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Melnikova L, Golovnin A. Multiple Roles of dXNP and dADD1- Drosophila Orthologs of ATRX Chromatin Remodeler. Int J Mol Sci 2023; 24:16486. [PMID: 38003676 PMCID: PMC10671109 DOI: 10.3390/ijms242216486] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2023] [Revised: 11/11/2023] [Accepted: 11/16/2023] [Indexed: 11/26/2023] Open
Abstract
The Drosophila melanogaster dADD1 and dXNP proteins are orthologues of the ADD and SNF2 domains of the vertebrate ATRX (Alpha-Thalassemia with mental Retardation X-related) protein. ATRX plays a role in general molecular processes, such as regulating chromatin status and gene expression, while dADD1 and dXNP have similar functions in the Drosophila genome. Both ATRX and dADD1/dXNP interact with various protein partners and participate in various regulatory complexes. Disruption of ATRX expression in humans leads to the development of α-thalassemia and cancer, especially glioma. However, the mechanisms that allow ATRX to regulate various cellular processes are poorly understood. Studying the functioning of dADD1/dXNP in the Drosophila model may contribute to understanding the mechanisms underlying the multifunctional action of ATRX and its connection with various cellular processes. This review provides a brief overview of the currently available information in mammals and Drosophila regarding the roles of ATRX, dXNP, and dADD1. It discusses possible mechanisms of action of complexes involving these proteins.
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Affiliation(s)
- Larisa Melnikova
- Department of Drosophila Molecular Genetics, Institute of Gene Biology, Russian Academy of Sciences, 34/5 Vavilov St., 119334 Moscow, Russia
| | - Anton Golovnin
- Department of Drosophila Molecular Genetics, Institute of Gene Biology, Russian Academy of Sciences, 34/5 Vavilov St., 119334 Moscow, Russia
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Sachs P, Bergmaier P, Treutwein K, Mermoud JE. The Conserved Chromatin Remodeler SMARCAD1 Interacts with TFIIIC and Architectural Proteins in Human and Mouse. Genes (Basel) 2023; 14:1793. [PMID: 37761933 PMCID: PMC10530723 DOI: 10.3390/genes14091793] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2023] [Revised: 09/08/2023] [Accepted: 09/08/2023] [Indexed: 09/29/2023] Open
Abstract
In vertebrates, SMARCAD1 participates in transcriptional regulation, heterochromatin maintenance, DNA repair, and replication. The molecular basis underlying its involvement in these processes is not well understood. We identified the RNA polymerase III general transcription factor TFIIIC as an interaction partner of native SMARCAD1 in mouse and human models using endogenous co-immunoprecipitations. TFIIIC has dual functionality, acting as a general transcription factor and as a genome organizer separating chromatin domains. We found that its partnership with SMARCAD1 is conserved across different mammalian cell types, from somatic to pluripotent cells. Using purified proteins, we confirmed that their interaction is direct. A gene expression analysis suggested that SMARCAD1 is dispensable for TFIIIC function as an RNA polymerase III transcription factor in mouse ESCs. The distribution of TFIIIC and SMARCAD1 in the ESC genome is distinct, and unlike in yeast, SMARCAD1 is not enriched at active tRNA genes. Further analysis of SMARCAD1-binding partners in pluripotent and differentiated mammalian cells reveals that SMARCAD1 associates with several factors that have key regulatory roles in chromatin organization, such as cohesin, laminB, and DDX5. Together, our work suggests for the first time that the SMARCAD1 enzyme participates in genome organization in mammalian nuclei through interactions with architectural proteins.
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Affiliation(s)
- Parysatis Sachs
- Institute of Molecular Biology and Tumor Research, Philipps University Marburg, 35043 Marburg, Germany
- CMC Development, R&D, Sanofi, 65926 Frankfurt, Germany
| | - Philipp Bergmaier
- Institute of Molecular Biology and Tumor Research, Philipps University Marburg, 35043 Marburg, Germany
- Global Development Operations, R&D, Merck Healthcare, 64293 Darmstadt, Germany
| | - Katrin Treutwein
- Institute of Molecular Biology and Tumor Research, Philipps University Marburg, 35043 Marburg, Germany
| | - Jacqueline E. Mermoud
- Institute of Molecular Biology and Tumor Research, Philipps University Marburg, 35043 Marburg, Germany
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3
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Sabirov M, Popovich A, Boyko K, Nikolaeva A, Kyrchanova O, Maksimenko O, Popov V, Georgiev P, Bonchuk A. Mechanisms of CP190 Interaction with Architectural Proteins in Drosophila Melanogaster. Int J Mol Sci 2021; 22:12400. [PMID: 34830280 DOI: 10.3390/ijms222212400] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2021] [Revised: 11/12/2021] [Accepted: 11/15/2021] [Indexed: 01/08/2023] Open
Abstract
Most of the known Drosophila architectural proteins interact with an important cofactor, CP190, that contains three domains (BTB, M, and D) that are involved in protein–protein interactions. The highly conserved N-terminal CP190 BTB domain forms a stable homodimer that interacts with unstructured regions in the three best-characterized architectural proteins: dCTCF, Su(Hw), and Pita. Here, we identified two new CP190 partners, CG4730 and CG31365, that interact with the BTB domain. The CP190 BTB resembles the previously characterized human BCL6 BTB domain, which uses its hydrophobic groove to specifically associate with unstructured regions of several transcriptional repressors. Using GST pull-down and yeast two-hybrid assays, we demonstrated that mutations in the hydrophobic groove strongly affect the affinity of CP190 BTB for the architectural proteins. In the yeast two-hybrid assay, we found that architectural proteins use various mechanisms to improve the efficiency of interaction with CP190. Pita and Su(Hw) have two unstructured regions that appear to simultaneously interact with hydrophobic grooves in the BTB dimer. In dCTCF and CG31365, two adjacent regions interact simultaneously with the hydrophobic groove of the BTB and the M domain of CP190. Finally, CG4730 interacts with the BTB, M, and D domains of CP190 simultaneously. These results suggest that architectural proteins use different mechanisms to increase the efficiency of interaction with CP190.
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Papayanni PG, Psatha N, Christofi P, Li XG, Melo P, Volpin M, Montini E, Liu M, Kaltsounis G, Yiangou M, Emery DW, Anagnostopoulos A, Papayannopoulou T, Huang S, Stamatoyannopoulos G, Yannaki E. Investigating the Barrier Activity of Novel, Human Enhancer-Blocking Chromatin Insulators for Hematopoietic Stem Cell Gene Therapy. Hum Gene Ther 2021; 32:1186-1199. [PMID: 34477013 DOI: 10.1089/hum.2021.142] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
Despite the unequivocal success of hematopoietic stem and progenitor cell gene therapy, limitations still exist including genotoxicity and variegation/silencing of transgene expression. A class of DNA regulatory elements known as chromatin insulators (CIs) can mitigate both vector transcriptional silencing (barrier CIs) and vector-induced genotoxicity (enhancer-blocking CIs) and have been proposed as genetic modulators to minimize unwanted vector/genome interactions. Recently, a number of human, small-sized, and compact CIs bearing strong enhancer-blocking activity were identified. To ultimately uncover an ideal CI with a dual, enhancer-blocking and barrier activity, we interrogated these elements in vitro and in vivo. After initial screening of a series of these enhancer-blocking insulators for potential barrier activity, we identified three distinct categories with no, partial, or full protection against transgene silencing. Subsequently, the two CIs with full barrier activity (B4 and C1) were tested for their ability to protect against position effects in primary cells, after incorporation into lentiviral vectors (LVs) and transduction of human CD34+ cells. B4 and C1 did not adversely affect vector titers due to their small size, while they performed as strong barrier insulators in CD34+ cells, both in vitro and in vivo, shielding transgene's long-term expression, more robustly when placed in the forward orientation. Overall, the incorporation of these dual-functioning elements into therapeutic viral vectors will potentially provide a new generation of safer and more efficient LVs for all hematopoietic stem cell gene therapy applications.
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Affiliation(s)
- Penelope-Georgia Papayanni
- Hematopoietic Cell Transplantation Unit, Hematology Department, Gene and Cell Therapy Center, "George Papanikolaou" Hospital, Thessaloniki, Greece.,Department of Genetics, Development and Molecular Biology, School of Biology, Aristotle University of Thessaloniki, Thessaloniki, Greece
| | - Nikoletta Psatha
- Altius Institute for Biomedical Sciences, Seattle, Washington, USA
| | - Panayota Christofi
- Hematopoietic Cell Transplantation Unit, Hematology Department, Gene and Cell Therapy Center, "George Papanikolaou" Hospital, Thessaloniki, Greece.,Department of Genetics, Development and Molecular Biology, School of Biology, Aristotle University of Thessaloniki, Thessaloniki, Greece
| | - Xing-Guo Li
- Graduate Institute of Biomedical Sciences, China Medical University, Taichung, Taiwan
| | - Pamela Melo
- Hematopoietic Cell Transplantation Unit, Hematology Department, Gene and Cell Therapy Center, "George Papanikolaou" Hospital, Thessaloniki, Greece.,Department of Genetics, Development and Molecular Biology, School of Biology, Aristotle University of Thessaloniki, Thessaloniki, Greece
| | - Monica Volpin
- San Raffaele Telethon Institute for Gene Therapy-IRCCS Ospedale San Raffaele Scientific Institute, Milan, Italy
| | - Eugenio Montini
- San Raffaele Telethon Institute for Gene Therapy-IRCCS Ospedale San Raffaele Scientific Institute, Milan, Italy
| | - Mingdong Liu
- Department of Medicine, University of Washington, Seattle, Washington, USA
| | - Georgios Kaltsounis
- Hematopoietic Cell Transplantation Unit, Hematology Department, Gene and Cell Therapy Center, "George Papanikolaou" Hospital, Thessaloniki, Greece
| | - Minas Yiangou
- Department of Genetics, Development and Molecular Biology, School of Biology, Aristotle University of Thessaloniki, Thessaloniki, Greece
| | - David W Emery
- Department of Medicine, University of Washington, Seattle, Washington, USA
| | - Achilles Anagnostopoulos
- Hematopoietic Cell Transplantation Unit, Hematology Department, Gene and Cell Therapy Center, "George Papanikolaou" Hospital, Thessaloniki, Greece
| | | | - Suming Huang
- Department of Pediatrics, Pennsylvania State University College of Medicine, Hershey, Pennsylvania, USA
| | | | - Evangelia Yannaki
- Hematopoietic Cell Transplantation Unit, Hematology Department, Gene and Cell Therapy Center, "George Papanikolaou" Hospital, Thessaloniki, Greece.,Department of Medicine, University of Washington, Seattle, Washington, USA
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Khalisova KY, Georgiev PG, Bonchuk AN. Human CTCF Interacts with Drosophila CP190, but not with Kaiso. DOKL BIOCHEM BIOPHYS 2021; 497:112-115. [PMID: 33895926 DOI: 10.1134/s1607672921020071] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2020] [Revised: 01/13/2021] [Accepted: 01/14/2021] [Indexed: 11/23/2022]
Abstract
Human CTCF (hCTCF) is a major architectural protein in mammals. In Drosophila, the CTCF homologue (dCTCF) interacts with the BTB domain of the CP190 protein, which is involved in the establishment of open chromatin and activity of insulators. Previously, it was shown that the BTB protein Kaiso interacts with hCTCF and regulates its activity. We have carried out a detailed study of the interaction between these proteins in the yeast two-hybrid assay. Surprisingly, Kaiso did not interact with hCTCF and its Drosophila homologue. On the other hand, CP190 interacted with the C-terminus of hCTCF. The results obtained demonstrate that the interaction between CTCF and CP190 proteins is highly conserved. It is likely that humans have other BTB proteins that perform the functions described for the Drosophila CP190.
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Affiliation(s)
- K Y Khalisova
- Institute of Gene Biology, Russian Academy of Sciences, Moscow, Russia
| | - P G Georgiev
- Institute of Gene Biology, Russian Academy of Sciences, Moscow, Russia
| | - A N Bonchuk
- Institute of Gene Biology, Russian Academy of Sciences, Moscow, Russia.
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Kyrchanova O, Georgiev P. Mechanisms of Enhancer-Promoter Interactions in Higher Eukaryotes. Int J Mol Sci 2021; 22:ijms22020671. [PMID: 33445415 PMCID: PMC7828040 DOI: 10.3390/ijms22020671] [Citation(s) in RCA: 17] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2020] [Revised: 12/28/2020] [Accepted: 01/09/2021] [Indexed: 12/13/2022] Open
Abstract
In higher eukaryotes, enhancers determine the activation of developmental gene transcription in specific cell types and stages of embryogenesis. Enhancers transform the signals produced by various transcription factors within a given cell, activating the transcription of the targeted genes. Often, developmental genes can be associated with dozens of enhancers, some of which are located at large distances from the promoters that they regulate. Currently, the mechanisms underlying specific distance interactions between enhancers and promoters remain poorly understood. This review briefly describes the properties of enhancers and discusses the mechanisms of distance interactions and potential proteins involved in this process.
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Kyrchanova O, Sabirov M, Mogila V, Kurbidaeva A, Postika N, Maksimenko O, Schedl P, Georgiev P. Complete reconstitution of bypass and blocking functions in a minimal artificial Fab-7 insulator from Drosophila bithorax complex. Proc Natl Acad Sci U S A 2019; 116:13462-7. [PMID: 31209019 DOI: 10.1073/pnas.1907190116] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022] Open
Abstract
Boundaries in the bithorax complex (BX-C) delimit autonomous regulatory domains that drive parasegment-specific expression of the Hox genes Ubx, abd-A, and Abd-B The Fab-7 boundary is located between the iab-6 and iab-7 domains and has two key functions: blocking cross-talk between these domains and at the same time promoting communication (boundary bypass) between iab-6 and the Abd-B promoter. Using a replacement strategy, we found that multimerized binding sites for the architectural proteins Pita, Su(Hw), and dCTCF function as conventional insulators and block cross-talk between the iab-6 and iab-7 domains; however, they lack bypass activity, and iab-6 is unable to regulate Abd-B Here we show that an ∼200-bp sequence of dHS1 from the Fab-7 boundary rescues the bypass defects of these multimerized binding sites. The dHS1 sequence is bound in embryos by a large multiprotein complex, Late Boundary Complex (LBC), that contains the zinc finger proteins CLAMP and GAF. Using deletions and mutations in critical GAGAG motifs, we show that bypass activity correlates with the efficiency of recruitment of LBC components CLAMP and GAF to the artificial boundary. These results indicate that LBC orchestrates long-distance communication between the iab-6 regulatory domain and the Abd-B gene, while the Pita, Su(Hw), and dCTCF proteins function to block local cross-talk between the neighboring regulatory domains iab-6 and iab-7.
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Duan T, Geyer PK. Spermiogenesis and Male Fertility Require the Function of Suppressor of Hairy-Wing in Somatic Cyst Cells of Drosophila. Genetics 2018; 209:757-72. [PMID: 29739818 DOI: 10.1534/genetics.118.301088] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2018] [Accepted: 05/01/2018] [Indexed: 02/07/2023] Open
Abstract
Drosophila Suppressor of Hairy-wing [Su(Hw)] protein is an example of a multivalent transcription factor. Although best known for its role in establishing the chromatin insulator of the gypsy retrotransposon, Su(Hw) functions as an activator and repressor at non-gypsy genomic sites. It remains unclear how the different regulatory activities of Su(Hw) are utilized during development. Motivated from observations of spatially restricted expression of Su(Hw) in the testis, we investigated the role of Su(Hw) in spermatogenesis to advance an understanding of its developmental contributions as an insulator, repressor, and activator protein. We discovered that Su(Hw) is required for sustained male fertility. Although dynamics of Su(Hw) expression coincide with changes in nuclear architecture and activation of coregulated testis-specific gene clusters, we show that loss of Su(Hw) does not disrupt meiotic chromosome pairing or transcription of testis-specific genes, suggesting that Su(Hw) has minor architectural or insulator functions in the testis. Instead, Su(Hw) has a prominent role as a repressor of neuronal genes, consistent with suggestions that Su(Hw) is a functional homolog of mammalian REST, a repressor of neuronal genes in non-neuronal tissues. We show that Su(Hw) regulates transcription in both germline and somatic cells. Surprisingly, the essential spermatogenesis function of Su(Hw) resides in somatic cyst cells, implying context-specific consequences due to loss of this transcription factor. Together, our studies highlight that Su(Hw) has a major developmental function as a transcriptional repressor, with the effect of its loss dependent upon the cell-specific factors.
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Baiamonte E, Spinelli G, Maggio A, Acuto S, Cavalieri V. The Sea Urchin sns5 Chromatin Insulator Shapes the Chromatin Architecture of a Lentivirus Vector Integrated in the Mammalian Genome. Nucleic Acid Ther 2016; 26:318-326. [PMID: 27248156 DOI: 10.1089/nat.2016.0614] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
Lentivirus vectors are presently the favorite vehicles for therapeutic gene transfer in hematopoietic cells. Nonetheless, these vectors integrate randomly throughout the genome, exhibiting variegation of transgene expression due to the spreading of heterochromatin into the vector sequences. Moreover, the cis-regulatory elements harbored by the vector could disturb the proper transcription of resident genes neighboring the integration site. The incorporation of chromatin insulators in flanking position to the transferred unit can alleviate both the above-mentioned dangerous effects, due to the insulator-specific barrier and enhancer-blocking activities. In this study, we report the valuable properties of the sea urchin-derived sns5 insulator in improving the expression efficiency of a lentivirus vector integrated in the mammalian erythroid genome. We show that these results neither reflect an intrinsic sns5 enhancer activity nor rely on the recruitment of the erythroid-specific GATA-1 factor to sns5. Furthermore, by using the Chromosome Conformation Capture technology, we report that a single copy of the sns5-insulated vector is specifically organized into an independent chromatin loop at the provirus locus. Our results not only provide new clues concerning the molecular mechanism of sns5 function in the erythroid genome but also reassure the use of sns5 to improve the performance of gene therapy vectors.
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Affiliation(s)
- Elena Baiamonte
- 1 Campus of Haematology Franco e Piera Cutino, Villa Sofia-Cervello Hospital , Palermo, Italy
| | - Giovanni Spinelli
- 2 Department of Biological, Chemical and Pharmaceutical Sciences and Technologies (STEBICEF), University of Palermo , Palermo, Italy
| | - Aurelio Maggio
- 1 Campus of Haematology Franco e Piera Cutino, Villa Sofia-Cervello Hospital , Palermo, Italy
| | - Santina Acuto
- 1 Campus of Haematology Franco e Piera Cutino, Villa Sofia-Cervello Hospital , Palermo, Italy
| | - Vincenzo Cavalieri
- 2 Department of Biological, Chemical and Pharmaceutical Sciences and Technologies (STEBICEF), University of Palermo , Palermo, Italy
- 3 Mediterranean Center for Human Health Advanced Biotechnologies (CHAB), University of Palermo , Palermo, Italy
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Zolotarev NA, Kyrchanova OV, Maksimenko OG, Georgiev PG. [Recruiting of insulator protein ZIPIC of Drosophila melanogaster to minor binding sites in vivo depends on other DNA-binding transcription factors]. Mol Biol (Mosk) 2015; 49:1016-1021. [PMID: 26710784 DOI: 10.7868/s0026898415060245] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2015] [Accepted: 04/29/2015] [Indexed: 06/05/2023]
Abstract
ZIPIC insulator protein of Drosophila has seven zinc finger domains at the C-terminus. Some of this zinc fingers are involved in binding of specific DNA sequence: CAGGGCTG. ZIPIC can interact only in vivo with minor form of this site (substitution of G to T at position 4). Possible explanation is interaction with additional transcription factors can help ZIPIC to bind minor form of consensus. On the other hand ZIPIC can efficiently bind in vitro other minor form of consensus (substitution of C to A at 6 position).
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Affiliation(s)
- N A Zolotarev
- Institute of Gene Biology, Russian Academy of Sciences, Moscow, 119991 Russia
| | - O V Kyrchanova
- Institute of Gene Biology, Russian Academy of Sciences, Moscow, 119991 Russia
| | - O G Maksimenko
- Institute of Gene Biology, Russian Academy of Sciences, Moscow, 119991 Russia
| | - P G Georgiev
- Institute of Gene Biology, Russian Academy of Sciences, Moscow, 119991 Russia
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Maksimenko O, Kyrchanova O, Bonchuk A, Stakhov V, Parshikov A, Georgiev P. Highly conserved ENY2/Sus1 protein binds to Drosophila CTCF and is required for barrier activity. Epigenetics 2014; 9:1261-70. [PMID: 25147918 DOI: 10.4161/epi.32086] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
Abstract
Chromatin insulators affect interactions between promoters and enhancers/silencers and function as barriers for the spreading of repressive chromatin. Drosophila insulator protein dCTCF marks active promoters and boundaries of many histone H3K27 trimethylation domains associated with repressed chromatin. In particular, dCTCF binds to such boundaries between the parasegment-specific regulatory domains of the Bithorax complex. Here we demonstrate that the evolutionarily conserved protein ENY2 is recruited to the zinc-finger domain of dCTCF and is required for the barrier activity of dCTCF-dependent insulators in transgenic lines. Inactivation of ENY2 by RNAi in BG3 cells leads to the spreading of H3K27 trimethylation and Pc protein at several dCTCF boundaries. The results suggest that evolutionarily conserved ENY2 is responsible for barrier activity mediated by the dCTCF protein.
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Affiliation(s)
- Oksana Maksimenko
- Laboratory of Gene Expression Regulation in Development; Institute of Gene Biology; Russian Academy of Sciences; Moscow, Russia
| | - Olga Kyrchanova
- Group of Transcriptional Regulation; Institute of Gene Biology; Russian Academy of Sciences; Moscow, Russia
| | - Artem Bonchuk
- Group of Transcriptional Regulation; Institute of Gene Biology; Russian Academy of Sciences; Moscow, Russia
| | - Viacheslav Stakhov
- Laboratory of Gene Expression Regulation in Development; Institute of Gene Biology; Russian Academy of Sciences; Moscow, Russia
| | - Alexander Parshikov
- Department of the Control of Genetic Processes; Institute of Gene Biology; Russian Academy of Sciences; Moscow, Russia
| | - Pavel Georgiev
- Department of the Control of Genetic Processes; Institute of Gene Biology; Russian Academy of Sciences; Moscow, Russia
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Rincón-Arano H, Furlan-Magaril M, Recillas-Targa F. Protection against telomeric position effects by the chicken cHS4 beta-globin insulator. Proc Natl Acad Sci U S A 2007; 104:14044-9. [PMID: 17715059 PMCID: PMC1955792 DOI: 10.1073/pnas.0704999104] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/28/2007] [Indexed: 12/26/2022] Open
Abstract
Epigenetic silencing of genes relocated near telomeres, termed telomeric position effect, has been extensively studied in yeast and more recently in vertebrates. However, protection of a transgene against telomeric position effects by chromatin insulators has not yet been addressed. In this work we investigated the capacity of the chicken beta-globin insulator cHS4 to shield a transgene against silencing by telomeric heterochromatin. Using telomeric repeats, we targeted transgene integration into telomeres of the chicken cell line HD3. When the chicken cHS4 insulator is incorporated to the transgene, we observe a sustained gene expression of single-copy integrants that can be maintained for >100 days of continuous culture. However, uninsulated single-copy clones showed an accelerated gene expression extinction profile. Unexpectedly, telomeric silencing was not reversed with trichostatin A or nicotidamine. In contrast, significant reactivation was obtained with 5-aza-2'-deoxycytidine, consistent with the subtelomeric DNA methylation status. Strikingly, insulated transgenes integrated into telomeric regions were enriched in histone methylation, such as H3K4me2 and H3K79me2, but not in histone acetylation. Furthermore, the cHS4 insulator counteracts telomeric position effects in an upstream stimulatory factor-independent manner. Our results suggest that this insulator has the capacity to adapt to different chromatin propagation signals in distinct insertional epigenome environments.
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Affiliation(s)
- Héctor Rincón-Arano
- Instituto de Fisiología Celular, Departamento de Genética Molecular, Universidad Nacional Autónoma de México, Apartado Postal 70-242, 04510 México, D.F., México
| | - Mayra Furlan-Magaril
- Instituto de Fisiología Celular, Departamento de Genética Molecular, Universidad Nacional Autónoma de México, Apartado Postal 70-242, 04510 México, D.F., México
| | - Félix Recillas-Targa
- Instituto de Fisiología Celular, Departamento de Genética Molecular, Universidad Nacional Autónoma de México, Apartado Postal 70-242, 04510 México, D.F., México
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Pant V, Mariano P, Kanduri C, Mattsson A, Lobanenkov V, Heuchel R, Ohlsson R. The nucleotides responsible for the direct physical contact between the chromatin insulator protein CTCF and the H19 imprinting control region manifest parent of origin-specific long-distance insulation and methylation-free domains. Genes Dev 2003; 17:586-90. [PMID: 12629040 PMCID: PMC196004 DOI: 10.1101/gad.254903] [Citation(s) in RCA: 127] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2002] [Accepted: 01/08/2003] [Indexed: 11/24/2022]
Abstract
The repression of the maternally inherited Igf2 allele has been proposed to depend on a methylation-sensitive chromatin insulator organized by the 11 zinc finger protein CTCF at the H19 imprinting control region (ICR). Here we document that point mutations of the nucleotides in physical contact with CTCF within the endogenous H19 ICR lead to loss of CTCF binding and Igf2 imprinting only when passaged through the female germline. This effect is accompanied by a significant loss of methylation protection of the maternally derived H19 ICR. Because CTCF interacts with other imprinting control regions, it emerges as a central factor responsible for interpreting and propagating gamete-derived epigenetic marks and for organizing epigenetically controlled expression domains.
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Affiliation(s)
- Vinod Pant
- Department of Development & Genetics, Evolution Biology Centre, Uppsala University, S-752 36 Uppsala, Sweden
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