Publications by authors named "Chenxu Zhu"

20 Publications

  • Page 1 of 1

Mutation of P-element somatic inhibitor induces male sterility in the diamondback moth, Plutella xylostella.

Pest Manag Sci 2021 Apr 11. Epub 2021 Apr 11.

CAS Key Laboratory of Insect Developmental and Evolutionary Biology, CAS Center for Excellence in Molecular Plant Sciences/Institute of Plant Physiology and Ecology, Shanghai, China.

Background: Genetic manipulation of sex determination pathways in insects provides the basis for a broad range of strategies to benefit agricultural security and human health. The P-element somatic inhibitor (PSI) protein, an exon splicing silencer that promotes male-specific splicing of dsx, plays a critical role in male sexual differentiation and development. The functions of PSI have been characterized in the lepidopteran model species Bombyx mori. However, the molecular mechanism and functions of PSI in Plutella xylostella, a worldwide agricultural pest and taxonomically basal species, are still unknown.

Results: Here we identified PxPSI transcripts and analyzed their spatiotemporal expression pattern in P. xylostella. Multiple sequence alignment revealed that PxPSI contains four KH domains and is highly conserved in lepidopterans. We used the CRISPR-Cas9 system to generate mutations of the PxPSI genomic locus. Disruptions of PxPSI caused male-specific defects in internal and external genitals. In addition, we detected female-specific Pxdsx transcripts in PxPSI male mutants. Mutations also caused changes in expression of several sex-biased genes and induced male sterility.

Conclusion: Our study demonstrates that PxPSI plays a key role in male sex determination in P. xylostella and suggests a potential molecular target for genetic-based pest management in lepidopteran pests.
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http://dx.doi.org/10.1002/ps.6413DOI Listing
April 2021

Joint profiling of histone modifications and transcriptome in single cells from mouse brain.

Nat Methods 2021 03 15;18(3):283-292. Epub 2021 Feb 15.

Ludwig Institute for Cancer Research, La Jolla, CA, USA.

Genome-wide profiling of histone modifications can reveal not only the location and activity state of regulatory elements, but also the regulatory mechanisms involved in cell-type-specific gene expression during development and disease pathology. Conventional assays to profile histone modifications in bulk tissues lack single-cell resolution. Here we describe an ultra-high-throughput method, Paired-Tag, for joint profiling of histone modifications and transcriptome in single cells to produce cell-type-resolved maps of chromatin state and transcriptome in complex tissues. We used this method to profile five histone modifications jointly with transcriptome in the adult mouse frontal cortex and hippocampus. Integrative analysis of the resulting maps identified distinct groups of genes subject to divergent epigenetic regulatory mechanisms. Our single-cell multiomics approach enables comprehensive analysis of chromatin state and gene regulation in complex tissues and characterization of gene regulatory programs in the constituent cell types.
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http://dx.doi.org/10.1038/s41592-021-01060-3DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7954905PMC
March 2021

Research progress of ulinastatin in the treatment of liver diseases.

Int J Clin Exp Pathol 2020 1;13(11):2720-2726. Epub 2020 Nov 1.

Department of Anesthesiology, Yi Jishan Hospital Affiliated to Wannan Medical College Wuhu, Anhui, China.

Ulinastatin (UTI) is a trypsin inhibitor observed in urine. UTI can treat some diseases by inhibiting the broad-spectrum hydrolysis activity of various enzymes and other pharmacological effects. UTI can widely treat pancreatitis, systemic multiple organ dysfunction syndrome, circulatory failure, and toxic shock clinically. The liver is a major metabolic organ of the human body. Various biological metabolic reactions require the liver's participation. When various physical and chemical factors drive the body, it will damage the liver to varying degrees. As a clinically effective drug, UTI is also known to treat some liver diseases. This article mainly describes UTI's research progress in treating septic liver injury, hepatitis, liver fibrosis, autoimmune liver disease with liver failure, and liver ischemia-reperfusion injury.
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http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7716140PMC
November 2020

Transposase-assisted tagmentation of RNA/DNA hybrid duplexes.

Elife 2020 07 23;9. Epub 2020 Jul 23.

State Key Laboratory of Protein and Plant Gene Research, School of Life Sciences, Peking University, Beijing, China.

Tn5-mediated transposition of double-strand DNA has been widely utilized in various high-throughput sequencing applications. Here, we report that the Tn5 transposase is also capable of direct tagmentation of RNA/DNA hybrids in vitro. As a proof-of-concept application, we utilized this activity to replace the traditional library construction procedure of RNA sequencing, which contains many laborious and time-consuming processes. Results of ransposase-assisted NA/DN hybrids o-tagmntation (termed 'TRACE-seq') are compared to traditional RNA-seq methods in terms of detected gene number, gene body coverage, gene expression measurement, library complexity, and differential expression analysis. At the meantime, TRACE-seq enables a cost-effective one-tube library construction protocol and hence is more rapid (within 6 hr) and convenient. We expect this tagmentation activity on RNA/DNA hybrids to have broad potentials on RNA biology and chromatin research.
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http://dx.doi.org/10.7554/eLife.54919DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7402673PMC
July 2020

Single-cell multimodal omics: the power of many.

Nat Methods 2020 01;17(1):11-14

Ludwig Institute for Cancer Research, La Jolla, CA, USA.

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http://dx.doi.org/10.1038/s41592-019-0691-5DOI Listing
January 2020

Differential roles of human PUS10 in miRNA processing and tRNA pseudouridylation.

Nat Chem Biol 2020 02 9;16(2):160-169. Epub 2019 Dec 9.

State Key Laboratory of Protein and Plant Gene Research, School of Life Sciences, Peking University, Beijing, China.

Pseudouridine synthases (PUSs) are responsible for installation of pseudouridine (Ψ) modification in RNA. However, the activity and function of the PUS enzymes remain largely unexplored. Here we focus on human PUS10 and find that it co-expresses with the microprocessor (DROSHA-DGCR8 complex). Depletion of PUS10 results in a marked reduction of the expression level of a large number of mature miRNAs and concomitant accumulation of unprocessed primary microRNAs (pri-miRNAs) in multiple human cells. Mechanistically, PUS10 directly binds to pri-miRNAs and interacts with the microprocessor to promote miRNA biogenesis. Unexpectedly, this process is independent of the catalytic activity of PUS10. Additionally, we develop a sequencing method to profile Ψ in the tRNAome and report PUS10-dependent Ψ sites in tRNA. Collectively, our findings reveal differential functions of PUS10 in nuclear miRNA processing and in cytoplasmic tRNA pseudouridylation.
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http://dx.doi.org/10.1038/s41589-019-0420-5DOI Listing
February 2020

An ultra high-throughput method for single-cell joint analysis of open chromatin and transcriptome.

Nat Struct Mol Biol 2019 11 6;26(11):1063-1070. Epub 2019 Nov 6.

Ludwig Institute for Cancer Research, La Jolla, CA, USA.

Simultaneous profiling of transcriptome and chromatin accessibility within single cells is a powerful approach to dissect gene regulatory programs in complex tissues. However, current tools are limited by modest throughput. We now describe an ultra high-throughput method, Paired-seq, for parallel analysis of transcriptome and accessible chromatin in millions of single cells. We demonstrate the utility of Paired-seq for analyzing the dynamic and cell-type-specific gene regulatory programs in complex tissues by applying it to mouse adult cerebral cortex and fetal forebrain. The joint profiles of a large number of single cells allowed us to deconvolute the transcriptome and open chromatin landscapes in the major cell types within these brain tissues, infer putative target genes of candidate enhancers, and reconstruct the trajectory of cellular lineages within the developing forebrain.
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http://dx.doi.org/10.1038/s41594-019-0323-xDOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7231560PMC
November 2019

Turning the Tap: Conformational Control of Quantum Interference to Modulate Single-Molecule Conductance.

Angew Chem Int Ed Engl 2019 Dec 31;58(52):18987-18993. Epub 2019 Oct 31.

Department of Physics, Lancaster University, Lancaster, LA1 4YB, UK.

Together with the more intuitive and commonly recognized conductance mechanisms of charge-hopping and tunneling, quantum-interference (QI) phenomena have been identified as important factors affecting charge transport through molecules. Consequently, establishing simple and flexible molecular-design strategies to understand, control, and exploit QI in molecular junctions poses an exciting challenge. Here we demonstrate that destructive quantum interference (DQI) in meta-substituted phenylene ethylene-type oligomers (m-OPE) can be tuned by changing the position and conformation of methoxy (OMe) substituents at the central phenylene ring. These substituents play the role of molecular-scale taps, which can be switched on or off to control the current flow through a molecule. Our experimental results conclusively verify recently postulated magic-ratio and orbital-product rules, and highlight a novel chemical design strategy for tuning and gating DQI features to create single-molecule devices with desirable electronic functions.
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http://dx.doi.org/10.1002/anie.201909461DOI Listing
December 2019

Single-Cell 5fC Sequencing.

Methods Mol Biol 2019 ;1979:251-267

State Key Laboratory of Protein and Plant Gene Research, School of Life Sciences, Peking University, Beijing, People's Republic of China.

Active DNA demethylation plays important roles in the epigenetic reprogramming of developmental processes. 5-formylcytosine (5fC) is produced during active demethylation of 5-methylcytosine (5mC). Here, we describe a technique called CLEVER-seq (Chemical-labeling-enabled C-to-T conversion sequencing), which detects the whole genome 5fC distribution at single-base and single-cell resolution. CLEVER-seq is suitable for the analysis of precious samples such as early embryos and laser microdissection captured samples.
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http://dx.doi.org/10.1007/978-1-4939-9240-9_16DOI Listing
August 2019

Unnatural Cytosine Bases Recognized as Thymines by DNA Polymerases by the Formation of the Watson-Crick Geometry.

Angew Chem Int Ed Engl 2019 01 5;58(1):130-133. Epub 2018 Dec 5.

School of Life Sciences, Department of Chemical Biology and Synthetic and Functional Biomolecules Center, College of Chemistry and Molecular Engineering and Peking-Tsinghua Center for Life Sciences, Peking University, Beijing, 100871, China.

The emergence of unnatural DNA bases provides opportunities to demystify the mechanisms by which DNA polymerases faithfully decode chemical information on the template. It was previously shown that two unnatural cytosine bases (termed "M-fC" and "I-fC"), which are chemical labeling adducts of the epigenetic base 5-formylcytosine, can induce C-to-T transition during DNA amplification. However, how DNA polymerases recognize such unnatural cytosine bases remains enigmatic. Herein, crystal structures of unnatural cytosine bases pairing to dA/dG in the KlenTaq polymerase-host-guest complex system and pairing to dATP in the KlenTaq polymerase active site were determined. Both M-fC and I-fC base pair with dA/dATP, but not with dG, in a Watson-Crick geometry. This study reveals that the formation of the Watson-Crick geometry, which may be enabled by the A-rule, is important for the recognition of unnatural cytosines.
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http://dx.doi.org/10.1002/anie.201807845DOI Listing
January 2019

Bisulfite-Free, Nanoscale Analysis of 5-Hydroxymethylcytosine at Single Base Resolution.

J Am Chem Soc 2018 10 4;140(41):13190-13194. Epub 2018 Oct 4.

State Key Laboratory of Protein and Plant Gene Research, School of Life Sciences , Peking University , Beijing 100871 , China.

High-resolution detection of genome-wide 5-hydroxymethylcytosine (5hmC) sites of small-scale samples remains challenging. Here, we present hmC-CATCH, a bisulfite-free, base-resolution method for the genome-wide detection of 5hmC. hmC-CATCH is based on selective 5hmC oxidation, chemical labeling and subsequent C-to-T transition during PCR. Requiring only nanoscale input genomic DNA samples, hmC-CATCH enabled us to detect genome-wide hydroxymethylome of human embryonic stem cells in a cost-effective manner. Further application of hmC-CATCH to cell-free DNA (cfDNA) of healthy donors and cancer patients revealed base-resolution hydroxymethylome in the human cfDNA for the first time. We anticipate that our chemical biology approach will find broad applications in hydroxymethylome analysis of limited biological and clinical samples.
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http://dx.doi.org/10.1021/jacs.8b08297DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6423965PMC
October 2018

Genome-wide mapping reveals that deoxyuridine is enriched in the human centromeric DNA.

Nat Chem Biol 2018 07 21;14(7):680-687. Epub 2018 May 21.

State Key Laboratory of Protein and Plant Gene Research, School of Life Sciences, and Peking-Tsinghua Center for Life Sciences, Peking University, Beijing, China.

Uracil in DNA can be generated by cytosine deamination or dUMP misincorporation; however, its distribution in the human genome is poorly understood. Here we present a selective labeling and pull-down technology for genome-wide uracil profiling and identify thousands of uracil peaks in three different human cell lines. Surprisingly, uracil is highly enriched at the centromere of the human genome. Using mass spectrometry, we demonstrate that human centromeric DNA contains a higher level of uracil. We also directly verify the presence of uracil within two centromeric uracil peaks on chromosomes 6 and 11. Moreover, centromeric uracil is preferentially localized within the binding regions of the centromere-specific histone CENP-A and can be excised by human uracil-DNA glycosylase UNG. Collectively, our approaches allow comprehensive analysis of uracil in the human genome and provide robust tools for mapping and future functional studies of uracil in DNA.
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http://dx.doi.org/10.1038/s41589-018-0065-9DOI Listing
July 2018

Deciphering TAL effectors for 5-methylcytosine and 5-hydroxymethylcytosine recognition.

Nat Commun 2017 10 12;8(1):901. Epub 2017 Oct 12.

State Key Laboratory of Protein and Plant Gene Research, School of Life Sciences, Peking University, Beijing, 100871, China.

DNA recognition by transcription activator-like effector (TALE) proteins is mediated by tandem repeats that specify nucleotides through repeat-variable diresidues. These repeat-variable diresidues form direct and sequence-specific contacts to DNA bases; hence, TALE-DNA interaction is sensitive to DNA chemical modifications. Here we conduct a thorough investigation, covering all theoretical repeat-variable diresidue combinations, for their recognition capabilities for 5-methylcytosine and 5-hydroxymethylcytosine, two important epigenetic markers in higher eukaryotes. We identify both specific and degenerate repeat-variable diresidues for 5-methylcytosine and 5-hydroxymethylcytosine. Utilizing these novel repeat-variable diresidues, we achieve methylation-dependent gene activation and genome editing in vivo; we also report base-resolution detection of 5hmC in an in vitro assay. Our work deciphers repeat-variable diresidues for 5-methylcytosine and 5-hydroxymethylcytosine, and provides tools for TALE-dependent epigenome recognition.Transcription activator-like effector proteins recognise specific DNA sequences via tandem repeats. Here the authors demonstrate TALEs can recognise the methylated bases 5mC and 5hmC, enabling them to detect epigenetic modifications.
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http://dx.doi.org/10.1038/s41467-017-00860-6DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5638953PMC
October 2017

Single-Cell 5-Formylcytosine Landscapes of Mammalian Early Embryos and ESCs at Single-Base Resolution.

Cell Stem Cell 2017 05 23;20(5):720-731.e5. Epub 2017 Mar 23.

State Key Laboratory of Protein and Plant Gene Research, School of Life Sciences, Peking University, Beijing 100871, PRC; Peking-Tsinghua Center for Life Sciences, Peking University, Beijing 100871, PRC; Department of Chemical Biology and Synthetic and Functional Biomolecules Center, College of Chemistry and Molecular Engineering, Peking University, Beijing 100871, PRC. Electronic address:

Active DNA demethylation in mammals involves ten-eleven translocation (TET) family protein-mediated oxidation of 5-methylcytosine (5mC). However, base-resolution landscapes of 5-formylcytosine (5fC) (an oxidized derivative of 5mC) at the single-cell level remain unexplored. Here, we present "CLEVER-seq" (chemical-labeling-enabled C-to-T conversion sequencing), which is a single-cell, single-base resolution 5fC-sequencing technology, based on biocompatible, selective chemical labeling of 5fC and subsequent C-to-T conversion during amplification and sequencing. CLEVER-seq shows intrinsic 5fC heterogeneity in mouse early embryos, Epi stem cells (EpiSCs), and embryonic stem cells (ESCs). CLEVER-seq of mouse early embryos also reveals the highly patterned genomic distribution and parental-specific dynamics of 5fC during mouse early pre-implantation development. Integrated analysis demonstrates that promoter 5fC production precedes the expression upregulation of a clear set of developmentally and metabolically critical genes. Collectively, our work reveals the dynamics of active DNA demethylation during mouse pre-implantation development and provides an important resource for further functional studies of epigenetic reprogramming in single cells.
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http://dx.doi.org/10.1016/j.stem.2017.02.013DOI Listing
May 2017

Pore Structure of Macroporous Polymers Using Polystyrene/Silica Composite Particles as Pickering Stabilizers.

Langmuir 2016 12 2;32(49):13159-13166. Epub 2016 Dec 2.

State Key Laboratory of Molecular Engineering of Polymers, Collaborative Innovation Center of Polymers and Polymer Composite Materials, Department of Macromolecular Science, Fudan University , Shanghai 200433, P. R. China.

A novel approach for the preparation of interconnected macroporous polymers with a controllable pore structure was reported. The method was based on the polymerization of water-in-oil Pickering high internal phase emulsion (HIPE) stabilized by polystyrene (PS)/silica composite particles. The composite Pickering stabilizers were facilely obtained by mixing positively charged PS microspheres and negatively charged silica nanoparticles, and their amphiphilicity could be delicately tailored by varying the ratio of PS and silica. The droplet size of Pickering HIPEs was characterized using an optical microscope. The pore structure of polymer foams was observed using a scanning electron microscope. The interconnectivity of macroporous polymers was evaluated upon their gas permeability, which was greatly improved after etching PS microspheres included in the Pickering stabilizers with tetrahydrofuran. As a result, fine tailoring of the pore structure of polymer foams could be realized by simply tuning the ratio of PS to silica particles in the composite stabilizer.
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http://dx.doi.org/10.1021/acs.langmuir.6b03285DOI Listing
December 2016

Tautomerization-dependent recognition and excision of oxidation damage in base-excision DNA repair.

Proc Natl Acad Sci U S A 2016 07 27;113(28):7792-7. Epub 2016 Jun 27.

State Key Laboratory of Protein and Plant Gene Research, School of Life Sciences, Peking University, Beijing 100871, China; Peking-Tsinghua Center for Life Sciences, Peking University, Beijing 100871, China; Synthetic and Functional Biomolecules Center, Department of Chemical Biology, College of Chemistry and Molecular Engineering, Peking University, Beijing 100871, China

NEIL1 (Nei-like 1) is a DNA repair glycosylase guarding the mammalian genome against oxidized DNA bases. As the first enzymes in the base-excision repair pathway, glycosylases must recognize the cognate substrates and catalyze their excision. Here we present crystal structures of human NEIL1 bound to a range of duplex DNA. Together with computational and biochemical analyses, our results suggest that NEIL1 promotes tautomerization of thymine glycol (Tg)-a preferred substrate-for optimal binding in its active site. Moreover, this tautomerization event also facilitates NEIL1-catalyzed Tg excision. To our knowledge, the present example represents the first documented case of enzyme-promoted tautomerization for efficient substrate recognition and catalysis in an enzyme-catalyzed reaction.
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http://dx.doi.org/10.1073/pnas.1604591113DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4948311PMC
July 2016

Biochemical and Structural Insights into the Mechanism of DNA Recognition by Arabidopsis ETHYLENE INSENSITIVE3.

PLoS One 2015 9;10(9):e0137439. Epub 2015 Sep 9.

State Key Laboratory of Protein and Plant Gene Research, School of Life Sciences, and Peking-Tsinghua Center for Life Sciences, Peking University, Beijing, China; Department of Chemical Biology and Synthetic and Functional Biomolecules Center, College of Chemistry and Molecular Engineering, Peking University, Beijing, China.

Gaseous hormone ethylene regulates numerous stress responses and developmental adaptations in plants by controlling gene expression via transcription factors ETHYLENE INSENSITIVE3 (EIN3) and EIN3-Like1 (EIL1). However, our knowledge regarding to the accurate definition of DNA-binding domains (DBDs) within EIN3 and also the mechanism of specific DNA recognition by EIN3 is limited. Here, we identify EIN3 82-352 and 174-306 as the optimal and core DBDs, respectively. Results from systematic biochemical analyses reveal that both the number of EIN3-binding sites (EBSs) and the spacing length between two EBSs affect the binding affinity of EIN3; accordingly, a new DNA probe which has higher affinity with EIN3 than ERF1 is also designed. Furthermore, we show that palindromic repeat sequences in ERF1 promoter are not necessary for EIN3 binding. Finally, we provide, to our knowledge, the first crystal structure of EIN3 core DBD, which contains amino acid residues essential for DNA binding and signaling. Collectively, these data suggest the detailed mechanism of DNA recognition by EIN3 and provide an in-depth view at molecular level for the transcriptional regulation mediated by EIN3.
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http://journals.plos.org/plosone/article?id=10.1371/journal.pone.0137439PLOS
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4564277PMC
June 2016

Autofocus using adaptive prediction approximation combined search for the fluorescence microscope in second-generation DNA sequencing system.

Appl Opt 2014 Jul;53(20):4509-18

Autofocus is an important technique for high-speed image acquisition in the second-generation DNA sequencing system, and this paper studies the passive focus algorithm for the system, which consists of two parts: focus measurement (FM) and focus search (FS). Based on the properties of DNA chips' images, we choose the normalized variance as the FM algorithm and develop a new robust FS named adaptive prediction approximation combined search (APACS). APACS utilizes golden section search (GSS) to approximate the focus position and engages the curve-fitting search (CFS) to predict the position simultaneously in every step of GSS. When the difference between consecutive predictions meets the set precision, the search finishes. Otherwise, it ends as GSS. In APACS, we also propose an estimation method, named the combination of centroid estimation and overdetermined equations estimation by least squares solution, to calculate the initial vector for the nonlinear equations in APACS prediction, which reduces the iterations and accelerates the search. The simulation and measured results demonstrate that APACS not only maintains the stability but also reduces the focus time compared with GSS and CFS, which indicates APACS is a robust and fast FS for the fluorescence microscope in a sequencing system.
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http://dx.doi.org/10.1364/AO.53.004509DOI Listing
July 2014

Oxidative demethylation of DNA and RNA mediated by non-heme iron-dependent dioxygenases.

Chem Asian J 2014 Aug 6;9(8):2018-29. Epub 2014 Jun 6.

State Key Laboratory of Protein and Plant Gene Research, School of Life Sciences, Synthetic and Functional Biomolecules Center and Peking-Tsinghua Center for Life Sciences, Peking University, Beijing 100871 (China).

DNA/RNA methylation can be generated by methyltransferases and thus plays a critical role in regulating cellular processes; alternatively, nucleic acid methylation can be produced by methylation agents and is cytotoxic/mutagenic if left unrepaired. Oxidative demethylation mediated by non-heme iron-dependent dioxygenases is an efficient way to reverse either the cellular roles of regulatory methylation or the cytotoxic/mutagenic effects of methylation damage. In this Focus Review we summarize recent advances in the study of nucleic acid dioxygenases exemplified by the TET and AlkB family proteins, with an emphasis on chemical insights from the recent literature. Comparison of the chemical mechanisms of these dioxygenases revealed that differences in the mechanism also contribute significantly to their distinct biological functions.
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http://dx.doi.org/10.1002/asia.201402148DOI Listing
August 2014

Switching demethylation activities between AlkB family RNA/DNA demethylases through exchange of active-site residues.

Angew Chem Int Ed Engl 2014 Apr 5;53(14):3659-62. Epub 2014 Mar 5.

State Key Laboratory of Protein and Plant Gene Research, School of Life Sciences, Synthetic and Functional Biomolecules Center, and Peking-Tsinghua Center for Life Sciences, Peking University, Beijing 100871 (China).

The AlkB family demethylases AlkB, FTO, and ALKBH5 recognize differentially methylated RNA/DNA substrates, which results in their distinct biological roles. Here we identify key active-site residues that contribute to their substrate specificity. Swapping such active-site residues between the demethylases leads to partially switched demethylation activities. Combined evidence from X-ray structures and enzyme kinetics suggests a role of the active-site residues in substrate recognition. Such a divergent active-site sequence may aid the design of selective inhibitors that can discriminate these homologue RNA/DNA demethylases.
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http://dx.doi.org/10.1002/anie.201310050DOI Listing
April 2014