Kawabata A. Role of high-mobility group box 1 and its modulation by thrombomodulin/thrombin axis in neuropathic and inflammatory pain. Br J Pharmacol 2020; 178:798-812. [PMID: 32374414 DOI: 10.1111/bph.15091] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2020] [Revised: 04/16/2020] [Accepted: 04/17/2020] [Indexed: 12/15/2022] Open
Abstract
High-mobility group box 1 (HMGB1), a nuclear protein, once released to the extracellular space, facilitates pain signals as well as inflammation. Intraplantar or intraspinal application of HMGB1 elicits hyperalgesia/allodynia in rodents by activating the advanced glycosylation end-product specific receptor (receptor for advanced glycation end-products; RAGE) or Toll-like receptor 4 (TLR4). Endogenous HMGB1 derived from neurons, perineuronal cells or immune cells accumulating in the dorsal root ganglion or sensory nerves participates in somatic and visceral pain consisting of neuropathic and/or inflammatory components. Endothelial thrombomodulin (TM) and recombinant human soluble TM, TMα, markedly increase thrombin-dependent degradation of HMGB1, and systemic administration of TMα prevents and reverses various HMGB1-dependent pathological pain. Low MW compounds that directly inactivate HMGB1 or antagonize HMGB1-targeted receptors would be useful to reduce various forms of intractable pain. Thus, HMGB1 and its receptors are considered to serve as promising targets in developing novel agents to prevent or treat pathological pain. LINKED ARTICLES: This article is part of a themed issue on Neurochemistry in Japan. To view the other articles in this section visit http://onlinelibrary.wiley.com/doi/10.1111/bph.v178.4/issuetoc.
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Affiliation(s)
- Ryuichi Tsujita
- Laboratory of Pharmacology and Pathophysiology, Faculty of Pharmacy, Kindai University (formally known as Kinki University), Higashiosaka, Japan.,Project Management Department, Asahi Kasei Pharma Corporation, Tokyo, Japan
| | - Maho Tsubota
- Laboratory of Pharmacology and Pathophysiology, Faculty of Pharmacy, Kindai University (formally known as Kinki University), Higashiosaka, Japan
| | - Fumiko Sekiguchi
- Laboratory of Pharmacology and Pathophysiology, Faculty of Pharmacy, Kindai University (formally known as Kinki University), Higashiosaka, Japan
| | - Atsufumi Kawabata
- Laboratory of Pharmacology and Pathophysiology, Faculty of Pharmacy, Kindai University (formally known as Kinki University), Higashiosaka, Japan
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5
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Lv WL, Arnesano F, Carloni P, Natile G, Rossetti G. Effect of in vivo post-translational modifications of the HMGB1 protein upon binding to platinated DNA: a molecular simulation study. Nucleic Acids Res 2019; 46:11687-11697. [PMID: 30407547 PMCID: PMC6294504 DOI: 10.1093/nar/gky1082] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/01/2018] [Accepted: 10/19/2018] [Indexed: 12/26/2022] Open
Abstract
Cisplatin is one of the most widely used anticancer drugs. Its efficiency is unfortunately severely hampered by resistance. The High Mobility Group Box (HMGB) proteins may sensitize tumor cells to cisplatin by specifically binding to platinated DNA (PtDNA) lesions. In vivo, the HMGB/PtDNA binding is regulated by multisite post-translational modifications (PTMs). The impact of PTMs on the HMGB/PtDNA complex at atomistic level is here investigated by enhanced sampling molecular simulations. The PTMs turn out to affect the structure of the complex, the mobility of several regions (including the platinated site), and the nature of the protein/PtDNA non-covalent interactions. Overall, the multisite PTMs increase significantly the apparent synchrony of all the contacts between the protein and PtDNA. Consequently, the hydrophobic anchoring of the side chain of F37 between the two cross-linked guanines at the platinated site-a key element of the complexes formation - is more stable than in the complex without PTM. These differences can account for the experimentally measured greater affinity for PtDNA of the protein isoforms with PTMs. The collective behavior of multisite PTMs, as revealed here by the synchrony of contacts, may have a general significance for the modulation of intermolecular recognitions occurring in vivo.
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Affiliation(s)
- Wenping Lyu Lv
- Computational Biomedicine, Institute for Advanced Simulation IAS-5 and Institute of Neuroscience and Medicine INM-9, Forschungszentrum Jülich, 52425 Jülich, Germany.,Faculty of Mathematics, Computer Science and Natural Sciences, RWTH-Aachen University, 52056 Aachen, Germany.,Computation-Based Science and Technology Research Center, Cyprus Institute, 2121 Aglantzia, Nicosia, Cyprus
| | - Fabio Arnesano
- Department of Chemistry, University of Bari "A. Moro", via Edoardo Orabona 4, 70125 Bari, Italy
| | - Paolo Carloni
- Computational Biomedicine, Institute for Advanced Simulation IAS-5 and Institute of Neuroscience and Medicine INM-9, Forschungszentrum Jülich, 52425 Jülich, Germany
| | - Giovanni Natile
- Department of Chemistry, University of Bari "A. Moro", via Edoardo Orabona 4, 70125 Bari, Italy
| | - Giulia Rossetti
- Computational Biomedicine, Institute for Advanced Simulation IAS-5 and Institute of Neuroscience and Medicine INM-9, Forschungszentrum Jülich, 52425 Jülich, Germany.,Department of Hematology, Oncology, Hemostaseology, and Stem Cell Transplantation, Faculty of Medicine, RWTH Aachen University, 52062 Aachen, Germany.,Jülich Supercomputing Centre (JSC), Forschungszentrum Jülich, 52425 Jülich, Germany
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6
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Chen X, Xu Y, Xiong P, Tan Z, Gong F, Hou X, Zheng F. Effects of mimicked acetylated HMGB1 on macrophages and dendritic cells. Mol Med Rep 2018; 18:5527-5535. [PMID: 30365069 PMCID: PMC6236298 DOI: 10.3892/mmr.2018.9584] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2018] [Accepted: 07/25/2018] [Indexed: 11/05/2022] Open
Abstract
Extracellular high mobility group box 1 (HMGB1) serves a critical role in inflammatory diseases. HMGB1 is released into the extracellular environment mainly by passive release from necrotic cells or active secretion from monocytes/macrophages following stimulation. However, the translocation of actively secreted HMGB1 from the nucleus to the cytoplasm with post‑translational modifications such as acetylation is required; HMGB1 is then released into the extracellular space. Whether acetylation influences the extracellular function of HMGB1 remains unknown. In the present study, an optimized method of gene mutation by using well‑designed primers in particular, which were employed to identify the mutant gene. The substitution of six lysine residues for glutamines was conducted to mimic acetylated HMGB1 (HMGB1‑M) and observe the effects of HMGB1‑M on macrophages and dendritic cells (DCs). Tumor necrosis factor (TNF)‑α production in RAW 264.7 cells was assessed by ELISA. The phagocytic potential of RAW 264.7 cells, DC maturation and CXCR4 expression were analyzed by flow cytometry. The results of the present study revealed that HMGB1‑M increased cytoplasmic translocation. Compared with HMGB1, HMGB1‑M increased TNF‑α production within RAW 264.7 cells and decreased the mean fluorescence intensity (MFI) of integrin α X, and the percentage and MFI of major histocompatibility complex‑II on DCs. HMGB1‑M exhibited no significant effects on phagocytosis of macrophages and expression frequency of cluster of differentiation 80 and chemokine receptor type 4 on DCs. These results suggested that HMGB1‑M may partly promote inflammation and decrease DC maturation. Thus, the findings of the present study may provide insight into the complex role of HMGB1 in inflammatory diseases.
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Affiliation(s)
- Xiaohong Chen
- Division of Gastroenterology, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei 430022, P.R. China
| | - Yong Xu
- Department of Immunology, School of Basic Medicine, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei 430030, P.R. China
| | - Ping Xiong
- Department of Immunology, School of Basic Medicine, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei 430030, P.R. China
| | - Zheng Tan
- Department of Immunology, School of Basic Medicine, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei 430030, P.R. China
| | - Feili Gong
- Department of Immunology, School of Basic Medicine, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei 430030, P.R. China
| | - Xiaohua Hou
- Division of Gastroenterology, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei 430022, P.R. China
| | - Fang Zheng
- Department of Immunology, School of Basic Medicine, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei 430030, P.R. China
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7
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He SJ, Cheng J, Feng X, Yu Y, Tian L, Huang Q. The dual role and therapeutic potential of high-mobility group box 1 in cancer. Oncotarget 2017; 8:64534-64550. [PMID: 28969092 PMCID: PMC5610024 DOI: 10.18632/oncotarget.17885] [Citation(s) in RCA: 93] [Impact Index Per Article: 13.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2016] [Accepted: 04/24/2017] [Indexed: 12/31/2022] Open
Abstract
High-mobility group box 1 (HMGB1) is an abundant protein in most eukaryocytes. It can bind to several receptors such as advanced glycation end products (RAGE) and Toll-like receptors (TLRs), in direct or indirect way. The biological effects of HMGB1 depend on its expression and subcellular location. Inside the nucleus, HMGB1 is engaged in many DNA events such as DNA repair, transcription, telomere maintenance, and genome stability. While outside the nucleus, it possesses more complicated functions, including regulating cell proliferation, autophagy, inflammation and immunity. During tumor development, HMGB1 has been characterized as both a pro- and anti-tumoral protein by either promoting or suppressing tumor growth, proliferation, angiogenesis, invasion and metastasis. However, the current knowledge concerning the positive and negative effects of HMGB1 on tumor development is not explicit. Here, we evaluate the role of HMGB1 in tumor development and attempt to reconcile the dual effects of HMGB1 in carcinogenesis. Furthermore, we would like to present current strategies targeting against HMGB1, its receptor or release, which have shown potentially therapeutic value in cancer intervention.
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Affiliation(s)
- Si-Jia He
- Cancer Center, Shanghai General Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China.,Shanghai Key Laboratory of Pancreatic Diseases, Shanghai General Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Jin Cheng
- Cancer Center, Shanghai General Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China.,Shanghai Key Laboratory of Pancreatic Diseases, Shanghai General Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Xiao Feng
- Cancer Center, Shanghai General Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China.,Shanghai Key Laboratory of Pancreatic Diseases, Shanghai General Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Yang Yu
- Oncology Department, Henan Provincial People's Hospital, Zhengzhou, China
| | - Ling Tian
- Cancer Center, Shanghai General Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China.,Shanghai Key Laboratory of Pancreatic Diseases, Shanghai General Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China.,Institute of Translational Medicine, Shanghai General Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Qian Huang
- Cancer Center, Shanghai General Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China.,Shanghai Key Laboratory of Pancreatic Diseases, Shanghai General Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China
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8
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A. Richard S, Min W, Su Z, Xu HX. Epochal neuroinflammatory role of high mobility group box 1 in central nervous system diseases. AIMS MOLECULAR SCIENCE 2017. [DOI: 10.3934/molsci.2017.2.185] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
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9
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Ugrinova I, Pasheva E. HMGB1 Protein: A Therapeutic Target Inside and Outside the Cell. ADVANCES IN PROTEIN CHEMISTRY AND STRUCTURAL BIOLOGY 2016; 107:37-76. [PMID: 28215228 DOI: 10.1016/bs.apcsb.2016.10.001] [Citation(s) in RCA: 41] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
High-mobility group box 1 protein (HMGB1) is a nonhistone chromosomal protein discovered more than 30 years ago. It is an abundant nuclear protein that has a dual function-in the nucleus, it binds DNA and participates in practically all DNA-dependent processes serving as an architectural factor. Outside the cell, HMGB1 plays a different role-it acts as an alarmine that activates a large number of HMGB1-"competent" cells and mediates a broad range of physiological and pathological responses. This universality makes it an attractive target for innovative therapeutic strategies in the treatment of various diseases. Here we present an overview of the major nuclear and extracellular properties of HMGB1 and describe its interaction with different molecular partners as specific receptors or inhibitors, which are important for its role as a target in multiple diseases. We highlight its pivotal role as a target for cancer treatment at two aspects: first in terms of its substantial impact on the repair capacity of cancer cells, thus affecting the effectiveness of chemotherapy with the antitumor drug cis-platinum and, second, the possibility to be targeted by microRNAs influencing different pathways of human diseases, thus making it a promising candidate for a new strategy for therapeutic interventions against various pathological conditions but mainly cancer.
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Affiliation(s)
- I Ugrinova
- "Roumen Tsanev" Institute of Molecular Biology, Bulgarian Academy of Sciences, Sofia, Bulgaria.
| | - E Pasheva
- "Roumen Tsanev" Institute of Molecular Biology, Bulgarian Academy of Sciences, Sofia, Bulgaria
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10
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Abstract
Eukaryotic genomes are packaged in chromatin. The higher-order organization of nucleosome core particles is controlled by the association of the intervening linker DNA with either the linker histone H1 or high mobility group box (HMGB) proteins. While H1 is thought to stabilize the nucleosome by preventing DNA unwrapping, the DNA bending imposed by HMGB may propagate to the nucleosome to destabilize chromatin. For metazoan H1, chromatin compaction requires its lysine-rich C-terminal domain, a domain that is buried between globular domains in the previously characterized yeast Saccharomyces cerevisiae linker histone Hho1p. Here, we discuss the functions of S. cerevisiae HMO1, an HMGB family protein unique in containing a terminal lysine-rich domain and in stabilizing genomic DNA. On ribosomal DNA (rDNA) and genes encoding ribosomal proteins, HMO1 appears to exert its role primarily by stabilizing nucleosome-free regions or "fragile" nucleosomes. During replication, HMO1 likewise appears to ensure low nucleosome density at DNA junctions associated with the DNA damage response or the need for topoisomerases to resolve catenanes. Notably, HMO1 shares with the mammalian linker histone H1 the ability to stabilize chromatin, as evidenced by the absence of HMO1 creating a more dynamic chromatin environment that is more sensitive to nuclease digestion and in which chromatin-remodeling events associated with DNA double-strand break repair occur faster; such chromatin stabilization requires the lysine-rich extension of HMO1. Thus, HMO1 appears to have evolved a unique linker histone-like function involving the ability to stabilize both conventional nucleosome arrays as well as DNA regions characterized by low nucleosome density or the presence of noncanonical nucleosomes.
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11
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Yusein-Myashkova S, Ugrinova I, Pasheva E. Non-histone protein HMGB1 inhibits the repair of damaged DNA by cisplatin in NIH-3T3 murine fibroblasts. BMB Rep 2016; 49:99-104. [PMID: 24325815 PMCID: PMC4915123 DOI: 10.5483/bmbrep.2016.49.2.238] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2013] [Indexed: 11/20/2022] Open
Abstract
The nuclear non-histone protein high mobility group box (HMGB) 1 is known to having an inhibitory effect on the repair of DNA damaged by the antitumor drug cisplatin in vitro. To investigate the role of HMGB1 in living cells, we studied the DNA repair of cisplatin damages in mouse fibroblast cell line, NIH-3T3. We evaluated the effect of the post-synthetic acetylation and C-terminal domain of the protein by overexpression of the parental and mutant GFP fused forms of HMGB1. The results revealed that HMGB1 had also an inhibitory effect on the repair of cisplatin damaged DNA in vivo. The silencing of HMGB1 in NIH-3T3 cells increased the cellular DNA repair potential. The increased levels of repair synthesis could be "rescued" and returned to less than normal levels if the knockdown cells were transfected with plasmids encoding HMGB1 and HMGB1 K2A. In this case, the truncated form of HMGB1 also exhibited a slight inhibitory effect. [BMB Reports 2016; 49(2): 99-104].
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Affiliation(s)
- Shazie Yusein-Myashkova
- Institute of Molecular Biology, Roumen Tsanev, Bulgarian Academy of Sciences, Sofia 1113, Bulgaria
| | - Iva Ugrinova
- Institute of Molecular Biology, Roumen Tsanev, Bulgarian Academy of Sciences, Sofia 1113, Bulgaria
| | - Evdokia Pasheva
- Institute of Molecular Biology, Roumen Tsanev, Bulgarian Academy of Sciences, Sofia 1113, Bulgaria
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12
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A quantitative investigation of linker histone interactions with nucleosomes and chromatin. Sci Rep 2016; 6:19122. [PMID: 26750377 PMCID: PMC4707517 DOI: 10.1038/srep19122] [Citation(s) in RCA: 48] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2015] [Accepted: 12/07/2015] [Indexed: 12/20/2022] Open
Abstract
Linker histones such as H1 are abundant basic proteins that bind tightly to nucleosomes, thereby acting as key organizers of chromatin structure. The molecular details of linker histone interactions with the nucleosome, and in particular the contributions of linker DNA and of the basic C-terminal tail of H1, are controversial. Here we combine rigorous solution-state binding assays with native gel electrophoresis and Atomic Force Microscopy, to quantify the interaction of H1 with chromatin. We find that H1 binds nucleosomes and nucleosomal arrays with very tight affinity by recognizing a specific DNA geometry minimally consisting of a solitary nucleosome with a single ~18 base pair DNA linker arm. The association of H1 alters the conformation of trinucleosomes so that only one H1 can bind to the two available linker DNA regions. Neither incorporation of the histone variant H2A.Z, nor the presence of neighboring nucleosomes affects H1 affinity. Our data provide a comprehensive thermodynamic framework for this ubiquitous chromatin architectural protein.
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13
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Thapar R. Structure-specific nucleic acid recognition by L-motifs and their diverse roles in expression and regulation of the genome. BIOCHIMICA ET BIOPHYSICA ACTA-GENE REGULATORY MECHANISMS 2015; 1849:677-87. [PMID: 25748361 DOI: 10.1016/j.bbagrm.2015.02.006] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/18/2014] [Revised: 02/05/2015] [Accepted: 02/24/2015] [Indexed: 01/08/2023]
Abstract
The high-mobility group (HMG) domain containing proteins regulate transcription, DNA replication and recombination. They adopt L-shaped folds and are structure-specific DNA binding motifs. Here, I define the L-motif super-family that consists of DNA-binding HMG-box proteins and the L-motif of the histone mRNA binding domain of stem-loop binding protein (SLBP). The SLBP L-motif and HMG-box domains adopt similar L-shaped folds with three α-helices and two or three small hydrophobic cores that stabilize the overall fold, but have very different and distinct modes of nucleic acid recognition. A comparison of the structure, dynamics, protein-protein and nucleic acid interactions, and regulation by PTMs of the SLBP and the HMG-box L-motifs reveals the versatile and diverse modes by which L-motifs utilize their surfaces for structure-specific recognition of nucleic acids to regulate gene expression.
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Affiliation(s)
- Roopa Thapar
- BioSciences at Rice-Biochemistry and Cell Biology, Rice University, Houston, TX 77251-1892, USA.
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Curcumin attenuated acute Propionibacterium acnes -induced liver injury through inhibition of HMGB1 expression in mice. Int Immunopharmacol 2015; 24:159-165. [DOI: 10.1016/j.intimp.2014.12.005] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/23/2014] [Revised: 11/19/2014] [Accepted: 12/03/2014] [Indexed: 12/27/2022]
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15
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Wu F, Zhao ZH, Ding ST, Wu HH, Lu JJ. High mobility group box 1 protein is methylated and transported to cytoplasm in clear cell renal cell carcinoma. Asian Pac J Cancer Prev 2015; 14:5789-95. [PMID: 24289579 DOI: 10.7314/apjcp.2013.14.10.5789] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND The high mobility group box 1 (HMGB1) protein is a widespread nuclear protein present in most cell types. It typically locates in the nucleus and functions as a nuclear cofactor in transcription regulation. However, HMGB1 can also localize in the cytoplasm and be released into extracellular matrix, where it plays critical roles in carcinogenesis and inflammation. However, it remains elusive whether HMGB1 is relocated to cytoplasm in clear cell renal cell carcinoma (ccRCC). METHODS Nuclear and cytoplasmic proteins were extracted by different protocols from 20 ccRCC samples and corresponding adjacent renal tissues. Western blotting and immunohistochemistry were used to identify the expression of HMGB1 in ccRCC. To elucidate the potential mechanism of HMGB1 cytoplasmic translocation, HMGB1 proteins were enriched by immunoprecipitation and analyzed by mass spectrometry (MS). RESULTS The HMGB1 protein was overexpressed and partially localized in cytoplasm in ccRCC samples (12/20, 60%, p<0.05). Immunohistochemistry results indicated that ccRCC of high nuclear grade possess more HMGB1 relocation than those with low grade (p<0.05). Methylation of HMGB1 at lysine 112 in ccRCC was detected by MS. Bioinformatics analysis showed that post-translational modification might affect the binding ability to DNA and mediate its translocation. CONCLUSION Relocation of HMGB1 to cytoplasm was confirmed in ccRCC. Methylation of HMGB1 at lysine 112 might the redistribution of this cofactor protein.
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Affiliation(s)
- Fei Wu
- Department of Urology, Provincial Hospital Affiliated to Shandong University, Jinan, China E-mail :
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Kang R, Chen R, Zhang Q, Hou W, Wu S, Cao L, Huang J, Yu Y, Fan XG, Yan Z, Sun X, Wang H, Wang Q, Tsung A, Billiar TR, Zeh HJ, Lotze MT, Tang D. HMGB1 in health and disease. Mol Aspects Med 2014; 40:1-116. [PMID: 25010388 PMCID: PMC4254084 DOI: 10.1016/j.mam.2014.05.001] [Citation(s) in RCA: 683] [Impact Index Per Article: 68.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2014] [Accepted: 05/05/2014] [Indexed: 12/22/2022]
Abstract
Complex genetic and physiological variations as well as environmental factors that drive emergence of chromosomal instability, development of unscheduled cell death, skewed differentiation, and altered metabolism are central to the pathogenesis of human diseases and disorders. Understanding the molecular bases for these processes is important for the development of new diagnostic biomarkers, and for identifying new therapeutic targets. In 1973, a group of non-histone nuclear proteins with high electrophoretic mobility was discovered and termed high-mobility group (HMG) proteins. The HMG proteins include three superfamilies termed HMGB, HMGN, and HMGA. High-mobility group box 1 (HMGB1), the most abundant and well-studied HMG protein, senses and coordinates the cellular stress response and plays a critical role not only inside of the cell as a DNA chaperone, chromosome guardian, autophagy sustainer, and protector from apoptotic cell death, but also outside the cell as the prototypic damage associated molecular pattern molecule (DAMP). This DAMP, in conjunction with other factors, thus has cytokine, chemokine, and growth factor activity, orchestrating the inflammatory and immune response. All of these characteristics make HMGB1 a critical molecular target in multiple human diseases including infectious diseases, ischemia, immune disorders, neurodegenerative diseases, metabolic disorders, and cancer. Indeed, a number of emergent strategies have been used to inhibit HMGB1 expression, release, and activity in vitro and in vivo. These include antibodies, peptide inhibitors, RNAi, anti-coagulants, endogenous hormones, various chemical compounds, HMGB1-receptor and signaling pathway inhibition, artificial DNAs, physical strategies including vagus nerve stimulation and other surgical approaches. Future work further investigating the details of HMGB1 localization, structure, post-translational modification, and identification of additional partners will undoubtedly uncover additional secrets regarding HMGB1's multiple functions.
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Affiliation(s)
- Rui Kang
- Department of Surgery, University of Pittsburgh, Pittsburgh, Pennsylvania 15213, USA.
| | - Ruochan Chen
- Department of Surgery, University of Pittsburgh, Pittsburgh, Pennsylvania 15213, USA
| | - Qiuhong Zhang
- Department of Surgery, University of Pittsburgh, Pittsburgh, Pennsylvania 15213, USA
| | - Wen Hou
- Department of Surgery, University of Pittsburgh, Pittsburgh, Pennsylvania 15213, USA
| | - Sha Wu
- Department of Surgery, University of Pittsburgh, Pittsburgh, Pennsylvania 15213, USA
| | - Lizhi Cao
- Department of Pediatrics, Xiangya Hospital, Central South University, Changsha, Hunan 410008, China
| | - Jin Huang
- Department of Oncology, Xiangya Hospital, Central South University, Changsha, Hunan 410008, China
| | - Yan Yu
- Department of Pediatrics, Xiangya Hospital, Central South University, Changsha, Hunan 410008, China
| | - Xue-Gong Fan
- Department of Infectious Diseases, Xiangya Hospital, Central South University, Changsha, Hunan 410008, China
| | - Zhengwen Yan
- Department of Surgery, University of Pittsburgh, Pittsburgh, Pennsylvania 15213, USA; Department of Neurology, Sun Yat-Sen Memorial Hospital, Sun Yat-Sen University, Guangzhou, Guangdong 510120, China
| | - Xiaofang Sun
- Key Laboratory for Major Obstetric Diseases of Guangdong Province, Key Laboratory of Reproduction and Genetics of Guangdong Higher Education Institutes, Experimental Department of Institute of Gynecology and Obstetrics, The Third Affiliated Hospital of Guangzhou Medical University, Guangzhou, Guangdong 510510, China
| | - Haichao Wang
- Laboratory of Emergency Medicine, The Feinstein Institute for Medical Research, Manhasset, NY 11030, USA
| | - Qingde Wang
- Department of Surgery, University of Pittsburgh, Pittsburgh, Pennsylvania 15213, USA
| | - Allan Tsung
- Department of Surgery, University of Pittsburgh, Pittsburgh, Pennsylvania 15213, USA
| | - Timothy R Billiar
- Department of Surgery, University of Pittsburgh, Pittsburgh, Pennsylvania 15213, USA
| | - Herbert J Zeh
- Department of Surgery, University of Pittsburgh, Pittsburgh, Pennsylvania 15213, USA
| | - Michael T Lotze
- Department of Surgery, University of Pittsburgh, Pittsburgh, Pennsylvania 15213, USA
| | - Daolin Tang
- Department of Surgery, University of Pittsburgh, Pittsburgh, Pennsylvania 15213, USA.
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Zhang F, Huang G, Hu B, Qian GS, Song Y. Recombinant HMGB1 A box protein inhibits Th17 responses in mice with neutrophilic asthma by suppressing dendritic cell-mediated Th17 polarization. Int Immunopharmacol 2014; 24:110-8. [PMID: 25479722 DOI: 10.1016/j.intimp.2014.11.005] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2014] [Accepted: 11/06/2014] [Indexed: 11/28/2022]
Abstract
High mobility group box chromosomal protein 1 (HMGB1) is a critical pro-inflammatory cytokine involved in diverse inflammatory diseases and has important immunomodulatory effects on allergic asthma. Our recent studies demonstrate that HMGB1) ^ReloadFigure=Yes1 expression increases in the lung tissue and associates with interleukin-17(+) (IL-17) helper T cell (Th17) responses in a murine model of neutrophilic asthma. In this study, to examine the immunomodulatory mechanisms of HMGB1, we evaluated the effects of recombinant HMGB1 A box (an antagonist of HMGB1) administration on allergic airway inflammation and lung antigen-presenting cell (APC) function in a murine model of neutrophilic asthma. In OVA-challenged mice, rHMGB1 A box attenuated HMGB1 expression, airway neutrophilic inflammation and hyper-responsiveness. In addition, the administration of rHMGB1 A box decreased the number of Th17 cells and IL-23(+) CD11c(+) APCs in lung cells. In vivo, rHMGB1 A box revealed an inhibitory effect of rHMGB1-activated dendritic cells (DCs) to produce IL-23 and induce a Th17 response. Finally, we showed that adoptive transfer of rHMGB1-activated DCs was sufficient to restore the characteristics of neutrophilic asthma in a DCs-driven model of asthma, whereas the transfer of rHMGB1 A box plus rHMGB1-activated DCs significantly reduced these inflammation phenotypes. These data demonstrate that rHMGB1 A box may have therapeutic effects on controlling Th17 polarization and airway inflammation in neutrophilic asthma by blocking the HMGB1 pathway on DCs.
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Affiliation(s)
- Fang Zhang
- Department of Pulmonary Medicine, Jinling Hospital, Nanjing University School of Medicine, Nanjing 210002, China.
| | - Gang Huang
- Department of Medical Genetics, The Third Military Medical University, Chongqing 400038, China
| | - Bo Hu
- Department of Pulmonary Medicine, Jinling Hospital, Nanjing University School of Medicine, Nanjing 210002, China
| | - Gui-sheng Qian
- Department of Pulmonary Medicine, Xinqiao Hospital, The Third Military Medical University, Chongqing 400038, China
| | - Yong Song
- Department of Pulmonary Medicine, Jinling Hospital, Nanjing University School of Medicine, Nanjing 210002, China.
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A nuclear factor of high mobility group box protein in Toxoplasma gondii. PLoS One 2014; 9:e111993. [PMID: 25369210 PMCID: PMC4219823 DOI: 10.1371/journal.pone.0111993] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2014] [Accepted: 10/08/2014] [Indexed: 01/28/2023] Open
Abstract
High mobility group box 1 (HMGB1) is a nuclear factor that usually binds DNA and modulates gene expression in multicellular organisms. Three HMGB1 orthologs were predicted in the genome of Toxoplasma gondii, an obligate intracellular protozoan pathogen, termed TgHMGB1a, b and c. Phylogenetic and bioinformatic analyses indicated that these proteins all contain a single HMG box and which shared in three genotypes. We cloned TgHMGB1a, a 33.9 kDa protein that can stimulates macrophages to release TNF-α, and, we demonstrated that the TgHMGB1a binds distorted DNA structures such as cruciform DNA in electrophoretic mobility shift assays (EMSA). Immunofluorescence assay indicated TgHMGB1a concentrated in the nucleus of intracellular tachyzoites but translocated into the cytoplasm while the parasites release to extracellular. There were no significant phenotypic changes when the TgHMGB1a B box was deleted, while transgenic parasites that overexpressed TgHMGB1a showed slower intracellular growth and caused delayed death in mouse, further quantitative RT-PCR analyses showed that the expression levels of many important genes, including virulence factors, increased when TgHMGB1a was overexpressed, but no significant changes were observed in TgHMGB1a B box-deficient parasites. Our findings demonstrated that TgHMGB1a is indeed a nuclear protein that maintains HMG box architectural functions and is a potential proinflammatory factor during the T.gondii infection. Further studies that clarify the functions of TgHMGB1s will increase our knowledge of transcriptional regulation and parasite virulence, and might provide new insight into host-parasite interactions for T. gondii infection.
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Nguyen TH, Rossetti G, Arnesano F, Ippoliti E, Natile G, Carloni P. Molecular Recognition of Platinated DNA from Chromosomal HMGB1. J Chem Theory Comput 2014; 10:3578-84. [PMID: 26588321 DOI: 10.1021/ct500402e] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/14/2023]
Abstract
Cisplatin cures testicular and ovarian cancers with unprecedented potency. It induces its beneficial activity by covalently binding to DNA. Repair enzymes, which remove the platinated lesions from DNA, cause drug resistance. Chromosomal High Mobility Group Box proteins (HMGB) may interfere with this process by binding to platinated DNA. Using 8 μs multiple-walker well-tempered metadynamics simulations, here, we investigated the structural and the energetic determinants of one of the HMGB proteins (HMGB1A) in complex with the platinated oligonucleotide [Pt(NH3)2](2+)-d(CCUCTCTG*G*ACCTTCC)-d(GGAGAGACCTGGAAGG) (*G are platinated guanines), for which experimental structural information is available. The calculated affinity is in good agreement with experiment. The process is predicted to be enthalpy-driven, as found for other protein/DNA complexes. The Lys7 residue, whose side-chain was not resolved in the X-ray structure, is found to interact with the C4 5'-phosphate and this interaction emerges as a key facet for the molecular recognition process. In addition, our calculations provide a molecular basis for the experimentally measured decreased affinity of HMGB1A for platinated DNA, as a consequence of Cys22-Cys44 S-S bridge formation (such an oxidation cannot take place in some members of this protein family present in the testis, where the drug is particularly effective). This decrease is likely to be caused by a small yet significant rearrangement of helices H1 and H2 with consequent alteration of the Phe37 juxtaposition.
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Affiliation(s)
- Trung Hai Nguyen
- Computational Biophysics, German Research School for Simulation Sciences (joint venture of RWTH Aachen University and Forschungszentrum Jülich, Germany) , D-52425 Jülich, Germany.,Institute for Advanced Simulation IAS-5, Computational Biomedicine, Forschungszentrum Jülich , D-52425 Jülich, Germany.,Computational Biomedicine section (INM-9), Institute for Neuroscience and Medicine (INM) , 52425 Jülich, Germany
| | - Giulia Rossetti
- Computational Biophysics, German Research School for Simulation Sciences (joint venture of RWTH Aachen University and Forschungszentrum Jülich, Germany) , D-52425 Jülich, Germany.,Institute for Advanced Simulation IAS-5, Computational Biomedicine, Forschungszentrum Jülich , D-52425 Jülich, Germany.,Computational Biomedicine section (INM-9), Institute for Neuroscience and Medicine (INM) , 52425 Jülich, Germany.,Institute for Research in Biomedicine (IRB Barcelona), Baldiri Reixac 10, Barcelona 08028, Spain.,Joint IRB-BSC Program in Computational Biology, Barcelona, Spain.,Jülich Supercomputing Centre (JSC), Forschungszentrum Jülich, D-52425 Jülich, Germany
| | - Fabio Arnesano
- Department of Chemistry, University of Bari "A. Moro" , via Edoardo Orabona 4, I-70125 Bari, Italy
| | - Emiliano Ippoliti
- Computational Biophysics, German Research School for Simulation Sciences (joint venture of RWTH Aachen University and Forschungszentrum Jülich, Germany) , D-52425 Jülich, Germany.,Institute for Advanced Simulation IAS-5, Computational Biomedicine, Forschungszentrum Jülich , D-52425 Jülich, Germany.,Computational Biomedicine section (INM-9), Institute for Neuroscience and Medicine (INM) , 52425 Jülich, Germany
| | - Giovanni Natile
- Department of Chemistry, University of Bari "A. Moro" , via Edoardo Orabona 4, I-70125 Bari, Italy
| | - Paolo Carloni
- Computational Biophysics, German Research School for Simulation Sciences (joint venture of RWTH Aachen University and Forschungszentrum Jülich, Germany) , D-52425 Jülich, Germany.,Institute for Advanced Simulation IAS-5, Computational Biomedicine, Forschungszentrum Jülich , D-52425 Jülich, Germany.,Computational Biomedicine section (INM-9), Institute for Neuroscience and Medicine (INM) , 52425 Jülich, Germany
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Sukackaite R, Jensen MR, Mas PJ, Blackledge M, Buonomo SB, Hart DJ. Structural and biophysical characterization of murine rif1 C terminus reveals high specificity for DNA cruciform structures. J Biol Chem 2014; 289:13903-11. [PMID: 24634216 DOI: 10.1074/jbc.m114.557843] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
Mammalian Rif1 is a key regulator of DNA replication timing, double-stranded DNA break repair, and replication fork restart. Dissecting the molecular functions of Rif1 is essential to understand how it regulates such diverse processes. However, Rif1 is a large protein that lacks well defined functional domains and is predicted to be largely intrinsically disordered; these features have hampered recombinant expression of Rif1 and subsequent functional characterization. Here we applied ESPRIT (expression of soluble proteins by random incremental truncation), an in vitro evolution-like approach, to identify high yielding soluble fragments encompassing conserved regions I and II (CRI and CRII) at the C-terminal region of murine Rif1. NMR analysis showed CRI to be intrinsically disordered, whereas CRII is partially folded. CRII binds cruciform DNA with high selectivity and micromolar affinity and thus represents a functional DNA binding domain. Mutational analysis revealed an α-helical region of CRII to be important for cruciform DNA binding and identified critical residues. Thus, we present the first structural study of the mammalian Rif1, identifying a domain that directly links its function to DNA binding. The high specificity of Rif1 for cruciform structures is significant given the role of this key protein in regulating origin firing and DNA repair.
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Affiliation(s)
- Rasa Sukackaite
- From the European Molecular Biology Laboratory (EMBL), Grenoble Outstation, 6 rue Jules Horowitz, 38042 France, the Unit for Virus Host-Cell Interactions, University of Grenoble Alpes-EMBL-CNRS, 6 rue Jules Horowitz, 38042 France, the European Molecular Biology Laboratory, Monterotondo Outstation, Adriano Buzzati-Traverso Campus, Via Ramarini 32, 00015 Monterotondo, Italy
| | - Malene Ringkjøbing Jensen
- the University of Grenoble Alpes, Institut de Biologie Structurale (IBS), 6 rue Jules Horowitz, F-38027 Grenoble, France, CEA, DSV, IBS, 6 rue Jules Horowitz, F-38027 Grenoble, France, CNRS, IBS, 6 rue Jules Horowitz, F-38027 Grenoble, France, and
| | - Philippe J Mas
- From the European Molecular Biology Laboratory (EMBL), Grenoble Outstation, 6 rue Jules Horowitz, 38042 France, the Unit for Virus Host-Cell Interactions, University of Grenoble Alpes-EMBL-CNRS, 6 rue Jules Horowitz, 38042 France
| | - Martin Blackledge
- the University of Grenoble Alpes, Institut de Biologie Structurale (IBS), 6 rue Jules Horowitz, F-38027 Grenoble, France, CEA, DSV, IBS, 6 rue Jules Horowitz, F-38027 Grenoble, France, CNRS, IBS, 6 rue Jules Horowitz, F-38027 Grenoble, France, and
| | - Sara B Buonomo
- the European Molecular Biology Laboratory, Monterotondo Outstation, Adriano Buzzati-Traverso Campus, Via Ramarini 32, 00015 Monterotondo, Italy
| | - Darren J Hart
- From the European Molecular Biology Laboratory (EMBL), Grenoble Outstation, 6 rue Jules Horowitz, 38042 France, the Unit for Virus Host-Cell Interactions, University of Grenoble Alpes-EMBL-CNRS, 6 rue Jules Horowitz, 38042 France,
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Grüning NM, Du D, Keller MA, Luisi BF, Ralser M. Inhibition of triosephosphate isomerase by phosphoenolpyruvate in the feedback-regulation of glycolysis. Open Biol 2014; 4:130232. [PMID: 24598263 PMCID: PMC3971408 DOI: 10.1098/rsob.130232] [Citation(s) in RCA: 75] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023] Open
Abstract
The inhibition of triosephosphate isomerase (TPI) in glycolysis by the pyruvate kinase (PK) substrate phosphoenolpyruvate (PEP) results in a newly discovered feedback loop that counters oxidative stress in cancer and actively respiring cells. The mechanism underlying this inhibition is illuminated by the co-crystal structure of TPI with bound PEP at 1.6 Å resolution, and by mutational studies guided by the crystallographic results. PEP is bound to the catalytic pocket of TPI and occludes substrate, which accounts for the observation that PEP competitively inhibits the interconversion of glyceraldehyde-3-phosphate and dihydroxyacetone phosphate. Replacing an isoleucine residue located in the catalytic pocket of TPI with valine or threonine altered binding of substrates and PEP, reducing TPI activity in vitro and in vivo. Confirming a TPI-mediated activation of the pentose phosphate pathway (PPP), transgenic yeast cells expressing these TPI mutations accumulate greater levels of PPP intermediates and have altered stress resistance, mimicking the activation of the PK-TPI feedback loop. These results support a model in which glycolytic regulation requires direct catalytic inhibition of TPI by the pyruvate kinase substrate PEP, mediating a protective metabolic self-reconfiguration of central metabolism under conditions of oxidative stress.
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Affiliation(s)
- Nana-Maria Grüning
- Department of Biochemistry, University of Cambridge, 80 Tennis Court Road, Cambridge CB2 1GA, UK
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Funayama A, Shishido T, Netsu S, Narumi T, Kadowaki S, Takahashi H, Miyamoto T, Watanabe T, Woo CH, Abe JI, Kuwahara K, Nakao K, Takeishi Y, Kubota I. Cardiac nuclear high mobility group box 1 prevents the development of cardiac hypertrophy and heart failure. Cardiovasc Res 2013; 99:657-64. [PMID: 23708738 PMCID: PMC3746952 DOI: 10.1093/cvr/cvt128] [Citation(s) in RCA: 61] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/14/2023] Open
Abstract
Aims High mobility group box 1 (HMGB1) is an abundant and ubiquitous nuclear DNA-binding protein that has multiple functions dependent on its cellular location. HMGB1 binds to DNA, facilitating numerous nuclear functions including maintenance of genome stability, transcription, and repair. However, little is known about the effects of nuclear HMGB1 on cardiac hypertrophy and heart failure. The aim of this study was to examine whether nuclear HMGB1 plays a role in the development of cardiac hypertrophy induced by pressure overload. Methods and results Analysis of human biopsy samples by immunohistochemistry showed decreased nuclear HMGB1 expression in failing hearts compared with normal hearts. Nuclear HMGB1 decreased in response to both endothelin-1 (ET-1) and angiotensin II (Ang II) stimulation in neonatal rat cardiomyocytes, where nuclear HMGB1 was acetylated and translocated to the cytoplasm. Overexpression of nuclear HMGB1 attenuated ET-1 induced cardiomyocyte hypertrophy. Thoracic transverse aortic constriction (TAC) was performed in transgenic mice with cardiac-specific overexpression of HMGB1 (HMGB1-Tg) and wild-type (WT) mice. Cardiac hypertrophy after TAC was attenuated in HMGB1-Tg mice and the survival rate after TAC was higher in HMGB1-Tg mice than in WT mice. Induction of foetal cardiac genes was decreased in HMGB1-Tg mice compared with WT mice. Nuclear HMGB1 expression was preserved in HMGB1-Tg mice compared with WT mice and significantly attenuated DNA damage after TAC was attenuated in HMGB1-TG mice. Conclusion These results suggest that the maintenance of stable nuclear HMGB1 levels prevents hypertrophy and heart failure by inhibiting DNA damage.
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Affiliation(s)
- Akira Funayama
- Department of Cardiology, Pulmonology, and Nephrology, Yamagata University School of Medicine, Japan
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Wang LW, Wang LK, Chen H, Fan C, Li X, He CM, Gong ZJ. Ethyl pyruvate protects against experimental acute-on-chronic liver failure in rats. World J Gastroenterol 2012; 18:5709-18. [PMID: 23155311 PMCID: PMC3484339 DOI: 10.3748/wjg.v18.i40.5709] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/01/2012] [Revised: 05/21/2012] [Accepted: 07/28/2012] [Indexed: 02/06/2023] Open
Abstract
AIM: To investigate the protective effects of ethyl pyruvate (EP) on acute-on-chronic liver failure (ACLF) in rats.
METHODS: An ACLF model was established in rats, and animals were randomly divided into normal, model and EP treatment groups. The rats in EP treatment group received EP (40 mg/kg) at 3 h, 6 h, 12 h and 24 h after induction of ACLF. Serum endotoxin, high mobility group box-1 (HMGB1), alanine transaminase (ALT), tumor necrosis factor-α (TNF-α), interferon-α (IFN-γ), interleukin (IL)-10 and IL-18 levels, changes of liver histology and HMGB1 expressions in liver tissues were detected at 48 h after induction of ACLF. The effects of EP on the survival of ACLF rats were also observed.
RESULTS: Serum levels of endotoxin (0.394 ± 0.066 EU/mL vs 0.086 ± 0.017 EU/mL, P < 0.001), HMGB1 (35.42 ± 10.86 μg/L vs 2.14 ± 0.27 μg/L, P < 0.001), ALT (8415.87 ± 3567.54 IU/L vs 38.64 ± 8.82 IU/L, P < 0.001), TNF-α (190.77 ± 12.34 ng/L vs 124.40 ± 4.12 ng/L, P < 0.001), IFN-γ (715.38 ± 86.03 ng/L vs 398.66 ± 32.91 ng/L, P < 0.001), IL-10 (6.85 ± 0.64 ng/L vs 3.49 ± 0.24 ng/L, P < 0.001) and IL-18 (85.19 ± 3.49 ng/L vs 55.38 ± 1.25 ng/L, P < 0.001) were significantly increased, and liver tissues presented severe pathological injury in the model group compared with the normal group. However, EP administration significantly improved hepatic histopathology and reduced the serum levels of endotoxin (0.155 ± 0.045 EU/mL vs 0.394 ± 0.066 EU/mL, P < 0.001) and inflammatory cytokines (11.13 ± 2.58 μg/L vs 35.42 ± 10.86 μg/L for HMGB1, 3512.86 ± 972.67 IU/L vs 8415.87 ± 3567.54 IU/L for ALT, 128.55 ± 5.76 ng/L vs 190.77 ± 12.34 ng/L for TNF-α, 438.16 ± 38.10 ng/L vs 715.38 ± 86.03 ng/L for IFN-γ, 3.55 ± 0.36 ng/L vs 6.85 ± 0.64 ng/L for IL-10, and 60.35 ± 1.63 ng/L vs 85.19 ± 3.49 ng/L for IL-18, respectively, P < 0.001), and the levels of HMGB1 in liver tissues regardless of treatment time after induction of ACLF. EP treatment at the four time points prolonged the median survival time of ACLF rats (60 h) to 162 h, 120 h, 102 h and 78 h, respectively (χ2 = 41.17, P < 0.0001).
CONCLUSION: EP administration can protect against ACLF in rats, and is a potential and novel therapeutic agent for severe liver injury.
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Lysine acetylation: elucidating the components of an emerging global signaling pathway in trypanosomes. J Biomed Biotechnol 2012; 2012:452934. [PMID: 23093844 PMCID: PMC3470893 DOI: 10.1155/2012/452934] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2012] [Revised: 07/20/2012] [Accepted: 07/30/2012] [Indexed: 12/31/2022] Open
Abstract
In the past ten years the number of acetylated proteins reported in literature grew exponentially. Several authors have proposed that acetylation might be a key component in most eukaryotic signaling pathways, as important as phosphorylation. The enzymes involved in this process are starting to emerge; acetyltransferases and deacetylases are found inside and outside the nuclear compartment and have different regulatory functions. In trypanosomatids several of these enzymes have been described and are postulated to be novel antiparasitic targets for the rational design of drugs. In this paper we overview the most important known acetylated proteins and the advances made in the identification of new acetylated proteins using high-resolution mass spectrometry. Also, we summarize what is known so far about the acetyltransferases and deacetylases in eukaryotes, focusing on trypanosomes and their potential use as chemotherapeutic targets.
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Brázda V, Laister RC, Jagelská EB, Arrowsmith C. Cruciform structures are a common DNA feature important for regulating biological processes. BMC Mol Biol 2011; 12:33. [PMID: 21816114 PMCID: PMC3176155 DOI: 10.1186/1471-2199-12-33] [Citation(s) in RCA: 177] [Impact Index Per Article: 13.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2011] [Accepted: 08/05/2011] [Indexed: 04/10/2023] Open
Abstract
DNA cruciforms play an important role in the regulation of natural processes involving DNA. These structures are formed by inverted repeats, and their stability is enhanced by DNA supercoiling. Cruciform structures are fundamentally important for a wide range of biological processes, including replication, regulation of gene expression, nucleosome structure and recombination. They also have been implicated in the evolution and development of diseases including cancer, Werner's syndrome and others. Cruciform structures are targets for many architectural and regulatory proteins, such as histones H1 and H5, topoisomerase IIβ, HMG proteins, HU, p53, the proto-oncogene protein DEK and others. A number of DNA-binding proteins, such as the HMGB-box family members, Rad54, BRCA1 protein, as well as PARP-1 polymerase, possess weak sequence specific DNA binding yet bind preferentially to cruciform structures. Some of these proteins are, in fact, capable of inducing the formation of cruciform structures upon DNA binding. In this article, we review the protein families that are involved in interacting with and regulating cruciform structures, including (a) the junction-resolving enzymes, (b) DNA repair proteins and transcription factors, (c) proteins involved in replication and (d) chromatin-associated proteins. The prevalence of cruciform structures and their roles in protein interactions, epigenetic regulation and the maintenance of cell homeostasis are also discussed.
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Affiliation(s)
- Václav Brázda
- Institute of Biophysics, Academy of Sciences of the Czech Republic, v,v,i,, Královopolská 135, Brno, 612 65, Czech Republic.
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Cribb P, Perozzi M, Villanova GV, Trochine A, Serra E. Characterization of TcHMGB, a high mobility group B family member protein from Trypanosoma cruzi. Int J Parasitol 2011; 41:1149-56. [PMID: 21854779 DOI: 10.1016/j.ijpara.2011.06.009] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2010] [Revised: 06/03/2011] [Accepted: 06/25/2011] [Indexed: 11/17/2022]
Abstract
High mobility group B (HMGB) proteins are highly abundant non-histone chromatin proteins that play important roles in the execution and control of many nuclear functions. Based on homology searches, we identified the coding sequence for the TcHMGB protein, an HMGB family member from Trypanosoma cruzi. TcHMGB has two HMG box domains, similar to mammalian HMGBs, but lacks the typical C-terminal acidic tail. Instead, it contains a 110 amino acid long N-terminal domain. The TcHMGB N-terminal domain is conserved between the TriTryp sequences (70-80% similarity) and seems to be characteristic of kinetoplastid HMGBs. Despite these differences, TcHMGB maintains HMG box architectural functions: we demonstrated that the trypanosomatid HMGB binds distorted DNA structures such as cruciform DNA in gel shift assays. TcHMGB is also able to bend linear DNA as determined by T4 ligase circularization assays, similar to other HMGB family members. Immunofluorescence and western blot assays showed that TcHMGB is a nuclear protein expressed in all life cycle stages. Protein levels, however, seem to vary throughout the life cycle, which may be related to previously described changes in heterochromatin distribution and transcription rates.
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Affiliation(s)
- Pamela Cribb
- Instituto de Biología Molecular y Celular de Rosario (IBR-CONICET), Facultad de Ciencias Bioquímicas y Farmacéuticas, Universidad Nacional de Rosario, Suipacha 531, Rosario CP2000, Argentina
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Elenkov I, Pelovsky P, Ugrinova I, Takahashi M, Pasheva E. The DNA binding and bending activities of truncated tail-less HMGB1 protein are differentially affected by Lys-2 and Lys-81 residues and their acetylation. Int J Biol Sci 2011; 7:691-9. [PMID: 21647302 PMCID: PMC3107488 DOI: 10.7150/ijbs.7.691] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2011] [Accepted: 05/24/2011] [Indexed: 11/24/2022] Open
Abstract
The role of lysines 2 and 81 as target sites for acetylation in full-length HMGB1 and truncated tail-less protein, respectively, has been studied by mutation analysis for the abilities of these proteins to bind and bend DNA. The DNA bending ability of truncated tail-less HMGB1 containing Lys-2 mutated to alanine does not differ from that of the wild-type protein, while the same mutation of Lys-81 reduced the bending capacity of the mutant protein. These data demonstrate that Lys-81 is critical for the DNA bending ability of truncated HMGB1. Such a conclusion is further confirmed by the experiments carried out with CBP-acetylated proteins: acetylation of Lys-2 in mutant protein K81/A81 alleviated DNA bending and induced DNA end-joining. On the contrary, the acetylation of Lys-81 in the mutant K2/A2 enhanced the bending potential of HMGB1∆C. Regarding the ability of HMGB1 to specifically bind bent DNA, the individual mutations of either K2 or K81 as well as the double mutation of both residues to alanine were found to completely abolish binding of truncated tail-less HMGB1 to cisplatin-modified DNA. We conclude that unlike the case with the bending ability of truncated HMGB1, where Lys-81 has a primary function, Lys-2 and Lys-81 are both critical for the protein's binding to cisplatin-modified DNA. The mutation K2/A2 in full-length HMGB1 and acidic tail removal induce the same conformational changes. Any further substitutions at the acetylable lysines in the truncated form of HMGB1 do not have an additional effect.
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Affiliation(s)
- Ivan Elenkov
- Institute of Moleculat Biology, Bulgarian Academy of Sciences, 1113 Sofia, Bulgaria
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Zhang Q, Wang Y. HMG modifications and nuclear function. BIOCHIMICA ET BIOPHYSICA ACTA-GENE REGULATORY MECHANISMS 2010; 1799:28-36. [PMID: 20123066 DOI: 10.1016/j.bbagrm.2009.11.009] [Citation(s) in RCA: 52] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/30/2009] [Revised: 10/26/2009] [Accepted: 11/03/2009] [Indexed: 12/26/2022]
Abstract
High mobility group (HMG) proteins assume important roles in regulating chromatin dynamics, transcriptional activities of genes and other cellular processes. Post-translational modifications of HMG proteins can alter their interactions with DNA and proteins, and consequently, affect their biological activities. Although the mechanisms through which these modifications are involved in regulating biological processes in different cellular contexts are not fully understood, new insights into these modification "codes" have emerged from the increasing appreciation of the functions of these proteins. In this review, we focus on the chemical modifications of mammalian HMG proteins and highlight their roles in nuclear functions.
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Affiliation(s)
- Qingchun Zhang
- Department of Chemistry, University of California, Riverside, CA 92521-0403, USA
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Carneiro VC, de Moraes Maciel R, de Abreu da Silva IC, da Costa RFM, Paiva CN, Bozza MT, Fantappié MR. The extracellular release of Schistosoma mansoni HMGB1 nuclear protein is mediated by acetylation. Biochem Biophys Res Commun 2009; 390:1245-9. [DOI: 10.1016/j.bbrc.2009.10.129] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2009] [Accepted: 10/26/2009] [Indexed: 11/16/2022]
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Gerlitz G, Hock R, Ueda T, Bustin M. The dynamics of HMG protein-chromatin interactions in living cells. Biochem Cell Biol 2009; 87:127-37. [PMID: 19234529 PMCID: PMC3459335 DOI: 10.1139/o08-110] [Citation(s) in RCA: 69] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
The dynamic interaction between nuclear proteins and chromatin leads to the functional plasticity necessary to mount adequate responses to regulatory signals. Here, we review the factors regulating the chromatin interactions of the high mobility group proteins (HMGs), an abundant and ubiquitous superfamily of chromatin-binding proteins in living cells. HMGs are highly mobile and interact with the chromatin fiber in a highly dynamic fashion, as part of a protein network. The major factors that affect the binding of HMGs to chromatin are operative at the level of the single nucleosome. These factors include structural features of the HMGs, competition with other chromatin-binding proteins for nucleosome binding sites, complex formation with protein partners, and post-translational modifications in the protein or in the chromatin-binding sites. The versatile modulation of the interaction between HMG proteins and chromatin plays a role in processes that establish the cellular phenotype.
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Affiliation(s)
- Gabi Gerlitz
- Protein Section, Laboratory of Metabolism, National Cancer Institute, US National Institute of Health, 37 Convent Drive, Bldg. 37, Bethesda, MD 20892, USA
| | - Robert Hock
- Department of Cell and Developmental Biology, Biocenter, University of Wuerzburg, Am Hubland, D-97074, Germany
| | - Tetsuya Ueda
- Protein Section, Laboratory of Metabolism, National Cancer Institute, US National Institute of Health, 37 Convent Drive, Bldg. 37, Bethesda, MD 20892, USA
| | - Michael Bustin
- Protein Section, Laboratory of Metabolism, National Cancer Institute, US National Institute of Health, 37 Convent Drive, Bldg. 37, Bethesda, MD 20892, USA
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Liu H, Yao YM, Ding LH, Zhang H, Yuan B, Song Q, Ye QN, Huang CF, Sheng ZY. High mobility group box-1 protein acts as a coactivator of nuclear factor of activated T cells-2 in promoting interleukin-2 transcription. Int J Biochem Cell Biol 2008; 41:641-8. [PMID: 18707018 DOI: 10.1016/j.biocel.2008.07.009] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2008] [Revised: 07/06/2008] [Accepted: 07/22/2008] [Indexed: 11/15/2022]
Abstract
High mobility group box-1 protein, an abundant and conserved constituent of vertebrate nuclei, has recently been reported to be an endogenous immune signal [Rovere-Querini P, Capobianco A, Scaffidi P, Valentinis B, Catalanotti F, Giazzon M, et al. HMGB1 is an endogenous immune adjuvant released by necrotic cells. EMBO Reports 2004;5:825-30]. High mobility group box-1 protein can trigger the release of interleukin-2 and interleukin-12 from lymphocytes. However, at present the underlying mechanism remains unknown. It has been clarified that nuclear factor of activated T cells-2 transduces most immunological signals in T cells and modulates the production of interleukin-2. So it is natural that we asked whether high mobility group box-1 protein could promote production of interleukin-2 in a nuclear factor of activated T cells-2-dependent way. Our experiments firstly showed that high mobility group box-1 protein could bind to nuclear factor of activated T cells-2 in vivo and in vitro. High mobility group box-1 protein cotransfection markedly upregulated the transcription activity of nuclear factor of activated T cells-2 in promoting interleukin-2 reporter gene transcription, which was demonstrated to be dose-dependent. Cotransfection of high mobility group box-1 protein and nuclear factor of activated T cells-2 induced an 18.4-time increase of interleukin-2 activity in 293T cells and a 117.7-time increase in Hela cells. Moreover, inhibition of either high mobility group box-1 protein or nuclear factor of activated T cells -2 expression by sRNAi led to significant decrease of transcription activity of interleukin-2 reporter gene, suggesting that high mobility group box-1 protein and nuclear factor of activated T cells-2 both take important roles in facilitating interleukin-2 transcription, and high mobility group box-1 protein could act as a coactivator for nuclear factor of activated T cells-2 in enhancing transcription of interleukin-2. This discovery has not been reported elsewhere, and helps to understand the newly highlighted immunological role of high mobility group box-1 protein.
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Affiliation(s)
- Hui Liu
- Surgical Intensive Care Unit, Chinese PLA General Hospital, Beijing 100853, PR China
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