Abstract:
:Cytosine methylation at CpG dinucleotides contributes to the epigenetic maintenance of gene silencing. Dynamic reprogramming of DNA methylation patterns is believed to play a key role during development and differentiation in vertebrates. The mechanisms of DNA demethylation remain unclear and controversial. Here, we present a detailed characterization of the demethylation of an endogenous gene in cultured cells. This demethylation is triggered in a regulatory region by a transcriptional activator, the glucocorticoid receptor. We show that DNA demethylation is an active process, occurring independently of DNA replication, and in a distributive manner without concerted demethylation of cytosines on both strands. We demonstrate that the DNA backbone is cleaved 3' to the methyl cytidine during demethylation, and we suggest that a DNA repair pathway may therefore be involved in this demethylation.
journal_name
Proc Natl Acad Sci U S Aauthors
Kress C,Thomassin H,Grange Tdoi
10.1073/pnas.0601793103subject
Has Abstractpub_date
2006-07-25 00:00:00pages
11112-7issue
30eissn
0027-8424issn
1091-6490pii
0601793103journal_volume
103pub_type
杂志文章abstract::The dramatic loss of Kilimanjaro's ice cover has attracted global attention. The three remaining ice fields on the plateau and the slopes are both shrinking laterally and rapidly thinning. Summit ice cover (areal extent) decreased approximately 1% per year from 1912 to 1953 and approximately 2.5% per year from 1989 to...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章
doi:10.1073/pnas.0906029106
更新日期:2009-11-24 00:00:00
abstract::It is shown that, under certain standard assumptions, such as extended Riemann hypotheses, the scattering matrix varphi(s) for generic Gamma = SL(2, R) is unexpectedly of order 2. This leads to the conjecture that the generic cofinite Gamma has very few Maass cusp forms. ...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章
doi:10.1073/pnas.82.11.3533
更新日期:1985-06-01 00:00:00
abstract::We outline a theory to quantify the interplay of entropic and selective forces on nucleotide organization and apply it to the genomes of single-stranded RNA viruses. We quantify these forces as intensive variables that can easily be compared between sequences, outline a computationally efficient transfer-matrix method...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章
doi:10.1073/pnas.1402285111
更新日期:2014-04-01 00:00:00
abstract::Urodeles and fetal mammals are capable of impressive epimorphic regeneration in a variety of tissues, whereas the typical default response to injury in adult mammals consists of inflammation and scar tissue formation. One component of epimorphic regeneration is the recruitment of resident progenitor and stem cells to ...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章
doi:10.1073/pnas.0905851106
更新日期:2010-02-23 00:00:00
abstract::Clinical studies have revealed that genetic variations in metabotropic glutamate receptor 3 (mGlu3) affect performance on cognitive tasks dependent upon the prefrontal cortex (PFC) and may be linked to psychiatric conditions such as schizophrenia, bipolar disorder, and addiction. We have performed a series of studies ...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章
doi:10.1073/pnas.1416196112
更新日期:2015-01-27 00:00:00
abstract::To understand complex biological systems, such as the development of multicellular organisms, it is important to characterize the gene expression dynamics. However, there is currently no universal technique for targeted insertion of reporter genes and quantitative imaging in multicellular model systems. Recently, geno...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章
doi:10.1073/pnas.1202768109
更新日期:2012-07-03 00:00:00
abstract::Inflammatory bowel diseases (IBDs), including Crohn's disease and ulcerative colitis, are associated with dysbiosis of the gut microbiome. Emerging evidence suggests that small-molecule metabolites derived from bacterial breakdown of a variety of dietary nutrients confer a wide array of host benefits, including amelio...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章
doi:10.1073/pnas.2000047117
更新日期:2020-08-11 00:00:00
abstract::Peroxisome proliferators (PP) induce a highly predictable pleiotropic response in rat and mouse liver that is characterized by hepatomegaly, increase in peroxisome number in hepatocytes, and induction of certain peroxisomal enzymes. The PP-binding protein (PPbP) was purified from rat liver cytosol by a two-step proced...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章
doi:10.1073/pnas.84.15.5242
更新日期:1987-08-01 00:00:00
abstract::Approximately 15 per cent of the light chains from homogeneous immunoglobulins in patients with multiple myeloma contain an oligosaccharide group. Five human myeloma light chains that contained carbohydrate were studied. The sequence Asn-[unk]-Ser/Thr was at the site of carbohydrate attachment in all light chains. The...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章
doi:10.1073/pnas.66.3.975
更新日期:1970-07-01 00:00:00
abstract::The soil-transmitted helminths or nematodes (hookworms, whipworms, and Ascaris) are roundworms that infect more than 1 billion of the poorest peoples and are leading causes of morbidity worldwide. Few anthelmintics are available for treatment, and only one is commonly used in mass drug administrations. New anthelminti...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章
doi:10.1073/pnas.0912327107
更新日期:2010-03-30 00:00:00
abstract::Loss-of-function mutations in the genes associated with primary microcephaly (MCPH) reduce human brain size by about two-thirds, without producing gross abnormalities in brain organization or physiology and leaving other organs largely unaffected [Woods CG, et al. (2005) Am J Hum Genet 76:717-728]. There is also evide...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章
doi:10.1073/pnas.0908454107
更新日期:2010-01-05 00:00:00
abstract::Methylmercury (MeHg) is a potent neurotoxin that is biomagnified approximately 1-10 million-fold in aquatic carnivores such as the Northern elephant seal (Mirounga angustirostris), whose excreta and molted pelage, in turn, constitute a source of environmental MeHg contamination at the base of marine food chains. The p...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章
doi:10.1073/pnas.1506520112
更新日期:2015-09-29 00:00:00
abstract::A methionine-rich low complexity (LC) domain is found within a C-terminal region of the TDP43 RNA-binding protein. Self-association of this domain leads to the formation of labile cross-β polymers and liquid-like droplets. Treatment with H2O2 caused phenomena of methionine oxidation and droplet melting that were rever...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章
doi:10.1073/pnas.2012216117
更新日期:2020-11-17 00:00:00
abstract::The objective of this study has been to determine which Na,K-ATPase isoforms are expressed in red blood cells and whether kinetic differences in the uncoupled sodium efflux mode between the human red blood cell Na,K-ATPase and other preparations can be explained by differences in the underlying subunit composition. To...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章
doi:10.1073/pnas.94.11.5943
更新日期:1997-05-27 00:00:00
abstract::Chronic hypoxia causes pulmonary hypertension with smooth muscle cell proliferation and matrix deposition in the wall of the pulmonary arterioles. We demonstrate here that hypoxia also induces a pronounced inflammation in the lung before the structural changes of the vessel wall. The proinflammatory action of hypoxia ...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章
doi:10.1073/pnas.161272598
更新日期:2001-07-17 00:00:00
abstract::We examined the MLL genomic translocation breakpoint in acute myeloid leukemia of infant twins. Southern blot analysis in both cases showed two identical MLL gene rearrangements indicating chromosomal translocation. The rearrangements were detectable in the second twin before signs of clinical disease and the intensit...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章
doi:10.1073/pnas.95.11.6413
更新日期:1998-05-26 00:00:00
abstract::A rapid and convenient method has been devised to determine the binding sites for proteins on RNA. The procedure is an adaptation of one used to map DNA-protein complexes by protection against nuclease digestion. The method uses the cytotoxic ribonuclease alpha-sarcin, which hydrolyzes purines in both single- and doub...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章
doi:10.1073/pnas.81.2.322
更新日期:1984-01-01 00:00:00
abstract::The effect of phagocytosis on lectin binding to plasma membranes of polymorphonuclear leukocytes was examined. The specific activities of binding sites of concanavalin A and Ricinus communis agglutinin (defined as mug of lectin bound per 100 mug of membrane protein) were measured on isolated membranes; they decreased ...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章
doi:10.1073/pnas.71.2.394
更新日期:1974-02-01 00:00:00
abstract::The synthesis of antiviral beta-chemokines has joined cytolysis as a potential mechanism for the control of HIV-1 infection by CD8(+) T cells. Recent evidence suggests that these two effector functions can diverge in some individuals infected with HIV-1; however, little is known about the CD8(+) T cell subsets in norm...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章
doi:10.1073/pnas.161298998
更新日期:2001-07-31 00:00:00
abstract::High levels of D-serine occur in mammalian brain, where it appears to be an endogenous ligand of the glycine site of N-methyl-D-aspartate receptors. In glial cultures of rat cerebral cortex, D-serine is enriched in type II astrocytes and is released upon stimulation with agonists of non-N-methyl-D-aspartate glutamate ...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章
doi:10.1073/pnas.96.2.721
更新日期:1999-01-19 00:00:00
abstract::Escherichia coli peptide chain release factors are proteins that direct the termination of translation in response to specific peptide chain termination codons. The mechanisms of codon recognition and peptidyl-tRNA hydrolysis are unknown. We have characterized the genes encoding release factor 1 (RF-1) and release fac...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章
doi:10.1073/pnas.82.11.3616
更新日期:1985-06-01 00:00:00
abstract::The environmental backdrop to the evolution and spread of early Homo sapiens in East Africa is known mainly from isolated outcrops and distant marine sediment cores. Here we present results from new scientific drill cores from Lake Malawi, the first long and continuous, high-fidelity records of tropical climate change...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章
doi:10.1073/pnas.0703874104
更新日期:2007-10-16 00:00:00
abstract::The mammalian hair follicle unit consists of a central follicle and a series of associated structures: sebaceous glands, arrector pili muscles, Merkel cells, and sensory nerve endings. The architecture of this multicellular structure is highly polarized with respect to the body axes. Previous work has implicated Frizz...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章
doi:10.1073/pnas.1301430110
更新日期:2013-03-05 00:00:00
abstract::Ubiquitination, the crucial posttranslational modification that regulates the eukaryotic proteome, is carried out by a trio of enzymes, known as E1 [ubiquitin (Ub)-activating enzyme], E2 (Ub-conjugating enzyme), and E3 (Ub ligase). Although most E2s can work with any of the three mechanistically distinct classes of E3...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章
doi:10.1073/pnas.1705060114
更新日期:2017-08-08 00:00:00
abstract::A screening procedure based on solvent extraction with minimal clean up followed by examination with negative chemical ionization mass spectrometry has been developed for organochlorine residues and related compounds with masses greater than 130 daltons. The procedure has been made quantitative for analysis of pentach...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章
doi:10.1073/pnas.73.6.1777
更新日期:1976-06-01 00:00:00
abstract::The Ly-6 locus encodes several cell surface proteins whose functions are unknown. Although it is hypothesized that these proteins may be receptors, there is no direct evidence that they bind a ligand. Herein we present evidence that Ly-6A.2, a Ly-6 protein expressed on T lymphocytes, binds a ligand expressed on normal...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章
doi:10.1073/pnas.92.10.4294
更新日期:1995-05-09 00:00:00
abstract::A fundamental aspect of climate change is the potential shifts in flowering phenology and pollen initiation associated with milder winters and warmer seasonal air temperature. Earlier floral anthesis has been suggested, in turn, to have a role in human disease by increasing time of exposure to pollen that causes aller...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章
doi:10.1073/pnas.1014107108
更新日期:2011-03-08 00:00:00
abstract::Cell aggregates are a tool for in vitro studies of morphogenesis, cancer invasion, and tissue engineering. They respond to mechanical forces as a complex rather than simple liquid. To change an aggregate's shape, cells have to overcome energy barriers. If cell shape fluctuations are active enough, the aggregate sponta...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章
doi:10.1073/pnas.0902085106
更新日期:2009-10-13 00:00:00
abstract::When an unusually high frequency of an allele is encountered in a population, "founder effect" is often invoked as an explanation. As usually used, the term implies the disproportionate increase through chance (rather than selection) of an allele contributed to the population by a particular ancestor. While genetic th...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章
doi:10.1073/pnas.75.3.1442
更新日期:1978-03-01 00:00:00
abstract::The lack of efficient mechanisms for stable genetic transformation of medically important insects, such as anopheline mosquitoes, is the single most important impediment to progress in identifying novel control strategies. Currently available techniques for foreign gene expression in insect cells in culture lack the b...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章
doi:10.1073/pnas.93.12.6181
更新日期:1996-06-11 00:00:00