Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: EC:3.1.31.1 (micrococcal nuclease)
 2,818 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

We investigated the separation and detection of the 5'-monophosphates of 2'-deoxynucleosides selectively conjugated with 4,4-difluoro-5,7-dimethyl-4-bora-3a,4a-diaza-s-indacene-3-propionyl ethylene diamine hydrochloride (BODIPY FL EDA) at the 5'-phosphate group using capillary electrophoresis with laser-induced fluorescence detection (CE-LIF). BODIPY conjugates of the four common deoxynucleoside-5'-monophosphates (2'-deoxyguanosine-5'-monophosphate, 2'-deoxyadenosine-5'-monophosphate, 2'-deoxycytidine-5'-monophosphate, and thymidine-5'-monophosphate) were prepared and subjected to CE-LIF to serve as standard compounds for peak assignment and to develop separation conditions for the analysis of DNA. BODIPY conjugates were detected and resolved by CE-LIF after digestion of DNA or an oligonucleotide to 5'-monophosphates by nuclease P1 (NP 1) and fluorescence labeling without further purification step. Comparative analyses of calf-thymus DNA digested either with micrococcal nuclease/spleen phosphodiesterase to 3'-monophosphates or with NP 1 to 5'-monophosphates showed that both versions of the fluorescence postlabeling assay were equally efficient and sensitive. Moreover, using the same assay, 2'-deoxyuridine and 2'-deoxy-5methylcytidine were identified in bisulfite treated DNA after NP 1 digestion indicating that fluorescence postlabeling of 2'-deoxyribonucleoside-5'-monophosphates with BODIPY FL EDA and detection by CE-LIF has the potential to determine DNA damage and genomic DNA methylation.
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PMID:Detection and separation of nucleoside-5'-monophosphates of DNA by conjugation with the fluorescent dye BODIPY and capillary electrophoresis with laser-induced fluorescence detection. 1593 55

DNA demethylation of astrocyte-specific gene promoters and STAT3 activation in neural precursor cells (NPCs) are essential for astrogliogenesis in the developing brain. To date, it remains unclear whether DNA methylation is the sole epigenetic determinant responsible for suppressing astrocyte-specific genes. Here, we used mouse embryonic stem cells (TKO ESCs) that lacked all 3 DNA methyltransferase genes, Dnmt1, Dnmt3a, and Dnmt3b, and thereby exhibit complete demethylation of the astrocyte-specific glial fibrillary acidic protein (Gfap) gene promoter. We found that although the Gfap promoter was demethylated, STAT3 failed to bind to its cognate element to induce Gfap transcription, whereas it induced transcription of a different target gene, Socs3. Moreover, although the Gfap promoter region containing the STAT3-binding site (GSBS) is enriched with transcription-repressive histone modifications, such as methylation of H3 at lysine 9 (H3K9me3) and H3K27me3, the reduction of these modifications in TKO ESCs was not sufficient for binding of STAT3 at GSBS. Furthermore, GSBS was digested by micrococcal nuclease in late-gestational NPCs that express GFAP upon LIF stimulation, but not in cells that show no expression of GFAP even in the presence of LIF, indicating that STAT3 can access GSBS in the former cells. We further showed that expression of NF-1A, which is known to potentiate differentiation of mid-gestational NPCs into astrocytes, increased its accessibility. Taken together, our results suggest that chromatin accessibility of GSBS plays a critical role in the regulation of Gfap expression.
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PMID:Chromatin accessibility at a STAT3 target site is altered prior to astrocyte differentiation. 2343 58