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Cherney RE, Eberhard QE, Giri G, Mills CA, Porrello A, Zhang Z, White D, Trotman JB, Herring LE, Dominguez D, Calabrese JM. SAFB associates with nascent RNAs and can promote gene expression in mouse embryonic stem cells. RNA (NEW YORK, N.Y.) 2023; 29:1535-1556. [PMID: 37468167 PMCID: PMC10578485 DOI: 10.1261/rna.079569.122] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/21/2022] [Accepted: 06/23/2023] [Indexed: 07/21/2023]
Abstract
Scaffold attachment factor B (SAFB) is a conserved RNA-binding protein that is essential for early mammalian development. However, the functions of SAFB in mouse embryonic stem cells (ESCs) have not been characterized. Using RNA immunoprecipitation followed by RNA-seq (RIP-seq), we examined the RNAs associated with SAFB in wild-type and SAFB/SAFB2 double-knockout ESCs. SAFB predominantly associated with introns of protein-coding genes through purine-rich motifs. The transcript most enriched in SAFB association was the lncRNA Malat1, which also contains a purine-rich region in its 5' end. Knockout of SAFB/SAFB2 led to differential expression of approximately 1000 genes associated with multiple biological processes, including apoptosis, cell division, and cell migration. Knockout of SAFB/SAFB2 also led to splicing changes in a set of genes that were largely distinct from those that exhibited changes in expression level. The spliced and nascent transcripts of many genes whose expression levels were positively regulated by SAFB also associated with high levels of SAFB, implying that SAFB binding promotes their expression. Reintroduction of SAFB into double-knockout cells restored gene expression toward wild-type levels, an effect again observable at the level of spliced and nascent transcripts. Proteomics analysis revealed a significant enrichment of nuclear speckle-associated and RS domain-containing proteins among SAFB interactors. Neither Xist nor Polycomb functions were dramatically altered in SAFB/2 knockout ESCs. Our findings suggest that among other potential functions in ESCs, SAFB promotes the expression of certain genes through its ability to bind nascent RNA.
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Affiliation(s)
- Rachel E Cherney
- Department of Pharmacology, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina 27599, USA
- RNA Discovery Center, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina 27599, USA
- Lineberger Comprehensive Cancer Center, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina 27599, USA
- Curriculum in Genetics and Molecular Biology, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina 27599, USA
| | - Quinn E Eberhard
- Department of Pharmacology, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina 27599, USA
- RNA Discovery Center, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina 27599, USA
- Lineberger Comprehensive Cancer Center, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina 27599, USA
- Curriculum in Bioinformatics and Computational Biology, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina 27599, USA
| | - Gilbert Giri
- Department of Pharmacology, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina 27599, USA
- RNA Discovery Center, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina 27599, USA
- Lineberger Comprehensive Cancer Center, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina 27599, USA
- Curriculum in Bioinformatics and Computational Biology, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina 27599, USA
| | - Christine A Mills
- Department of Pharmacology, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina 27599, USA
- Proteomics Core Facility, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina 27599, USA
| | - Alessandro Porrello
- RNA Discovery Center, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina 27599, USA
- Lineberger Comprehensive Cancer Center, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina 27599, USA
| | - Zhiyue Zhang
- Department of Biology, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina 27599, USA
- Department of Computer Science, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina 27599, USA
| | - David White
- Department of Biology, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina 27599, USA
- Department of Computer Science, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina 27599, USA
| | - Jackson B Trotman
- Department of Pharmacology, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina 27599, USA
- RNA Discovery Center, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina 27599, USA
- Lineberger Comprehensive Cancer Center, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina 27599, USA
| | - Laura E Herring
- Department of Pharmacology, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina 27599, USA
- Proteomics Core Facility, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina 27599, USA
| | - Daniel Dominguez
- Department of Pharmacology, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina 27599, USA
- RNA Discovery Center, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina 27599, USA
- Lineberger Comprehensive Cancer Center, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina 27599, USA
| | - J Mauro Calabrese
- Department of Pharmacology, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina 27599, USA
- RNA Discovery Center, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina 27599, USA
- Lineberger Comprehensive Cancer Center, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina 27599, USA
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2
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Agrawal-Singh S, Bagri J, Giotopoulos G, Azazi DMA, Horton SJ, Lopez CK, Anand S, Bach AS, Stedham F, Antrobus R, Houghton JW, Vassiliou GS, Sasca D, Yun H, Whetton AD, Huntly BJP. HOXA9 forms a repressive complex with nuclear matrix-associated protein SAFB to maintain acute myeloid leukemia. Blood 2023; 141:1737-1754. [PMID: 36577137 PMCID: PMC10113176 DOI: 10.1182/blood.2022016528] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2022] [Revised: 11/07/2022] [Accepted: 11/28/2022] [Indexed: 12/29/2022] Open
Abstract
HOXA9 is commonly upregulated in acute myeloid leukemia (AML), in which it confers a poor prognosis. Characterizing the protein interactome of endogenous HOXA9 in human AML, we identified a chromatin complex of HOXA9 with the nuclear matrix attachment protein SAFB. SAFB perturbation phenocopied HOXA9 knockout to decrease AML proliferation, increase differentiation and apoptosis in vitro, and prolong survival in vivo. Integrated genomic, transcriptomic, and proteomic analyses further demonstrated that the HOXA9-SAFB (H9SB)-chromatin complex associates with nucleosome remodeling and histone deacetylase (NuRD) and HP1γ to repress the expression of factors associated with differentiation and apoptosis, including NOTCH1, CEBPδ, S100A8, and CDKN1A. Chemical or genetic perturbation of NuRD and HP1γ-associated catalytic activity also triggered differentiation, apoptosis, and the induction of these tumor-suppressive genes. Importantly, this mechanism is operative in other HOXA9-dependent AML genotypes. This mechanistic insight demonstrates the active HOXA9-dependent differentiation block as a potent mechanism of disease maintenance in AML that may be amenable to therapeutic intervention by targeting the H9SB interface and/or NuRD and HP1γ activity.
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Affiliation(s)
- Shuchi Agrawal-Singh
- Wellcome Trust-MRC Cambridge Stem Cell Institute, Cambridge, United Kingdom
- Department of Haematology, University of Cambridge, Cambridge, United Kingdom
| | - Jaana Bagri
- Wellcome Trust-MRC Cambridge Stem Cell Institute, Cambridge, United Kingdom
- Department of Haematology, University of Cambridge, Cambridge, United Kingdom
| | - George Giotopoulos
- Wellcome Trust-MRC Cambridge Stem Cell Institute, Cambridge, United Kingdom
- Department of Haematology, University of Cambridge, Cambridge, United Kingdom
| | - Dhoyazan M A Azazi
- Wellcome Trust-MRC Cambridge Stem Cell Institute, Cambridge, United Kingdom
- Department of Haematology, University of Cambridge, Cambridge, United Kingdom
| | - Sarah J Horton
- Wellcome Trust-MRC Cambridge Stem Cell Institute, Cambridge, United Kingdom
- Department of Haematology, University of Cambridge, Cambridge, United Kingdom
| | - Cecile K Lopez
- Wellcome Trust-MRC Cambridge Stem Cell Institute, Cambridge, United Kingdom
- Department of Haematology, University of Cambridge, Cambridge, United Kingdom
| | - Shubha Anand
- Cancer Molecular Diagnostics Laboratory, Cancer Research UK Cambridge Centre, Cambridge, United Kingdom
| | - Anne-Sophie Bach
- Wellcome Trust-MRC Cambridge Stem Cell Institute, Cambridge, United Kingdom
- Department of Haematology, University of Cambridge, Cambridge, United Kingdom
| | - Frances Stedham
- Wellcome Trust-MRC Cambridge Stem Cell Institute, Cambridge, United Kingdom
- Department of Haematology, University of Cambridge, Cambridge, United Kingdom
| | - Robin Antrobus
- Cambridge Institute for Medical Research, University of Cambridge, Cambridge, United Kingdom
| | - Jack W Houghton
- Cambridge Institute for Medical Research, University of Cambridge, Cambridge, United Kingdom
| | - George S Vassiliou
- Wellcome Trust-MRC Cambridge Stem Cell Institute, Cambridge, United Kingdom
- Department of Haematology, University of Cambridge, Cambridge, United Kingdom
- Cambridge University Hospitals NHS Foundation Trust, Cambridge, United Kingdom
| | - Daniel Sasca
- Department of Hematology, Oncology and Pneumology, University Medical Center Mainz, Mainz, Germany
| | - Haiyang Yun
- Department of Medicine V, Hematology, Oncology and Rheumatology, University of Heidelberg, Heidelberg, Germany
| | - Anthony D Whetton
- School of Veterinary Medicine, School of Biosciences and Medicine, University of Surrey, Guildford, Surrey, United Kingdom
| | - Brian J P Huntly
- Wellcome Trust-MRC Cambridge Stem Cell Institute, Cambridge, United Kingdom
- Department of Haematology, University of Cambridge, Cambridge, United Kingdom
- Cambridge Institute for Medical Research, University of Cambridge, Cambridge, United Kingdom
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Spatiotemporal Regulation and Functional Analysis of Circular RNAs in Skeletal Muscle and Subcutaneous Fat during Pig Growth. BIOLOGY 2021; 10:biology10090841. [PMID: 34571718 PMCID: PMC8465536 DOI: 10.3390/biology10090841] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/05/2021] [Revised: 08/25/2021] [Accepted: 08/25/2021] [Indexed: 11/16/2022]
Abstract
Recently, thousands of circular RNAs have been reported in different pig breeds. However, researches on the temporal and spatial expression patterns of circRNA over the period of animal growth are limited. Here, we systematically analyzed circRNAs in skeletal muscle and subcutaneous fat in four growth time points (30 days, 90 days, 150 days and 210 days after birth) of a Chinese native pig breed, Ningxiang pigs. A total of 1171 differentially expressed (DE) circRNAs between muscle and fat were identified, including 562 upregulated and 609 downregulated circRNAs. KEGG pathway enrichment analysis of these DE circRNAs revealed that host genes were mainly involved in glycogen metabolism signaling pathways, muscle development signaling pathways such as ErbB pathway and adipocytokine signaling pathways and AMPK signaling pathways and fatty acid biosynthesis. The circRNAs have striking spatiotemporal specificity in the form of dynamic expression at 90 d. Short Time-Series Expression Miner analysis showed multiple model spectra that are significantly enriched with time changes in muscle and fat. Our findings provide new ideas and perspectives about the role of circular RNAs and their targeting relations with mRNA and miRNA in skeletal muscle and fat tissue during pig growth.
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Subcellular dynamics of estrogen-related receptors involved in transrepression through interactions with scaffold attachment factor B1. Histochem Cell Biol 2021; 156:239-251. [PMID: 34129097 DOI: 10.1007/s00418-021-01998-7] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 05/26/2021] [Indexed: 12/31/2022]
Abstract
Estrogen-related receptor (ERR), a member of the nuclear receptor superfamily, consists of three subtypes (α, β, γ) and has strong homology with estrogen receptor. No endogenous ligands have been identified for ERRs, but they play key roles in metabolic, hormonal, and developmental processes as transcription factors without ligand binding. Although subnuclear dynamics are essential for nuclear events including nuclear receptor-mediated transcriptional regulation, the dynamics of ERRs are poorly understood. Here, we report that ERRs show subcellular kinetic changes in response to diethylstilbestrol (DES), a synthetic estrogen that represses the transactivity of all three ERR subtypes, using live-cell imaging with fluorescent protein labeling. Upon DES treatment, all ERR subtypes formed discrete clusters in the nucleus, with ERRγ also displaying nuclear export. Fluorescence recovery after photobleaching analyses revealed significant reductions in the intranuclear mobility of DES-bound ERRα and ERRβ, and a slight reduction in the intranuclear mobility of DES-bound ERRγ. After DES treatment, colocalization of all ERR subtypes with scaffold attachment factor B1 (SAFB1), a nuclear matrix-associated protein, was observed in dot-like subnuclear clusters, suggesting interactions of the ERRs with the nuclear matrix. Consistently, co-immunoprecipitation analyses confirmed enhanced interactions between ERRs and SAFB1 in the presence of DES. SAFB1 was clarified to repress the transactivity of all ERR subtypes through the ERR-response element. These results demonstrate ligand-dependent cluster formation of ERRs in the nucleus that is closely associated with SAFB1-mediated transrepression. Taken together, the present findings provide a new understanding of the pathophysiology regulated by ERR/SAFB1 signaling pathways and their subcellular dynamics.
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Su H, Liu D, Shao J, Li Y, Wang X, Gao Q. Aging Liver: Can Exercise be a Better Way to Delay the Process than Nutritional and Pharmacological Intervention? Focus on Lipid Metabolism. Curr Pharm Des 2021; 26:4982-4991. [PMID: 32503400 DOI: 10.2174/1381612826666200605111232] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2020] [Accepted: 05/18/2020] [Indexed: 12/12/2022]
Abstract
BACKGROUND & AIMS Nowadays, the world is facing a common problem that the population aging process is accelerating. How to delay metabolic disorders in middle-aged and elderly people, has become a hot scientific and social issue worthy of attention. The liver plays an important role in lipid metabolism, and abnormal lipid metabolism may lead to liver diseases. Exercise is an easily controlled and implemented intervention, which has attracted extensive attention in improving the health of liver lipid metabolism in the elderly. This article reviewed the body aging process, changes of lipid metabolism in the aging liver, and the mechanism and effects of different interventions on lipid metabolism in the aging liver, especially focusing on exercise intervention. METHODS A literature search was performed using PubMed-NCBI, EBSCO Host and Web of Science, and also a report from WHO. In total, 143 studies were included from 1986 to 15 February 2020. CONCLUSION Nutritional and pharmacological interventions can improve liver disorders, and nutritional interventions are less risky relatively. Exercise intervention can prevent and improve age-related liver disease, especially the best high-intensity interval training intensity and duration is expected to be one of the research directions in the future.
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Affiliation(s)
- Hao Su
- The School of Sport Science, Beijing Sport University, Beijing, China
| | - Dongsen Liu
- The School of Sports Medicine and Rehabilitation, Beijing Sport University, Beijing, China
| | - Jia Shao
- The Graduate School, Beijing Sport University, Beijing, China
| | - Yinuo Li
- The Graduate School, Beijing Sport University, Beijing, China
| | - Xiaoxia Wang
- The School of Physical Education and Art Education, Beijing Technology and Business University, Beijing, China
| | - Qi Gao
- The School of Sports Medicine and Rehabilitation, Beijing Sport University, Beijing, China
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6
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Jones K, Zhang Y, Kong Y, Farah E, Wang R, Li C, Wang X, Zhang Z, Wang J, Mao F, Liu X, Liu J. Epigenetics in prostate cancer treatment. JOURNAL OF TRANSLATIONAL GENETICS AND GENOMICS 2021; 5:341-356. [PMID: 35372800 PMCID: PMC8974353 DOI: 10.20517/jtgg.2021.19] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
Prostate cancer (PCa) is the most commonly diagnosed malignancy among men, and the progression of this disease results in fewer treatment options available to clinical patients. It highlights the vital necessity for discovering novel therapeutic approaches and expanding the current understanding of molecular mechanisms. Epigenetic alternations such as DNA methylation models and histone modifications have been associated as key drivers in the development and advancement of PCa. Several studies have been conducted and demonstrated that targeting these epigenetic enzymes or regulatory proteins has been strongly associated with the regulation of cancer cell growth. Due to the success rate of these therapeutic routes in pre-clinical settings, many drugs have now advanced to clinical testing, where efficacy will be measured. This review will discuss the role of epigenetic modifications in PCa development and its function in the progression of the disease to resistant forms and introduce therapeutic strategies that have demonstrated successful results as PCa treatment.
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Affiliation(s)
- Katelyn Jones
- Department of Toxicology and Cancer Biology, University of Kentucky, Lexington, KY 40536, USA
| | - Yanquan Zhang
- Department of Toxicology and Cancer Biology, University of Kentucky, Lexington, KY 40536, USA
| | - Yifan Kong
- Department of Toxicology and Cancer Biology, University of Kentucky, Lexington, KY 40536, USA
| | - Elia Farah
- Department of Biochemistry, Purdue University, West Lafayette, IN 47907, USA
| | - Ruixin Wang
- Department of Toxicology and Cancer Biology, University of Kentucky, Lexington, KY 40536, USA
| | - Chaohao Li
- Department of Toxicology and Cancer Biology, University of Kentucky, Lexington, KY 40536, USA
| | - Xinyi Wang
- Department of Toxicology and Cancer Biology, University of Kentucky, Lexington, KY 40536, USA
| | - ZhuangZhuang Zhang
- Department of Toxicology and Cancer Biology, University of Kentucky, Lexington, KY 40536, USA
| | - Jianlin Wang
- Department of Toxicology and Cancer Biology, University of Kentucky, Lexington, KY 40536, USA
| | - Fengyi Mao
- Department of Toxicology and Cancer Biology, University of Kentucky, Lexington, KY 40536, USA
| | - Xiaoqi Liu
- Department of Toxicology and Cancer Biology, University of Kentucky, Lexington, KY 40536, USA.,Markey Cancer Center, University of Kentucky, Lexington, KY 40536, USA
| | - Jinghui Liu
- Department of Toxicology and Cancer Biology, University of Kentucky, Lexington, KY 40536, USA
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7
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Li M, Gan J, Sun Y, Xu Z, Yang J, Sun Y, Li C. Architectural proteins for the formation and maintenance of the 3D genome. SCIENCE CHINA. LIFE SCIENCES 2020; 63:795-810. [PMID: 32249389 DOI: 10.1007/s11427-019-1613-3] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/04/2019] [Accepted: 12/26/2019] [Indexed: 12/20/2022]
Abstract
Eukaryotic genomes are densely packaged into hierarchical three-dimensional (3D) structures that contain information about gene regulation and many other biological processes. With the development of imaging and sequencing-based technologies, 3D genome studies have revealed that the high-order chromatin structure is composed of hierarchical levels, including chromosome territories, A/B compartments, topologically associated domains, and chromatin loops. However, how this chromatin architecture is formed and maintained is not completely clear. In this review, we introduce experimental methods to investigate the 3D genome, review major architectural proteins that regulate 3D chromatin organization in mammalian cells, such as CTCF (CCCTC-binding factor), cohesin, lamins, and transcription factors, and discuss relevant mechanisms such as phase separation.
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Affiliation(s)
- Mengfan Li
- Peking-Tsinghua Center for Life Sciences, Academy for Advanced Interdisciplinary Studies; School of Life Sciences, Peking University, Beijing, 100871, China
| | - Jingbo Gan
- Peking-Tsinghua Center for Life Sciences, Academy for Advanced Interdisciplinary Studies; School of Life Sciences, Peking University, Beijing, 100871, China
| | - Yuao Sun
- Peking-Tsinghua Center for Life Sciences, Academy for Advanced Interdisciplinary Studies; School of Life Sciences, Peking University, Beijing, 100871, China
- State Key Laboratory of Membrane Biology, School of Life Sciences; Biomedical Pioneering Innovation Center (BIOPIC), Peking University, Beijing, 100871, China
| | - Zihan Xu
- Peking-Tsinghua Center for Life Sciences, Academy for Advanced Interdisciplinary Studies; School of Life Sciences, Peking University, Beijing, 100871, China
| | - Junsheng Yang
- Peking-Tsinghua Center for Life Sciences, Academy for Advanced Interdisciplinary Studies; School of Life Sciences, Peking University, Beijing, 100871, China
- State Key Laboratory of Membrane Biology, School of Life Sciences; Biomedical Pioneering Innovation Center (BIOPIC), Peking University, Beijing, 100871, China
| | - Yujie Sun
- State Key Laboratory of Membrane Biology, School of Life Sciences; Biomedical Pioneering Innovation Center (BIOPIC), Peking University, Beijing, 100871, China.
| | - Cheng Li
- Center for Statistical Science, Center for Bioinformatics, School of Life Sciences, Peking University, Beijing, 100871, China.
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8
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Scaffold attachment factor B: distribution and interaction with ERα in the rat brain. Histochem Cell Biol 2020; 153:323-338. [PMID: 32086573 DOI: 10.1007/s00418-020-01853-1] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 02/07/2020] [Indexed: 10/24/2022]
Abstract
Scaffold attachment factor (SAFB) 1 and its homologue SAFB2 are multifunctional proteins that are involved in various cellular mechanisms, including chromatin organization and transcriptional regulation, and are also corepressors of estrogen receptor alpha (ERα). Both SAFBs are expressed at high levels in the brain. However, the distributions of SAFB1 and SAFB2 have yet to be characterized in detail and it is unclear whether both proteins interact with ERα in the brain. In this study, we investigated the expression and distribution of both SAFBs and their interaction with ERα in adult male rat brain. Immunohistochemical staining showed that SAFB1 and SAFB2 have a similar distribution pattern and are widely expressed throughout the brain. Double-fluorescence immunohistochemical and immunocytochemical analyses in primary cultures showed that the two SAFB proteins are localized in nuclei of neurons, astrocytes, and oligodendrocytes. Of note, SAFB2 was also found in cytoplasmic regions in these cell lineages. Both SAFB proteins were also expressed in ERα-positive cells in the medial preoptic area (MPOA) and arcuate and ventromedial hypothalamic nuclei. Co-immunoprecipitation experiments revealed that both SAFB proteins from the MPOA reciprocally interact with endogenous ERα. These results indicate that, in addition to a role in basal cellular function in the brain, the SAFB proteins may serve as ERα corepressors in hormone-sensitive regions.
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9
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Kumar S, Egan BM, Kocsisova Z, Schneider DL, Murphy JT, Diwan A, Kornfeld K. Lifespan Extension in C. elegans Caused by Bacterial Colonization of the Intestine and Subsequent Activation of an Innate Immune Response. Dev Cell 2019; 49:100-117.e6. [PMID: 30965033 DOI: 10.1016/j.devcel.2019.03.010] [Citation(s) in RCA: 70] [Impact Index Per Article: 14.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2018] [Revised: 02/04/2019] [Accepted: 03/12/2019] [Indexed: 10/27/2022]
Abstract
Mechanisms that control aging are important yet poorly defined. To discover longevity control genes, we performed a forward genetic screen for delayed reproductive aging in C. elegans. Here, we show that am117 is a nonsense mutation in the phm-2 gene, which encodes a protein homologous to human scaffold attachment factor B. phm-2(lf) mutant worms have an abnormal pharynx grinder, which allows live bacteria to accumulate in the intestine. This defect shortens lifespan on highly pathogenic bacteria but extends lifespan and health span on the standard E. coli diet by activating innate immunity pathways that lead to bacterial avoidance behavior and dietary restriction. eat-2(lf) mutants displayed a similar phenotype, indicating accumulation of live bacteria also triggers extended longevity in this mutant. The analysis of phm-2 elucidates connections between pathogen response and aging by defining a mechanism of longevity extension in C. elegans-bacterial colonization, innate immune activation, and bacterial avoidance behavior.
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Affiliation(s)
- Sandeep Kumar
- Department of Developmental Biology, Washington University School of Medicine, St. Louis, MO 63110, USA; Division of Bone & Mineral Diseases, Department of Internal Medicine, Washington University School of Medicine, St. Louis, MO 63110, USA
| | - Brian M Egan
- Department of Developmental Biology, Washington University School of Medicine, St. Louis, MO 63110, USA
| | - Zuzana Kocsisova
- Department of Developmental Biology, Washington University School of Medicine, St. Louis, MO 63110, USA
| | - Daniel L Schneider
- Department of Developmental Biology, Washington University School of Medicine, St. Louis, MO 63110, USA
| | - John T Murphy
- Center for Cardiovascular Research and Division of Cardiology, Department of Internal Medicine, Washington University School of Medicine, St. Louis, MO 63110, USA
| | - Abhinav Diwan
- Center for Cardiovascular Research and Division of Cardiology, Department of Internal Medicine, Washington University School of Medicine, St. Louis, MO 63110, USA
| | - Kerry Kornfeld
- Department of Developmental Biology, Washington University School of Medicine, St. Louis, MO 63110, USA.
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Zhang Z, Zhan X, Kim B, Wu J. A proteomic approach identifies SAFB-like transcription modulator (SLTM) as a bidirectional regulator of GLI family zinc finger transcription factors. J Biol Chem 2019; 294:5549-5561. [PMID: 30782847 DOI: 10.1074/jbc.ra118.007018] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2018] [Revised: 02/11/2019] [Indexed: 01/20/2023] Open
Abstract
In Sonic hedgehog (SHH) signaling, GLI family zinc finger (GLI)-mediated diverse gene transcription outcomes are strictly regulated and are important for SHH function in both development and disease. However, how the GLI factors differentially regulate transcription in response to variable SHH activities is incompletely understood. Here, using a newly generated, tagged Gli3 knock-in mouse (Gli3TAP ), we performed proteomic analyses and identified the chromatin-associated SAFB-like transcription modulator (SLTM) as a GLI-interacting protein that context-dependently regulates GLI activities. Using immunoprecipitation and immunoblotting, RT-quantitative PCR, and ChIP assays, we show that SLTM interacts with all three GLI proteins and that its cellular levels are regulated by SHH. We also found that SLTM enhances GLI3 binding to chromatin and increases GLI3 repressor (GLI3R) form protein levels. In a GLI3-dependent manner, SLTM promoted the formation of a repressive chromatin environment and functioned as a GLI3 co-repressor. In the absence of GLI3 or in the presence of low GLI3 levels, SLTM co-activated GLI activator (GLIA)-mediated target gene activation and cell differentiation. Moreover, in vivo Sltm deletion generated through CRISPR/Cas9-mediated gene editing caused perinatal lethality and SHH-related abnormal ventral neural tube phenotypes. We conclude that SLTM regulates GLI factor binding to chromatin and contributes to the transcriptional outcomes of SHH signaling via a novel molecular mechanism.
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Affiliation(s)
| | - Xiaoming Zhan
- From the Department of Physiology and.,Center for the Genetics of Host Defense, University of Texas Southwestern Medical Center, Dallas, Texas 75390
| | | | - Jiang Wu
- From the Department of Physiology and
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11
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Matsuda KI, Hashimoto T, Kawata M. Intranuclear Mobility of Estrogen Receptor: Implication for Transcriptional Regulation. Acta Histochem Cytochem 2018; 51:129-136. [PMID: 30279614 PMCID: PMC6160615 DOI: 10.1267/ahc.18023] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2018] [Accepted: 07/31/2018] [Indexed: 11/22/2022] Open
Abstract
The estrogen receptor (ER) is a ligand-dependent transcription factor that has two subtypes: ERα and ERβ. ERs regulate transcription of estrogen-responsive genes through interactions with multiple intranuclear components, such as cofactors and the nuclear matrix. Live cell imaging using fluorescent protein-labeled ERs has revealed that ligand-activated ERs are highly mobile in the nucleus, with transient association with the DNA and nuclear matrix. Scaffold attachment factor B (SAFB) 1 and its paralogue, SAFB2, are nuclear matrix-binding proteins that negatively modulate ERα-mediated transcription. Expression of SAFB1 and SAFB2 reduces the mobility of ERα in the presence of ligand. This regulatory machinery is emerging as an epigenetic-like mechanism that alters transcriptional activity through control of intranuclear molecular mobility.
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Affiliation(s)
- Ken Ichi Matsuda
- Department of Anatomy and Neurobiology, Graduate School of Medical Science, Kyoto Prefectural University of Medicine
| | - Takashi Hashimoto
- Division of Anatomy and Neuroscience, Department of Morphological and Physiological Sciences, University of Fukui Faculty of Medical Sciences
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12
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Ma'ayeh SY, Knörr L, Sköld K, Garnham A, Ansell BRE, Jex AR, Svärd SG. Responses of the Differentiated Intestinal Epithelial Cell Line Caco-2 to Infection With the Giardia intestinalis GS Isolate. Front Cell Infect Microbiol 2018; 8:244. [PMID: 30062089 PMCID: PMC6055019 DOI: 10.3389/fcimb.2018.00244] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2018] [Accepted: 06/25/2018] [Indexed: 12/11/2022] Open
Abstract
Giardia intestinalis is a parasitic protist that causes diarrhea in humans, affecting mainly children of the developing world, elderly and immunocompromised individuals. Humans are infected by two major Giardia assemblages (i.e. genetic subtypes), A and B, with the latter being the most common. So far, there is little information on molecular or cellular changes during infections with assemblage B. Here, we used RNA sequencing to study transcriptional changes in Caco-2 intestinal epithelial cells (IECs) co-incubated with assemblage B (GS isolate) trophozoites for 1.5, 3, and 4.5 h. We aimed to identify early molecular events associated with the establishment of infection and followed cellular protein changes up to 10 h. IEC transcriptomes showed a dominance of immediate early response genes which was sustained across all time points. Transcription of inflammatory cytokines (e.g., cxcl1-3, ccl2, 1l1a, and il1b) peaked at 1.5 and 3 h of infection. Compared to co-incubation with assemblage A Giardia, we identified the induction of novel cytokines (cxcl8, cxcl10, csf1, cx3cl1, il12a, il11) and showed that inflammatory signaling is mediated by Erk1/2 phosphorylation (mitogen activated protein kinase, MAPK), nuclear factor kappa B (NFκB) and adaptor protein-1 (AP-1). We also showed that GS trophozoites attenuate P38 (MAPK) phosphorylation in IECs. Low amounts of IL-8, CXCL1 and CCL20 proteins were measured in the interaction medium, which was attributed to cytokine degradation by trophozoite secreted proteases. Based on the transcriptome, the decay of cytokines mRNA mediated by zinc finger protein 36 might be another mechanism controlling cytokine levels at later time points. IEC transcriptomes suggested homeostatic responses to counter oxidative stress, glucose starvation, and disturbances in amino acid and lipid metabolism. A large group of differentially transcribed genes were associated with cell cycle arrest and induction of apoptosis, which was validated at protein level. IEC transcriptomes also suggested changes in tight junction's integrity, microvilli structure and the extracellular mucin layer. This is the first study to illuminate transcriptional and protein regulatory events underlying IECs responses and pathogenesis during Giardia assemblage B infection. It highlights differences compared to assemblage A infections which might account for the differences observed in human infections with the two assemblages.
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Affiliation(s)
- Showgy Y Ma'ayeh
- Department of Cell and Molecular Biology, Uppsala University, Uppsala, Sweden
| | - Livia Knörr
- Department of Cell and Molecular Biology, Uppsala University, Uppsala, Sweden
| | - Karin Sköld
- Department of Cell and Molecular Biology, Uppsala University, Uppsala, Sweden
| | - Alexandra Garnham
- Population Health & Immunity Division, The Walter and Eliza Hall Institute of Medical Research, Parkville, VIC, Australia
| | - Brendan R E Ansell
- Population Health & Immunity Division, The Walter and Eliza Hall Institute of Medical Research, Parkville, VIC, Australia.,Faculty of Veterinary Science, The University of Melbourne, Parkville, VIC, Australia
| | - Aaron R Jex
- Population Health & Immunity Division, The Walter and Eliza Hall Institute of Medical Research, Parkville, VIC, Australia.,Faculty of Veterinary Science, The University of Melbourne, Parkville, VIC, Australia
| | - Staffan G Svärd
- Department of Cell and Molecular Biology, Uppsala University, Uppsala, Sweden
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13
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Ma L, Sun L, Jin X, Xiong SD, Wang JH. Scaffold attachment factor B suppresses HIV-1 infection of CD4 + T cells by preventing binding of RNA polymerase II to HIV-1's long terminal repeat. J Biol Chem 2018; 293:12177-12185. [PMID: 29887524 DOI: 10.1074/jbc.ra118.002018] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2018] [Revised: 06/01/2018] [Indexed: 12/19/2022] Open
Abstract
The 5' end of the HIV, type 1 (HIV-1) long terminal repeat (LTR) promoter plays an essential role in driving viral transcription and productive infection. Multiple host and viral factors regulate LTR activity and modulate HIV-1 latency. Manipulation of the HIV-1 LTR provides a potential therapeutic strategy for combating HIV-1 persistence. In this study, we identified an RNA/DNA-binding protein, scaffold attachment factor B (SAFB1), as a host cell factor that represses HIV-1 transcription. We found that SAFB1 bound to the HIV-1 5' LTR and significantly repressed 5' LTR-driven viral transcription and HIV-1 infection of CD4+ T cells. Mechanistically, SAFB1-mediated repression of HIV-1 transcription and infection was independent of its RNA- and DNA-binding capacities. Instead, by binding to phosphorylated RNA polymerase II, SAFB1 blocked its recruitment to the HIV-1 LTR. Of note, SAFB1-mediated repression of HIV-1 transcription from proviral DNA maintained HIV-1 latency in CD4+ T cells. In summary, our findings reveal that SAFB1 binds to the HIV-1 LTR and physically interacts with phosphorylated RNA polymerase II, repressing HIV-1 transcription initiation and elongation. Our findings improve our understanding of host modulation of HIV-1 transcription and latency and provide a new host cell target for improved anti-HIV-1 therapies.
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Affiliation(s)
- Li Ma
- Jiangsu Key Laboratory of Infection and Immunity, Institutes of Biology and Medical Sciences, Soochow University, Suzhou 215006, China; Chinese Academy of Sciences Key Laboratory of Molecular Virology and Immunology, Institute Pasteur of Shanghai, Chinese Academy of Sciences, Shanghai 200031, China
| | - Li Sun
- Chinese Academy of Sciences Key Laboratory of Molecular Virology and Immunology, Institute Pasteur of Shanghai, Chinese Academy of Sciences, Shanghai 200031, China
| | - Xia Jin
- Chinese Academy of Sciences Key Laboratory of Molecular Virology and Immunology, Institute Pasteur of Shanghai, Chinese Academy of Sciences, Shanghai 200031, China
| | - Si-Dong Xiong
- Jiangsu Key Laboratory of Infection and Immunity, Institutes of Biology and Medical Sciences, Soochow University, Suzhou 215006, China
| | - Jian-Hua Wang
- Chinese Academy of Sciences Key Laboratory of Molecular Virology and Immunology, Institute Pasteur of Shanghai, Chinese Academy of Sciences, Shanghai 200031, China.
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14
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Functional Analysis of Human Hub Proteins and Their Interactors Involved in the Intrinsic Disorder-Enriched Interactions. Int J Mol Sci 2017; 18:ijms18122761. [PMID: 29257115 PMCID: PMC5751360 DOI: 10.3390/ijms18122761] [Citation(s) in RCA: 71] [Impact Index Per Article: 10.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2017] [Revised: 12/13/2017] [Accepted: 12/15/2017] [Indexed: 12/15/2022] Open
Abstract
Some of the intrinsically disordered proteins and protein regions are promiscuous interactors that are involved in one-to-many and many-to-one binding. Several studies have analyzed enrichment of intrinsic disorder among the promiscuous hub proteins. We extended these works by providing a detailed functional characterization of the disorder-enriched hub protein-protein interactions (PPIs), including both hubs and their interactors, and by analyzing their enrichment among disease-associated proteins. We focused on the human interactome, given its high degree of completeness and relevance to the analysis of the disease-linked proteins. We quantified and investigated numerous functional and structural characteristics of the disorder-enriched hub PPIs, including protein binding, structural stability, evolutionary conservation, several categories of functional sites, and presence of over twenty types of posttranslational modifications (PTMs). We showed that the disorder-enriched hub PPIs have a significantly enlarged number of disordered protein binding regions and long intrinsically disordered regions. They also include high numbers of targeting, catalytic, and many types of PTM sites. We empirically demonstrated that these hub PPIs are significantly enriched among 11 out of 18 considered classes of human diseases that are associated with at least 100 human proteins. Finally, we also illustrated how over a dozen specific human hubs utilize intrinsic disorder for their promiscuous PPIs.
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15
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Jiao HL, Ye YP, Yang RW, Sun HY, Wang SY, Wang YX, Xiao ZY, He LQ, Cai JJ, Wei WT, Chen YR, Gu CC, Cai YL, Hu YT, Lai QH, Qiu JF, Liang L, Cao GW, Liao WT, Ding YQ. Downregulation of SAFB Sustains the NF- κB Pathway by Targeting TAK1 during the Progression of Colorectal Cancer. Clin Cancer Res 2017; 23:7108-7118. [PMID: 28912140 DOI: 10.1158/1078-0432.ccr-17-0747] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2017] [Revised: 07/17/2017] [Accepted: 09/07/2017] [Indexed: 11/16/2022]
Abstract
Purpose: To investigate the role and the underlying mechanism of scaffold attachment factor B (SAFB) in the progression of colorectal cancer (CRC).Experimental Design: SAFB expression was analyzed in the Cancer Outlier Profile Analysis of Oncomine and in 175 paraffin-embedded archived CRC tissues. Gene Ontology analyses were performed to explore the mechanism of SAFB in CRC progression. Western blot, RT-PCR, luciferase assay, and chromatin immunoprecipitation (ChIP) were used to detect the regulation of transforming growth factor-β-activated kinase 1 (TAK1) and NF-κB signaling by SAFB The role of SAFB in invasion, metastasis, and angiogenesis was investigated using in vitro and in vivo assays. The relationship between SAFB and TAK1 was analyzed in CRC tissues.Results: SAFB was downregulated in CRC tissues, and low expression of SAFB was significantly associated with an aggressive phenotype and poorer survival of CRC patients. The downregulation of SAFB activated NF-κB signaling by targeting the TAK1 promoter. Ectopic expression of SAFB inhibited the development of aggressive features and metastasis of CRC cells both in vitro and in vivo The overexpression of TAK1 could rescue the aggressive features in SAFB-overexpressed cells. Furthermore, the expression of SAFB in CRC tissues was negatively correlated with the expression of TAK1- and NF-κB-related genes.Conclusions: Our results show that SAFB regulated the activity of NF-κB signaling in CRC by targeting TAK1 This novel mechanism provides a comprehensive understanding of both SAFB and the NF-κB signaling pathway in the progression of CRC and indicates that the SAFB-TAK1-NF-κB axis is a potential target for early therapeutic intervention in CRC progression. Clin Cancer Res; 23(22); 7108-18. ©2017 AACR.
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Affiliation(s)
- Hong-Li Jiao
- Department of Pathology, Nanfang Hospital, Southern Medical University, Guangzhou, China.,Department of Pathology, School of Basic Medical Sciences, Southern Medical University, Guangzhou, China.,Guangdong Provincial Key Laboratory of Molecular Tumor Pathology, Guangzhou, China
| | - Ya-Ping Ye
- Department of Pathology, Nanfang Hospital, Southern Medical University, Guangzhou, China.,Department of Pathology, School of Basic Medical Sciences, Southern Medical University, Guangzhou, China.,Guangdong Provincial Key Laboratory of Molecular Tumor Pathology, Guangzhou, China
| | - Run-Wei Yang
- Department of Pathology, Nanfang Hospital, Southern Medical University, Guangzhou, China.,Department of Pathology, School of Basic Medical Sciences, Southern Medical University, Guangzhou, China.,Guangdong Provincial Key Laboratory of Molecular Tumor Pathology, Guangzhou, China
| | - Hui-Ying Sun
- Department of Pathology, Nanfang Hospital, Southern Medical University, Guangzhou, China.,Department of Pathology, School of Basic Medical Sciences, Southern Medical University, Guangzhou, China.,Guangdong Provincial Key Laboratory of Molecular Tumor Pathology, Guangzhou, China
| | - Shu-Yang Wang
- Department of Pathology, Nanfang Hospital, Southern Medical University, Guangzhou, China.,Department of Pathology, School of Basic Medical Sciences, Southern Medical University, Guangzhou, China.,Guangdong Provincial Key Laboratory of Molecular Tumor Pathology, Guangzhou, China
| | - Yong-Xia Wang
- Department of Pathology, Nanfang Hospital, Southern Medical University, Guangzhou, China.,Department of Pathology, School of Basic Medical Sciences, Southern Medical University, Guangzhou, China.,Guangdong Provincial Key Laboratory of Molecular Tumor Pathology, Guangzhou, China
| | - Zhi-Yuan Xiao
- Department of Pathology, Nanfang Hospital, Southern Medical University, Guangzhou, China.,Department of Pathology, School of Basic Medical Sciences, Southern Medical University, Guangzhou, China.,Guangdong Provincial Key Laboratory of Molecular Tumor Pathology, Guangzhou, China
| | - Liu-Qing He
- Department of Pathology, Nanfang Hospital, Southern Medical University, Guangzhou, China.,Department of Pathology, School of Basic Medical Sciences, Southern Medical University, Guangzhou, China.,Guangdong Provincial Key Laboratory of Molecular Tumor Pathology, Guangzhou, China
| | - Juan-Juan Cai
- Department of Pathology, Nanfang Hospital, Southern Medical University, Guangzhou, China.,Department of Pathology, School of Basic Medical Sciences, Southern Medical University, Guangzhou, China.,Guangdong Provincial Key Laboratory of Molecular Tumor Pathology, Guangzhou, China
| | - Wen-Ting Wei
- Department of Pathology, Nanfang Hospital, Southern Medical University, Guangzhou, China.,Department of Pathology, School of Basic Medical Sciences, Southern Medical University, Guangzhou, China.,Guangdong Provincial Key Laboratory of Molecular Tumor Pathology, Guangzhou, China
| | - Yan-Ru Chen
- Department of Pathology, Nanfang Hospital, Southern Medical University, Guangzhou, China.,Department of Pathology, School of Basic Medical Sciences, Southern Medical University, Guangzhou, China.,Guangdong Provincial Key Laboratory of Molecular Tumor Pathology, Guangzhou, China
| | - Chun-Cai Gu
- Department of Pathology, Nanfang Hospital, Southern Medical University, Guangzhou, China.,Department of Pathology, School of Basic Medical Sciences, Southern Medical University, Guangzhou, China.,Guangdong Provincial Key Laboratory of Molecular Tumor Pathology, Guangzhou, China
| | - Yue-Long Cai
- Department of Pathology, Nanfang Hospital, Southern Medical University, Guangzhou, China.,Department of Pathology, School of Basic Medical Sciences, Southern Medical University, Guangzhou, China.,Guangdong Provincial Key Laboratory of Molecular Tumor Pathology, Guangzhou, China
| | - Yun-Teng Hu
- Department of Pathology, Nanfang Hospital, Southern Medical University, Guangzhou, China.,Department of Pathology, School of Basic Medical Sciences, Southern Medical University, Guangzhou, China.,Guangdong Provincial Key Laboratory of Molecular Tumor Pathology, Guangzhou, China
| | - Qiu-Hua Lai
- Department of Pathology, Nanfang Hospital, Southern Medical University, Guangzhou, China.,Department of Pathology, School of Basic Medical Sciences, Southern Medical University, Guangzhou, China.,Guangdong Provincial Key Laboratory of Molecular Tumor Pathology, Guangzhou, China
| | - Jun-Feng Qiu
- Department of Pathology, Nanfang Hospital, Southern Medical University, Guangzhou, China.,Department of Pathology, School of Basic Medical Sciences, Southern Medical University, Guangzhou, China.,Guangdong Provincial Key Laboratory of Molecular Tumor Pathology, Guangzhou, China
| | - Li Liang
- Department of Pathology, Nanfang Hospital, Southern Medical University, Guangzhou, China.,Department of Pathology, School of Basic Medical Sciences, Southern Medical University, Guangzhou, China.,Guangdong Provincial Key Laboratory of Molecular Tumor Pathology, Guangzhou, China
| | - Guang-Wen Cao
- Department of Epidemiology, Second Military Medical University, Shanghai, China
| | - Wen-Ting Liao
- Department of Pathology, Nanfang Hospital, Southern Medical University, Guangzhou, China. .,Department of Pathology, School of Basic Medical Sciences, Southern Medical University, Guangzhou, China.,Guangdong Provincial Key Laboratory of Molecular Tumor Pathology, Guangzhou, China
| | - Yan-Qing Ding
- Department of Pathology, Nanfang Hospital, Southern Medical University, Guangzhou, China. .,Department of Pathology, School of Basic Medical Sciences, Southern Medical University, Guangzhou, China.,Guangdong Provincial Key Laboratory of Molecular Tumor Pathology, Guangzhou, China
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16
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Proteomics-Based Identification of the Molecular Signatures of Liver Tissues from Aged Rats following Eight Weeks of Medium-Intensity Exercise. OXIDATIVE MEDICINE AND CELLULAR LONGEVITY 2016; 2016:3269405. [PMID: 28116034 PMCID: PMC5223045 DOI: 10.1155/2016/3269405] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/04/2016] [Revised: 09/05/2016] [Accepted: 11/28/2016] [Indexed: 02/07/2023]
Abstract
Physical activity has emerged as a powerful intervention that promotes healthy aging by maintaining the functional capacity of critical organ systems. Here, by combining functional and proteomics analyses, we examined how hepatic phenotypes might respond to exercise treatment in aged rats. 16 male aged (20 months old) SD rats were divided into exercise and parallel control groups at random; the exercise group had 8 weeks of treadmill training with medium intensity. Whole protein samples of the liver were extracted from both groups and separated by two-dimensional gel electrophoresis. Alternatively objective protein spots with >2-fold difference in expression were selected for enzymological extraction and MS/MS identification. Results show increased activity of the manganese superoxide dismutase and elevated glutathione levels in the livers of exercise-treated animals, but malondialdehyde contents obviously decreased in the liver of the exercise group. Proteomics-based identification of differentially expressed proteins provided an integrated view of the metabolic adaptations occurring in the liver proteome during exercise, which significantly altered the expression of several proteins involved in key liver metabolic pathways including mitochondrial sulfur, glycolysis, methionine, and protein metabolism. These findings indicate that exercise may be beneficial to aged rats through modulation of hepatic protein expression profiles.
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17
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The increasing diversity of functions attributed to the SAFB family of RNA-/DNA-binding proteins. Biochem J 2016; 473:4271-4288. [DOI: 10.1042/bcj20160649] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/04/2016] [Revised: 08/28/2016] [Accepted: 09/02/2016] [Indexed: 12/15/2022]
Abstract
RNA-binding proteins play a central role in cellular metabolism by orchestrating the complex interactions of coding, structural and regulatory RNA species. The SAFB (scaffold attachment factor B) proteins (SAFB1, SAFB2 and SAFB-like transcriptional modulator, SLTM), which are highly conserved evolutionarily, were first identified on the basis of their ability to bind scaffold attachment region DNA elements, but attention has subsequently shifted to their RNA-binding and protein–protein interactions. Initial studies identified the involvement of these proteins in the cellular stress response and other aspects of gene regulation. More recently, the multifunctional capabilities of SAFB proteins have shown that they play crucial roles in DNA repair, processing of mRNA and regulatory RNA, as well as in interaction with chromatin-modifying complexes. With the advent of new techniques for identifying RNA-binding sites, enumeration of individual RNA targets has now begun. This review aims to summarise what is currently known about the functions of SAFB proteins.
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18
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Yamaguchi A, Takanashi K. FUS interacts with nuclear matrix-associated protein SAFB1 as well as Matrin3 to regulate splicing and ligand-mediated transcription. Sci Rep 2016; 6:35195. [PMID: 27731383 PMCID: PMC5059712 DOI: 10.1038/srep35195] [Citation(s) in RCA: 53] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2016] [Accepted: 09/26/2016] [Indexed: 11/23/2022] Open
Abstract
FUS (Fused-in-Sarcoma) is a multifunctional DNA/RNA binding protein linked to familial amyotrophic lateral sclerosis/frontotemporal dementia (ALS/FTD). Since FUS is localized mainly in the nucleus with nucleo-cytoplasmic shuttling, it is critical to understand physiological functions in the nucleus to clarify pathogenesis. Here we report a yeast two-hybrid screening identified FUS interaction with nuclear matrix-associated protein SAFB1 (scaffold attachment factor B1). FUS and SAFB1, abundant in chromatin-bound fraction, interact in a DNA-dependent manner. N-terminal SAP domain of SAFB1, a DNA-binding motif, was required for its localization to chromatin-bound fraction and splicing regulation. In addition, depletion of SAFB1 reduced FUS’s localization to chromatin-bound fraction and splicing activity, suggesting SAFB1 could tether FUS to chromatin compartment thorough N-terminal DNA-binding motif. FUS and SAFB1 also interact with Androgen Receptor (AR) regulating ligand-dependent transcription. Moreover, FUS interacts with another nuclear matrix-associated protein Matrin3, which is muted in a subset of familial ALS cases and reportedly interacts with TDP-43. Interestingly, ectopic ALS-linked FUS mutant sequestered endogenous Matrin3 and SAFB1 in the cytoplasmic aggregates. These findings indicate SAFB1 could be a FUS’s functional platform in chromatin compartment to regulate RNA splicing and ligand-dependent transcription and shed light on the etiological significance of nuclear matrix-associated proteins in ALS pathogenesis.
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Affiliation(s)
- Atsushi Yamaguchi
- Department of Neurobiology, Graduate School of Medicine, Chiba University, Chiba, Japan
| | - Keisuke Takanashi
- Department of Neurobiology, Graduate School of Medicine, Chiba University, Chiba, Japan
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19
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Rivers C, Idris J, Scott H, Rogers M, Lee YB, Gaunt J, Phylactou L, Curk T, Campbell C, Ule J, Norman M, Uney JB. iCLIP identifies novel roles for SAFB1 in regulating RNA processing and neuronal function. BMC Biol 2015; 13:111. [PMID: 26694817 PMCID: PMC4689037 DOI: 10.1186/s12915-015-0220-7] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2015] [Accepted: 12/10/2015] [Indexed: 01/07/2023] Open
Abstract
Background SAFB1 is a RNA binding protein implicated in the regulation of multiple cellular processes such as the regulation of transcription, stress response, DNA repair and RNA processing. To gain further insight into SAFB1 function we used iCLIP and mapped its interaction with RNA on a genome wide level. Results iCLIP analysis found SAFB1 binding was enriched, specifically in exons, ncRNAs, 3’ and 5’ untranslated regions. SAFB1 was found to recognise a purine-rich GAAGA motif with the highest frequency and it is therefore likely to bind core AGA, GAA, or AAG motifs. Confirmatory RT-PCR experiments showed that the expression of coding and non-coding genes with SAFB1 cross-link sites was altered by SAFB1 knockdown. For example, we found that the isoform-specific expression of neural cell adhesion molecule (NCAM1) and ASTN2 was influenced by SAFB1 and that the processing of miR-19a from the miR-17-92 cluster was regulated by SAFB1. These data suggest SAFB1 may influence alternative splicing and, using an NCAM1 minigene, we showed that SAFB1 knockdown altered the expression of two of the three NCAM1 alternative spliced isoforms. However, when the AGA, GAA, and AAG motifs were mutated, SAFB1 knockdown no longer mediated a decrease in the NCAM1 9–10 alternative spliced form. To further investigate the association of SAFB1 with splicing we used exon array analysis and found SAFB1 knockdown mediated the statistically significant up- and downregulation of alternative exons. Further analysis using RNAmotifs to investigate the frequency of association between the motif pairs (AGA followed by AGA, GAA or AAG) and alternative spliced exons found there was a highly significant correlation with downregulated exons. Together, our data suggest SAFB1 will play an important physiological role in the central nervous system regulating synaptic function. We found that SAFB1 regulates dendritic spine density in hippocampal neurons and hence provide empirical evidence supporting this conclusion. Conclusions iCLIP showed that SAFB1 has previously uncharacterised specific RNA binding properties that help coordinate the isoform-specific expression of coding and non-coding genes. These genes regulate splicing, axonal and synaptic function, and are associated with neuropsychiatric disease, suggesting that SAFB1 is an important regulator of key neuronal processes. Electronic supplementary material The online version of this article (doi:10.1186/s12915-015-0220-7) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Caroline Rivers
- Regenerative Medicine Laboratories, School of Clinical Sciences, Cellular & Molecular Medicine, Medical Sciences Building, University Walk, University of Bristol, Bristol, BS8 1TD, UK.
| | - Jalilah Idris
- Regenerative Medicine Laboratories, School of Clinical Sciences, Cellular & Molecular Medicine, Medical Sciences Building, University Walk, University of Bristol, Bristol, BS8 1TD, UK. .,Institute of Medical Sciences & Technology, University of Kuala Lumpur, Kuala Lumpur, 43000, Malaysia.
| | - Helen Scott
- Regenerative Medicine Laboratories, School of Clinical Sciences, Cellular & Molecular Medicine, Medical Sciences Building, University Walk, University of Bristol, Bristol, BS8 1TD, UK.
| | - Mark Rogers
- Intelligent Systems Laboratory, Department of Engineering & Mathematics, Merchant Venturers Building, University of Bristol, Bristol, BS8 1UB, UK.
| | - Youn-Bok Lee
- MRC Centre for Neurodegeneration Research, King's College London, Institute of Psychiatry, London, UK.
| | - Jessica Gaunt
- Regenerative Medicine Laboratories, School of Clinical Sciences, Cellular & Molecular Medicine, Medical Sciences Building, University Walk, University of Bristol, Bristol, BS8 1TD, UK.
| | - Leonidas Phylactou
- Faculty of Computer and Information Science, University of Ljubljana, Trzaska cesta 25, SI-1001, Ljubljana, Slovenia.
| | - Tomaz Curk
- The Cyprus Institute of Neurology & Genetics, PO Box 23462, 1683, Nicosia, Cyprus.
| | - Colin Campbell
- Institute of Medical Sciences & Technology, University of Kuala Lumpur, Kuala Lumpur, 43000, Malaysia.
| | - Jernej Ule
- Department of Molecular Neuroscience, UCL Institute of Neurology, Queen Square, London, WC1N 3BG, UK.
| | - Michael Norman
- Regenerative Medicine Laboratories, School of Clinical Sciences, Cellular & Molecular Medicine, Medical Sciences Building, University Walk, University of Bristol, Bristol, BS8 1TD, UK.
| | - James B Uney
- Regenerative Medicine Laboratories, School of Clinical Sciences, Cellular & Molecular Medicine, Medical Sciences Building, University Walk, University of Bristol, Bristol, BS8 1TD, UK.
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20
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Jiang S, Katz TA, Garee JP, DeMayo FJ, Lee AV, Oesterreich S. Scaffold attachment factor B2 (SAFB2)-null mice reveal non-redundant functions of SAFB2 compared with its paralog, SAFB1. Dis Model Mech 2015; 8:1121-7. [PMID: 26092125 PMCID: PMC4582101 DOI: 10.1242/dmm.019885] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2015] [Accepted: 06/09/2015] [Indexed: 01/03/2023] Open
Abstract
Scaffold attachment factors SAFB1 and SAFB2 are multifunctional proteins that share >70% sequence similarity. SAFB1-knockout (SAFB1(-/-)) mice display a high degree of lethality, severe growth retardation, and infertility in male mice. To assess the in vivo role of SAFB2, and to identify unique functions of the two paralogs, we generated SAFB2(-/-) mice. In stark contrast to SAFB1(-/-), SAFB2(-/-) offspring were born at expected Mendelian ratios and did not show any obvious defects in growth or fertility. Generation of paralog-specific antibodies allowed extensive expression analysis of SAFB1 and SAFB2 in mouse tissues, showing high expression of both SAFB1 and SAFB2 in the immune system, and in hormonally controlled tissues, with especially high expression of SAFB2 in the male reproductive tract. Further analysis showed a significantly increased testis weight in SAFB2(-/-) mice, which was associated with an increased number of Sertoli cells. Our data suggest that this is at least in part caused by alterations in androgen-receptor function and expression upon deletion of SAFB2. Thus, despite a high degree of sequence similarity, SAFB1(-/-) and SAFB2(-/-) mice do not totally phenocopy each other. SAFB2(-/-) mice are viable, and do not show any major defects, and our data suggest a role for SAFB2 in the differentiation and activity of Sertoli cells that deserves further study.
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Affiliation(s)
- Shiming Jiang
- Department of Molecular and Cellular Biology, Baylor College of Medicine, One Baylor Plaza, Houston, TX 77030, USA Lester and Sue Smith Breast Center, Baylor College of Medicine, One Baylor Plaza, Houston, TX 77030, USA
| | - Tiffany A Katz
- Department of Molecular and Cellular Biology, Baylor College of Medicine, One Baylor Plaza, Houston, TX 77030, USA Lester and Sue Smith Breast Center, Baylor College of Medicine, One Baylor Plaza, Houston, TX 77030, USA
| | - Jason P Garee
- Department of Molecular and Cellular Biology, Baylor College of Medicine, One Baylor Plaza, Houston, TX 77030, USA Lester and Sue Smith Breast Center, Baylor College of Medicine, One Baylor Plaza, Houston, TX 77030, USA
| | - Francesco J DeMayo
- Department of Molecular and Cellular Biology, Baylor College of Medicine, One Baylor Plaza, Houston, TX 77030, USA
| | - Adrian V Lee
- Department of Molecular and Cellular Biology, Baylor College of Medicine, One Baylor Plaza, Houston, TX 77030, USA Lester and Sue Smith Breast Center, Baylor College of Medicine, One Baylor Plaza, Houston, TX 77030, USA
| | - Steffi Oesterreich
- Department of Molecular and Cellular Biology, Baylor College of Medicine, One Baylor Plaza, Houston, TX 77030, USA Lester and Sue Smith Breast Center, Baylor College of Medicine, One Baylor Plaza, Houston, TX 77030, USA
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21
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Altmeyer M, Toledo L, Gudjonsson T, Grøfte M, Rask MB, Lukas C, Akimov V, Blagoev B, Bartek J, Lukas J. The chromatin scaffold protein SAFB1 renders chromatin permissive for DNA damage signaling. Mol Cell 2013; 52:206-20. [PMID: 24055346 DOI: 10.1016/j.molcel.2013.08.025] [Citation(s) in RCA: 47] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2013] [Revised: 07/08/2013] [Accepted: 08/14/2013] [Indexed: 01/25/2023]
Abstract
Although the general relevance of chromatin modifications for genotoxic stress signaling, cell-cycle checkpoint activation, and DNA repair is well established, how these modifications reach initial thresholds in order to trigger robust responses remains largely unexplored. Here, we identify the chromatin-associated scaffold attachment factor SAFB1 as a component of the DNA damage response and show that SAFB1 cooperates with histone acetylation to allow for efficient γH2AX spreading and genotoxic stress signaling. SAFB1 undergoes a highly dynamic exchange at damaged chromatin in a poly(ADP-ribose)-polymerase 1- and poly(ADP-ribose)-dependent manner and is required for unperturbed cell-cycle checkpoint activation and guarding cells against replicative stress. Altogether, our data reveal that transient recruitment of an architectural chromatin component is required in order to overcome physiological barriers by making chromatin permissive for DNA damage signaling, whereas the ensuing exclusion of SAFB1 may help prevent excessive signaling.
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Affiliation(s)
- Matthias Altmeyer
- Chromosome Stability and Dynamics Group, Department of Disease Biology, the Novo Nordisk Foundation Center for Protein Research, University of Copenhagen, Blegdamsvej 3B, 2200 Copenhagen, Denmark
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Scaffold attachment factor B1 regulates the androgen receptor in concert with the growth inhibitory kinase MST1 and the methyltransferase EZH2. Oncogene 2013; 33:3235-45. [PMID: 23893242 DOI: 10.1038/onc.2013.294] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2013] [Revised: 04/12/2013] [Accepted: 05/07/2013] [Indexed: 12/16/2022]
Abstract
The androgen receptor (AR) is a transcription factor that employs many diverse interactions with coregulatory proteins in normal physiology and in prostate cancer (PCa). The AR mediates cellular responses in association with chromatin complexes and kinase cascades. Here we report that the nuclear matrix protein, scaffold attachment factor B1 (SAFB1), regulates AR activity and AR levels in a manner that suggests its involvement in PCa. SAFB1 mRNA expression was lower in PCa in comparison with normal prostate tissue in a majority of publicly available RNA expression data sets. SAFB1 protein levels were also reduced with disease progression in a cohort of human PCa that included metastatic tumors. SAFB1 bound to AR and was phosphorylated by the MST1 (Hippo homolog) serine-threonine kinase, previously shown to be an AR repressor, and MST1 localization to AR-dependent promoters was inhibited by SAFB1 depletion. Knockdown of SAFB1 in androgen-dependent LNCaP PCa cells increased AR and prostate-specific antigen (PSA) levels, stimulated growth of cultured cells and subcutaneous xenografts and promoted a more aggressive phenotype, consistent with a repressive AR regulatory function. SAFB1 formed a complex with the histone methyltransferase EZH2 at AR-interacting chromatin sites in association with other polycomb repressive complex 2 (PRC2) proteins. We conclude that SAFB1 acts as a novel AR co-regulator at gene loci where signals from the MST1/Hippo and EZH2 pathways converge.
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Hernández-Hernández JM, Mallappa C, Nasipak BT, Oesterreich S, Imbalzano AN. The Scaffold attachment factor b1 (Safb1) regulates myogenic differentiation by facilitating the transition of myogenic gene chromatin from a repressed to an activated state. Nucleic Acids Res 2013; 41:5704-16. [PMID: 23609547 PMCID: PMC3675494 DOI: 10.1093/nar/gkt285] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023] Open
Abstract
The regulation of skeletal muscle gene expression during myogenesis is mediated by lineage-specific transcription factors in combination with numerous cofactors, many of which modify chromatin structure. However, the involvement of scaffolding proteins that organize chromatin and chromatin-associated regulatory proteins has not extensively been explored in myogenic differentiation. Here, we report that Scaffold attachment factor b1 (Safb1), primarily associated with transcriptional repression, functions as a positive regulator of myogenic differentiation. Knockdown of Safb1 inhibited skeletal muscle marker gene expression and differentiation in cultured C2C12 myoblasts. In contrast, over-expression resulted in the premature expression of critical muscle structural proteins and formation of enlarged thickened myotubes. Safb1 co-immunoprecipitated with MyoD and was co-localized on myogenic promoters. Upon Safb1 knockdown, the repressive H3K27me3 histone mark and binding of the Polycomb histone methyltransferase Ezh2 persisted at differentiation-dependent gene promoters. In contrast, the appearance of histone marks and regulators associated with myogenic gene activation, such as myogenin and the SWI/SNF chromatin remodelling enzyme ATPase, Brg1, was blocked. These results indicate that the scaffold protein Safb1 contributes to the activation of skeletal muscle gene expression during myogenic differentiation by facilitating the transition of promoter sequences from a repressive chromatin structure to one that is transcriptionally permissive.
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Affiliation(s)
- J. Manuel Hernández-Hernández
- Department of Cell and Developmental Biology, University of Massachusetts Medical School, 55 Lake Avenue North, Worcester, MA 01655, USA and Department of Pharmacology and Chemical Biology, Women’s Cancer Research Center, Magee-Womens Research Institute, University of Pittsburgh Cancer Institute, 204 Craft Avenue, Pittsburgh, PA 15213, USA
| | - Chandrashekara Mallappa
- Department of Cell and Developmental Biology, University of Massachusetts Medical School, 55 Lake Avenue North, Worcester, MA 01655, USA and Department of Pharmacology and Chemical Biology, Women’s Cancer Research Center, Magee-Womens Research Institute, University of Pittsburgh Cancer Institute, 204 Craft Avenue, Pittsburgh, PA 15213, USA
| | - Brian T. Nasipak
- Department of Cell and Developmental Biology, University of Massachusetts Medical School, 55 Lake Avenue North, Worcester, MA 01655, USA and Department of Pharmacology and Chemical Biology, Women’s Cancer Research Center, Magee-Womens Research Institute, University of Pittsburgh Cancer Institute, 204 Craft Avenue, Pittsburgh, PA 15213, USA
| | - Steffi Oesterreich
- Department of Cell and Developmental Biology, University of Massachusetts Medical School, 55 Lake Avenue North, Worcester, MA 01655, USA and Department of Pharmacology and Chemical Biology, Women’s Cancer Research Center, Magee-Womens Research Institute, University of Pittsburgh Cancer Institute, 204 Craft Avenue, Pittsburgh, PA 15213, USA
| | - Anthony N. Imbalzano
- Department of Cell and Developmental Biology, University of Massachusetts Medical School, 55 Lake Avenue North, Worcester, MA 01655, USA and Department of Pharmacology and Chemical Biology, Women’s Cancer Research Center, Magee-Womens Research Institute, University of Pittsburgh Cancer Institute, 204 Craft Avenue, Pittsburgh, PA 15213, USA
- *To whom correspondence should be addressed. Tel: +1 508 856 1029; Fax: +1 508 856 5612;
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Hashimoto T, Matsuda KI, Kawata M. Scaffold attachment factor B (SAFB)1 and SAFB2 cooperatively inhibit the intranuclear mobility and function of ERα. J Cell Biochem 2012; 113:3039-50. [PMID: 22566185 DOI: 10.1002/jcb.24182] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
Estrogen receptor alpha (ERα) plays a key role in physiological and pathophysiological processes as a ligand-activated transcriptional factor that is regulated by cofactors. ERα-mediated transcriptional regulation is closely correlated with the mobility of ERα in the nucleus in association with the nuclear matrix, the framework for nuclear events including transcription. However, the relationship between ERα mobility and the cofactors of ERα is unclear. Scaffold attachment factor B1 (SAFB1) and its paralog SAFB2 are nuclear matrix binding proteins that have been characterized as ERα corepressors. Here, using chimeric fluorescent proteins (FPs), we show that SAFB1 and SAFB2 colocalize with ERα in the nucleus of living cells after 17β-estradiol (E2) treatment. Co-immunoprecipitation (co-IP) experiments indicated that ERα interacts with both SAFB1 and SAFB2 in the presence of E2. Fluorescence recovery after photobleaching analysis revealed that SAFB1 and SAFB2 each decrease ERα mobility, and interestingly, coexpression of SAFB1 and SAFB2 causes a synergistic reduction in ERα dynamics under E2 treatment. In accordance with these mobility changes, ERα-mediated transcription and proliferation are cooperatively inhibited by SAFB1 and SAFB2. These results indicate that SAFB1 and SAFB2 are crucial repressors for ERα dynamics in association with the nuclear matrix and that their synergistic regulation of ERα mobility is sufficient for inhibiting ERα function.
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Affiliation(s)
- Takashi Hashimoto
- Department of Anatomy and Neurobiology, Kyoto Prefectural University of Medicine, Kawaramachi Hirokoji, Kamigyo-ku, Kyoto 602-8566, Japan
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25
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Mokhonov VV, Theendakara VP, Gribanova YE, Ahmedli NB, Farber DB. Sequence-specific binding of recombinant Zbed4 to DNA: insights into Zbed4 participation in gene transcription and its association with other proteins. PLoS One 2012; 7:e35317. [PMID: 22693546 PMCID: PMC3365051 DOI: 10.1371/journal.pone.0035317] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2012] [Accepted: 03/15/2012] [Indexed: 11/19/2022] Open
Abstract
Zbed4, a member of the BED subclass of Zinc-finger proteins, is expressed in cone photoreceptors and glial Müller cells of human retina whereas it is only present in Müller cells of mouse retina. To characterize structural and functional properties of Zbed4, enough amounts of purified protein were needed. Thus, recombinant Zbed4 was expressed in E. coli and its refolding conditions optimized for the production of homogenous and functionally active protein. Zbed4’s secondary structure, determined by circular dichroism spectroscopy, showed that this protein contains 32% α-helices, 18% β-sheets, 20% turns and 30% unordered structures. CASTing was used to identify the target sites of Zbed4 in DNA. The majority of the DNA fragments obtained contained poly-Gs and some of them had, in addition, the core signature of GC boxes; a few clones had only GC-boxes. With electrophoretic mobility shift assays we demonstrated that Zbed4 binds both not only to DNA and but also to RNA oligonucleotides with very high affinity, interacting with poly-G tracts that have a minimum of 5 Gs; its binding to and GC-box consensus sequences. However, the latter binding depends on the GC-box flanking nucleotides. We also found that Zbed4 interacts in Y79 retinoblastoma cells with nuclear and cytoplasmic proteins Scaffold Attachment Factor B1 (SAFB1), estrogen receptor alpha (ERα), and cellular myosin 9 (MYH9), as shown with immunoprecipitation and mass spectrometry studies as well as gel overlay assays. In addition, immunostaining corroborated the co-localization of Zbed4 with these proteins. Most importantly, in vitro experiments using constructs containing promoters of genes directing expression of the luciferase gene, showed that Zbed4 transactivates the transcription of those promoters with poly-G tracts.
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Affiliation(s)
- Vladislav V. Mokhonov
- Jules Stein Eye Institute and Department of Ophthalmology, David Geffen School of Medicine, University of California Los Angeles, Los Angeles, California, United States of America
| | - Veena P. Theendakara
- Jules Stein Eye Institute and Department of Ophthalmology, David Geffen School of Medicine, University of California Los Angeles, Los Angeles, California, United States of America
| | - Yekaterina E. Gribanova
- Jules Stein Eye Institute and Department of Ophthalmology, David Geffen School of Medicine, University of California Los Angeles, Los Angeles, California, United States of America
| | - Novruz B. Ahmedli
- Jules Stein Eye Institute and Department of Ophthalmology, David Geffen School of Medicine, University of California Los Angeles, Los Angeles, California, United States of America
- * E-mail: (DBF); (NBA)
| | - Debora B. Farber
- Jules Stein Eye Institute and Department of Ophthalmology, David Geffen School of Medicine, University of California Los Angeles, Los Angeles, California, United States of America
- Molecular Biology Institute, University of California Los Angeles, Los Angeles, California, United States of America
- Brain Research Institute, University of California Los Angeles, Los Angeles, California, United States of America
- * E-mail: (DBF); (NBA)
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26
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Tang CS, Ferreira MAR. A gene-based test of association using canonical correlation analysis. ACTA ACUST UNITED AC 2012; 28:845-50. [PMID: 22296789 DOI: 10.1093/bioinformatics/bts051] [Citation(s) in RCA: 50] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
MOTIVATION Canonical correlation analysis (CCA) measures the association between two sets of multidimensional variables. We reasoned that CCA could provide an efficient and powerful approach for both univariate and multivariate gene-based tests of association without the need for permutation testing. RESULTS Compared with a commonly used permutation-based approach, CCA (i) is faster; (ii) has appropriate type-I error rate for normally distributed quantitative traits; (iii) provides comparable power for small to medium-sized genes (<100 kb); (iv) provides greater power when the causal variants are uncommon; (v) provides considerably less power for larger genes (≥100 kb) when the causal variants have a broad minor allele frequency (MAF) spectrum. Application to a GWAS of leukocyte levels identified SAFB and a histone gene cluster as novel putative loci harboring multiple independent variants regulating lymphocyte and neutrophil counts.
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Affiliation(s)
- Clara S Tang
- Queensland Institute of Medical Research, Brisbane, QLD 4029, Australia
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27
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Lachapelle S, Oesterreich S, Lebel M. The Werner syndrome helicase protein is required for cell proliferation, immortalization, and tumorigenesis in Scaffold attachment factor B1 deficient mice. Aging (Albany NY) 2011; 3:277-90. [PMID: 21464516 PMCID: PMC3091521 DOI: 10.18632/aging.100300] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
Werner syndrome (WS) is a rare disorder characterized by the premature onset of several pathologies associated with aging. The gene responsible for WS codes for a RecQ-type DNA helicase and is believed to be involved in different aspects of DNA repair, replication, and transcription. We recently identified the Scaffold attachment factor B1 (SAFB1) as a potential interactants in human cells. SAFB1 is a multifunctional protein that binds both nucleic acids and is involved in the attachment of chromatin to the nuclear matrix, transcription, and stress response. Mice lacking SAFB1 exhibit developmental abnormalities in their lungs, high incidence of perinatal lethality, and adults develop different types of tumors. Mouse embryonic fibroblasts from Safb1-null animals are immortalized in culture. In this study, mice with a mutation in the helicase domain of the Wrn gene were crossed to Safb1-null mice. Double homozygous mutant mice exhibited increased apoptosis, a lower cell proliferation rate in their lungs and a higher incidence of perinatal death compared to Safb1-null mice. Few double homozygous mutants survived weaning and died before the age of six months. Finally, mouse embryonic fibroblasts lacking a functional Wrn helicase inhibited the immortalization of Safb1-null cells. These results indicate that an intact Wrn protein is required for immortalization and tumorigenesis in Safb1-null mice.
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Affiliation(s)
- Sophie Lachapelle
- Centre de Recherche en Cancérologie de l'Université Laval, Hôpital Hôtel‐Dieu de Québec, Québec City, Canada
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28
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Garee JP, Meyer R, Oesterreich S. Co-repressor activity of scaffold attachment factor B1 requires sumoylation. Biochem Biophys Res Commun 2011; 408:516-22. [PMID: 21527249 DOI: 10.1016/j.bbrc.2011.04.040] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2011] [Accepted: 04/08/2011] [Indexed: 01/14/2023]
Abstract
Sumoylation is an emerging modification associated with a variety of cellular processes including the regulation of transcriptional activities of nuclear receptors and their coregulators. As SUMO modifications are often associated with transcriptional repression, we examined if sumoylation was involved in modulation of the transcriptional repressive activity of scaffold attachment factor B1. Here we show that SAFB1 is modified by both the SUMO1 and SUMO2/3 family of proteins, on lysine's K231 and K294. Further, we demonstrate that SAFB1 can interact with PIAS1, a SUMO E3 ligase which mediates SAFB1 sumoylation. Additionally, SENP1 was identified as the enzyme desumoylating SAFB1. Mutation of the SAFB1 sumoylation sites lead to a loss of transcriptional repression, at least in part due to decreased interaction with HDAC3, a known transcriptional repressor and SAFB1 binding partner. In summary, the transcriptional repressor SAFB1 is modified by both SUMO1 and SUMO2/3, and this modification is necessary for its full repressive activity.
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Affiliation(s)
- Jason P Garee
- Breast Center and Department of Molecular and Cellular Biology, Baylor College of Medicine, Houston, TX, USA
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29
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Easwaran HP, Baylin SB. Role of nuclear architecture in epigenetic alterations in cancer. COLD SPRING HARBOR SYMPOSIA ON QUANTITATIVE BIOLOGY 2011; 75:507-15. [PMID: 21447817 DOI: 10.1101/sqb.2010.75.031] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
It is widely accepted that cancer results from an array of epigenetic and genetic alterations, particularly aberrant epigenetic patterns that are a hallmark of every cancer type studied. Another well-known feature of cancer cells is the array of abnormalities in their nuclear structure. Although it is known that nuclear structure has an important role in the regulation of gene expression, we know little about the direct relationship between nuclear structural alterations and aberrant epigenetic patterns in cancer. Here, we discuss some of the recent studies from our lab and others to understand the relationship between alterations of nuclear architecture and aberrant epigenetic patterns in cancer cells. Although the precise relationship remains elusive, we suggest that changes in nuclear structure and composition could alter long-range genomic interactions and cause global epigenetic changes during tumorigenesis. We emphasize the need for further studies to elucidate the direct relationship between nuclear structure alterations and aberrant epigenetic patterns in cancers.
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Affiliation(s)
- H P Easwaran
- The Sidney Kimmel Cancer Research Center at Johns Hopkins University, Bunting Blaustein Cancer Research Building, Baltimore, Maryland 21231-1000, USA
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30
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Peidis P, Voukkalis N, Aggelidou E, Georgatsou E, Hadzopoulou-Cladaras M, Scott RE, Nikolakaki E, Giannakouros T. SAFB1 interacts with and suppresses the transcriptional activity of p53. FEBS Lett 2010; 585:78-84. [DOI: 10.1016/j.febslet.2010.11.054] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2010] [Revised: 11/23/2010] [Accepted: 11/24/2010] [Indexed: 01/04/2023]
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Fuentealba RA, Udan M, Bell S, Wegorzewska I, Shao J, Diamond MI, Weihl CC, Baloh RH. Interaction with polyglutamine aggregates reveals a Q/N-rich domain in TDP-43. J Biol Chem 2010; 285:26304-14. [PMID: 20554523 DOI: 10.1074/jbc.m110.125039] [Citation(s) in RCA: 126] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
The identification of pathologic TDP-43 aggregates in amyotrophic lateral sclerosis (ALS) and frontotemporal lobar degeneration, followed by the discovery of dominantly inherited point mutations in TDP-43 in familial ALS, have been critical insights into the mechanism of these untreatable neurodegenerative diseases. However, the biochemical basis of TDP-43 aggregation and the mechanism of how mutations in TDP-43 lead to disease remain enigmatic. In efforts to understand how TDP-43 alters its cellular localization in response to proteotoxic stress, we found that TDP-43 is sequestered into polyglutamine aggregates. Furthermore, we found that binding to polyglutamine aggregates requires a previously uncharacterized glutamine/asparagine (Q/N)-rich region in the C-terminal domain of TDP-43. Sequestration into polyglutamine aggregates causes TDP-43 to be cleared from the nucleus and become detergent-insoluble. Finally, we observed that sequestration into polyglutamine aggregates led to loss of TDP-43-mediated splicing in the nucleus and that polyglutamine toxicity could be partially rescued by increasing expression of TDP-43. These data indicate pathologic sequestration into polyglutamine aggregates, and loss of nuclear TDP-43 function may play an unexpected role in polyglutamine disease pathogenesis. Furthermore, as Q/N domains have a strong tendency to self-aggregate and in some cases can function as prions, the identification of a Q/N domain in TDP-43 has important implications for the mechanism of pathologic aggregation of TDP-43 in ALS and other neurodegenerative diseases.
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Affiliation(s)
- Rodrigo A Fuentealba
- Department of Neurology, Washington University School of Medicine, St. Louis, Missouri 63110, USA
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Tsuchiya M, Parker JS, Kono H, Matsuda M, Fujii H, Rusyn I. Gene expression in nontumoral liver tissue and recurrence-free survival in hepatitis C virus-positive hepatocellular carcinoma. Mol Cancer 2010; 9:74. [PMID: 20380719 PMCID: PMC2856554 DOI: 10.1186/1476-4598-9-74] [Citation(s) in RCA: 63] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2010] [Accepted: 04/09/2010] [Indexed: 02/08/2023] Open
Abstract
Background The goal of this study was to understand gene expression signatures of hepatocellular carcinoma (HCC) recurrence in subjects with hepatitis C virus (HCV) infection. Recurrence-free survival (RFS) following curative resection of HCC in subjects with HCV is highly variable. Traditional clinico-pathological endpoints are recognized as weak predictors of RFS. It has been suggested that gene expression profiling of HCC and nontumoral liver tissue may improve prediction of RFS, aid in understanding of the underlying liver disease, and guide individualized patient management. Frozen samples of the tumors and nontumoral liver were obtained from 47 subjects with HCV-associated HCC. Additional nontumoral liver samples were obtained from HCV-free subjects with metastatic liver tumors. Gene expression profiling data was used to determine the molecular signature of HCV-associated HCC and to develop a predictor of RFS. Results The molecular profile of the HCV-associated HCC confirmed central roles for MYC and TGFβ1 in liver tumor development. Gene expression in tumors was found to have poor predictive power with regards to RFS, but analysis of nontumoral tissues yielded a strong predictor for RFS in late-recurring (>1 year) subjects. Importantly, nontumoral tissue-derived gene expression predictor of RFS was highly significant in both univariable and multivariable Cox proportional hazard model analyses. Conclusions Microarray analysis of the nontumoral tissues from subjects with HCV-associated HCC delivers novel molecular signatures of RFS, especially among the late-recurrence subjects. The gene expression predictor may hold important insights into the pathobiology of HCC recurrence and de novo tumor formation in cirrhotic patients.
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Affiliation(s)
- Masato Tsuchiya
- Department of Environmental Sciences and Engineering, Gillings School of Global Public Health, University of North Carolina, Chapel Hill, NC, USA
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