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| 2. |
- Chernukhin, Igor, et al.
(författare)
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CTCF Interacts with and Recruits the Largest Subunit of RNA Polymerase II to CTCF Target Sites Genome-Wide
- 2007
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Ingår i: Molecular and Cellular Biology. - 0270-7306 .- 1098-5549. ; 27:5, s. 1631-1648
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Tidskriftsartikel (refereegranskat)abstract
- CTCF is a transcription factor with highly versatile functions ranging from gene activation and repression to the regulation of insulator function and imprinting. Although many of these functions rely on CTCF-DNA interactions, it is an emerging realization that CTCF-dependent molecular processes involve CTCF interactions with other proteins. In this study, we report the association of a subpopulation of CTCF with the RNA polymerase II (Pol II) protein complex. We identified the largest subunit of Pol II (LS Pol II) as a protein significantly colocalizing with CTCF in the nucleus and specifically interacting with CTCF in vivo and in vitro. The role of CTCF as a link between DNA and LS Pol II has been reinforced by the observation that the association of LS Pol II with CTCF target sites in vivo depends on intact CTCF binding sequences. "Serial" chromatin immunoprecipitation (ChIP) analysis revealed that both CTCF and LS Pol II were present at the β-globin insulator in proliferating HD3 cells but not in differentiated globin synthesizing HD3 cells. Further, a single wild-type CTCF target site (N-Myc-CTCF), but not the mutant site deficient for CTCF binding, was sufficient to activate the transcription from the promoterless reporter gene in stably transfected cells. Finally, a ChIP-on-ChIP hybridization assay using microarrays of a library of CTCF target sites revealed that many intergenic CTCF target sequences interacted with both CTCF and LS Pol II. We discuss the possible implications of our observations with respect to plausible mechanisms of transcriptional regulation via a CTCF-mediated direct link of LS Pol II to the DNA.
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| 3. |
- Gao, Wenqiang, et al.
(författare)
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Construction of diluted magnetic semiconductor to endow nonmagnetic semiconductor with spin-regulated photocatalytic performance
- 2023
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Ingår i: Nano Energy. - : Elsevier BV. - 2211-2855 .- 2211-3282. ; 110
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Tidskriftsartikel (refereegranskat)abstract
- Electron spinning polarization has now attracted extensive attention due to its significant effect on improving catalysis. However, only a few photocatalysts possess the electron spinning modification property. How to endow nonmagnetic semiconductors with spintronic properties to realize spinning-regulated photocatalysis enhancement is a great challenge. Herein, based on the diluted magnetic semiconductor concept, we proposed a novel strategy to endow photocatalysts a spinning tunable property. In this work, a diluted magnetic semiconductor photocatalyst with spin polarization was constructed by only doping magnetic ions into CdS/MoS2. The spin polarization with a higher ferromagnetic property was detected in CdS and MoS2 of the Ni-doped CdS/MoS2 diluted magnetic semiconductor photocatalyst. The magnetic field-derived spin polarization reduced the charge recombination in CdS, and improved the interface transfer efficiency between CdS and MoS2, which resulted in a 3.89-fold improvement of the photocatalytic hydrogen production under an external magnetic field. This work provides a new strategy to endow nonmagnetic semiconductors with spin-regulated photocatalytic performance by constructing diluted magnetic semiconductor photocatalysts.
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| 4. |
- Han, Xili, et al.
(författare)
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Low Impact Thinking of the Spongy City Construction in Built-Up Areas from the Perspective of Sustainable Urban Design
- 2016
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Ingår i: International Low Impact Development Conference China 2016 : LID Applications in Sponge City Projects - LID Applications in Sponge City Projects. - Reston, VA : American Society of Civil Engineers. - 9780784481042 ; , s. 328-338
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Konferensbidrag (övrigt vetenskapligt/konstnärligt)abstract
- Sponge city construction can improve cities’ ability to adapt to the environment change and the ability to cope with floods, and it can also prompt cities’ development to be more healthy and sustainable. However, the process itself of sponge city construction may also has impact on the environment especially in built-up areas, to reduce the impact, the rainwater landscape design needs to integrate sustainable thoughts as follows: (1) balancing earthwork on site. Borrowing the traditional Chinese concept of "dig lake and pile mountain", providing earthwork balance on site by adjusting the micro-topography. (2) Protecting trees and bushes on site. When introducing bio-retention ponds to the built-up area with new plants which will be drought-resistant and wet-resistant, perennial, and with low maintenance, the designers need to think about how to protect and rearrange the existing plants especially trees and bushes at the same time which are relatively stable and mature in green spaces of old town. (3) Recycling the existing paving materials. Impermeable paving material on sidewalk, square, pedestrian area, parking area, etc. will be replaced by permeable concrete, permeable bricks, gravel, other permeable materials, and waterway kerbs. These abandoned materials could be recycled on site, such as use of the old concrete slabs, bricks building short stone walls to divide space or seats for people to rest, and it will reduce a lot of construction waste and avoid the pollution of new material consummations to the environment. (4) Taking the opportunity of spongy city construction to improve urban non-motor vehicle traffic environment, raising bike lanes along roads outside blocks and small roads inside blocks with permeable asphalt to improve walking and biking environment in cities. (5) Making public open spaces such as squares and green spaces support more staying activities with the opportunity of introducing rain garden to these areas. This is a kind of sustainable urban design point of view. Following the principle of minimum energy and material consumption and reducing the impact of sponge city construction itself on the environment will avoid a new round of environmental problems and resource waste. It has important significance to the construction of ecological city.
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| 5. |
- Mukhopadhyay, Rituparna, et al.
(författare)
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The Binding Sites for the Chromatin Insulator Protein CTCF Map to DNA Methylation-Free Domains Genome-Wide
- 2004
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Ingår i: Genome Research. - : Cold Spring Harbor Laboratory. - 1088-9051 .- 1549-5469. ; 14:8, s. 1594-1602
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Tidskriftsartikel (refereegranskat)abstract
- All known vertebrate chromatin insulators interact with the highly conserved, multivalent 11-zinc finger nuclear factor CTCF to demarcate expression domains by blocking enhancer or silencer signals in a position-dependent manner. Recent observations document that the properties of CTCF include reading and propagating the epigenetic state of the differentially methylated H19 imprinting control region. To assess whether these findings may reflect a universal role for CTCF targets, we identified more than 200 new CTCF target sites by generating DNA microarrays of clones derived from chromatin-immunopurified (ChIP) DNA followed by ChIP-on-chip hybridization analysis. Target sites include not only known loci involved in multiple cellular functions, such as metabolism, neurogenesis, growth, apoptosis, and signalling, but potentially also heterochromatic sequences. Using a novel insulator trapping assay, we also show that the majority of these targets manifest insulator functions with a continuous distribution of stringency. As these targets are generally DNA methylation-free as determined by antibodies against 5-methylcytidine and a methyl-binding protein (MBD2), a CTCF-based network correlates with genome-wide epigenetic states.
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| 6. |
- Yu, Wenqiang, et al.
(författare)
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Poly(ADP-ribosyl)ation regulates CTCF-dependent chromatin insulation
- 2004
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Ingår i: Nature Genetics. - : Springer Science and Business Media LLC. - 1061-4036 .- 1546-1718. ; 36:10, s. 1105-1110
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Tidskriftsartikel (refereegranskat)abstract
- Chromatin insulators demarcate expression domains by blocking the cis effects of enhancers or silencers in a position-dependent manner1, 2. We show that the chromatin insulator protein CTCF carries a post-translational modification: poly(ADP-ribosyl)ation. Chromatin immunoprecipitation analysis showed that a poly(ADP-ribosyl)ation mark, which exclusively segregates with the maternal allele of the insulator domain in the H19 imprinting control region, requires the bases that are essential for interaction with CTCF3. Chromatin immunoprecipitation−on−chip analysis documented that the link between CTCF and poly(ADP-ribosyl)ation extended to more than 140 mouse CTCF target sites. An insulator trap assay showed that the insulator function of most of these CTCF target sites is sensitive to 3-aminobenzamide, an inhibitor of poly(ADP-ribose) polymerase activity. We suggest that poly(ADP-ribosyl)ation imparts chromatin insulator properties to CTCF at both imprinted and nonimprinted loci, which has implications for the regulation of expression domains and their demise in pathological lesions.
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