A5041083786- Epigenetics and DNA Methylation
- Cancer-related gene regulation
- RNA modifications and cancer
- HIV Research and Treatment
- Vascular Malformations Diagnosis and Treatment
- Genomics and Chromatin Dynamics
- Malaria Research and Control
- Intracranial Aneurysms: Treatment and Complications
- Moyamoya disease diagnosis and treatment
- Genetic Syndromes and Imprinting
- Acute Myeloid Leukemia Research
- Tea Polyphenols and Effects
- Cancer Genomics and Diagnostics
- Intracerebral and Subarachnoid Hemorrhage Research
- Coffee research and impacts
- vaccines and immunoinformatics approaches
- Mass Spectrometry Techniques and Applications
- Estrogen and related hormone effects
- Islamic Finance and Communication
- Adenosine and Purinergic Signaling
- Cerebrospinal fluid and hydrocephalus
- Virology and Viral Diseases
- Nuclear Physics and Applications
- Cholesterol and Lipid Metabolism
- Metabolism, Diabetes, and Cancer
Indian Institute of Technology Madras
2021-2024
Rajiv Gandhi Centre for Biotechnology
2016-2023
University of Stuttgart
2012-2022
Constructor University
2010-2012
Max Planck Society
2010
Max Planck Innovation
2010
The Dnmt3a DNA methyltransferase contains in its N-terminal part a PWWP domain that is involved chromatin targeting. Here, we have investigated the interaction of with modified histone tails using peptide arrays and show it specifically recognizes 3 lysine 36 trimethylation mark. H3K36me3 known to be repressive modification correlated methylation mammals heterochromatin <i>Schizosaccharomyces pombe</i>. These results were confirmed by equilibrium binding studies pulldown experiments native...
Using peptide arrays and binding to native histone proteins, we show that the ADD domain of Dnmt3a specifically interacts with H3 1–19 tail. Binding is disrupted by di- trimethylation K4, phosphorylation T3, S10 or T11 acetylation K4. We did not observe H4 The Dnmt3b shows same specificity, suggesting distinct biological functions both enzymes are related their domains. To establish a functional role unmodified tails, analyzed DNA methylation in vitro reconstituted chromatin Dnmt3a2,...
DNA methyltransferases (DNMT) are promising drug targets in cancer provided that new, more specific, and chemically stable inhibitors discovered. Among the non-nucleoside DNMT inhibitors, N-phthaloyl-l-tryptophan 1 (RG108) was first identified as inhibitor of DNMT1. Here, analogues were synthesized to understand its interaction with DNMT. The indole, carboxylate, phthalimide moieties modified. Homologated conformationally constrained prepared. latter from prolinohomotryptophan derivatives...
DNA methylation is a central epigenetic modification that established by de novo methyltransferases. The mechanisms underlying the generation of genomic patterns are still poorly understood. Using mass spectrometry and phosphospecific Dnmt3a antibody, we demonstrate CK2 phosphorylates endogenous at two key residues located near its PWWP domain, thereby downregulating ability to methylate DNA. Genome-wide analysis shows primarily modulates CpG several repeats, most notably Alu SINEs. This...
Abstract DNA methylation is involved in the regulation of gene expression and plays an important role normal developmental processes diseases, such as cancer. methyltransferases are enzymes responsible for on position 5 cytidine a CpG context. In order to identify characterize novel inhibitors these enzymes, we developed fluorescence‐based throughput screening by using short duplex immobilized 96‐well plates. We have screened 114 flavones flavanones inhibition murine catalytic Dnmt3a/3L...
Abstract Background Black tea is, second only to water, the most consumed beverage globally. Previously, inhibition of DNA methyltransferase 1 was shown by dietary polyphenols and epi-gallocatechin gallate (EGCG), main polyphenolic constituent green tea, 5-caffeoyl quinic acid, phenolic coffee bean. Results We studied 3a a series from black such as theaflavins thearubigins chlorogenic acid derivatives coffee. For theaflavin 3,3 digallate IC 50 values in lower micro molar range were observed,...
Quinoline derivative SGI-1027 (N-(4-(2-amino-6-methylpyrimidin-4-ylamino)phenyl)-4-(quinolin-4-ylamino)benzamide) was first described in 2009 as a potent inhibitor of DNA methyltransferase (DNMT) 1, 3A and 3B. Based on molecular modeling studies, performed using the crystal structure Haemophilus haemolyticus cytosine-5 (MHhaI C5 DNMT), which suggested that quinoline aminopyridimine moieties are important for interaction with substrates protein, we designed synthesized 25 derivatives. Among...
In order to discover new inhibitors of the DNA methyltransferase 3A/3L complex, we used a medium-throughput nonradioactive screen on random collection 1120 small organic compounds. After primary hit detection against methylation activity murine Dnmt3A/3L catalytic further evaluated EC50 12 most potent hits as well their cytotoxicity DU145 prostate cancer cultured cells. Interestingly, showed low micromolar activities and little cytotoxicity. Dichlone, halogenated naphthoquinone, classically...
Abstract DNA methyltransferases (DNMTs) are responsible for methylation, an epigenetic modification involved in gene regulation. Families of conjugates procainamide, inhibitor DNMT1, were conceived and produced by rapid synthetic pathways. Six compounds resulted potent inhibitors the murine catalytic Dnmt3A/3L complex human at least 50 times greater than that parent compounds. The showed selectivity C5 methyltransferases. cytotoxicity was validated on two tumour cell lines (DU145 HCT116)...
The catalytic domain of Dnmt3a cooperatively multimerizes on DNA forming nucleoprotein filaments. Based modeling, we identified the interface complexes binding next to each other and disrupted it by charge reversal critical residues. This prevented cooperative multimerization DNA, as shown loss complex formation in electrophoretic mobility shift assay, cooperativity solution, a characteristic 8- 10-bp periodicity methylation direct imaging protein–DNA scanning force microscopy....
The Dnmt3a DNA methyltransferase has been shown to bind cooperatively and form large multimeric protein/DNA fibers. However, it also reported methylate in a processive manner, property that is incompatible with fiber formation. We show here the methylation rate of increases more than linearly increasing enzyme concentration on long substrate, but not short 30-mer oligonucleotide substrate. addition catalytically inactive mutant, which carries an amino acid exchange catalytic center, by wild...
The DNMT3A R882H mutation is frequently observed in acute myeloid leukemia (AML). It located the subunit and DNA binding interface of has been reported to cause a reduction activity dominant negative effects. We investigated mechanistic consequences on showing roughly 40% overall methylation activity. Biochemical assays demonstrated that does not change affinity, protein stability or subnuclear distribution DNMT3A. Strikingly, experiments revealed pronounced changes flanking sequence...
Abstract The N‐terminal regulatory part of DNA methyltransferase 1 (Dnmt1) contains a replication foci targeting sequence (RFTS) domain, which is involved in the recruitment Dnmt1 to forks. RFTS domain has been observed crystal structure bind catalytic enzyme and block its centre. Removal led activation Dnmt1, thus suggesting an autoinhibitory role this domain. Here, we destabilised interaction with by site‐directed mutagenesis purified corresponding variants. Our data show that these...
Despite their central importance in mammalian development, the mechanisms that regulate DNA methylation machinery and thereby generation of genomic patterns are still poorly understood. Here, we identify 5mC-binding protein MeCP2 as a direct strong interactor methyltransferase 3 (DNMT3) proteins. We mapped interaction interface to transcriptional repression domain ADD DNMT3A find binding strongly inhibits activity vitro. This effect was reinforced by cellular studies where global reduction...
Among the proteins predicted to be a part of DExD box RNA helicase family, functions DDX49 are unknown. Here, we characterize enzymatic activities and by comparing its properties with well-studied helicase, DDX39B. We find that exhibits robust ATPase activity, significantly higher than is required for efficient export poly (A)+ from nucleus in splicing-independent manner. Furthermore, resident protein nucleolus regulates steady state levels pre-ribosomal regulating transcription stability....
The DNA methyltransferase DNMT3A R882H mutation is observed in 25% of all AML patients. active as tetramer and the located one subunit/subunit interfaces. Previous work has reported that formation mixed wildtype/R882H complexes leads to a strong loss catalytic activity vitro methylation assays (Russler-Germain et al., 2014, Cancer Cell 25:442-454). To investigate this effect further, we have prepared by incubation individually purified subunits domain full-length DNMT3A2. In addition, used...
Abstract Protein arginine methyltransferase 3 (PRMT3) regulates protein functions by introducing asymmetric dimethylation marks at the residues in proteins. However, very little is known about interaction partners of PRMT3 and their functional outcomes. Using yeast-two hybrid screening, we identified Retinal dehydrogenase 1 (ALDH1A1) as a potential partner confirmed this using different methods. ALDH1A1 variety cellular processes catalyzing conversion retinaldehyde to retinoic acid. By...
Abstract Background Plasmodium falciparum exhibits high translational plasticity during its development in RBCs, yet the regulation at post-transcriptional level is not well understood. The N 6 -methyl adenosine (m6A) an important epigenetic modification primarily present on mRNA that controls levels of transcripts and efficiency translation eukaryotes. Recently, dynamics m6A mRNAs all three developmental stages P. RBCs have been profiled; however, proteins regulate containing parasites are...
27-hydroxycholesterol (27-HC) is the first known endogenous selective estrogen receptor modulator (SERM), and its elevation from normal levels closely associated with breast cancer. A plethora of evidence suggests that aberrant epigenetic signatures in cancer cells can result differential responses to various chemotherapeutics often leads development resistant cells. Such changes are mostly dictated by microenvironment. The local concentration oxygen metabolites microenvironment influence...
Epigenetic machinery has emerged as a central player in gene regulation and chromatin organization Plasmodium spp. modifications on histones their role antigenic variation P. falciparum are widely studied. Recent discoveries nucleic acid methylome exciting provide new dimension to the apicomplexan protozoan parasite's regulatory process. Reports have confirmed that N6-methyl adenosine (m6A) methylation plays crucial translational plasticity of human malaria parasite during its development...