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The mouse delta‐like homolog 1 and type III iodothyronine deiodinase (Dlk1–Dio3) imprinted domain contains three known paternally methylated differentially methylated regions (DMRs): intergenic DMR (IG‐DMR), maternally expressed 3‐DMR (Gtl2‐DMR), and Dlk1‐DMR. Here, we report the first maternally methylated DMR, CpG island 2 (CGI‐2), is located approximately 800 bp downstream of miR‐1188. CGI‐2 is highly methylated in sperm and oocytes, de‐methylated in pre‐implantation embryos, and differentially re‐methylated during post‐implantation development. CGI‐2, similarly to Gtl2‐DMR and Dlk1‐DMR, acquires differential methylation prior to embryonic day 7.5 (E7.5). Both H3K4me3 and H3K9me3 histone modifications are enriched at CGI‐2. Furthermore, CCCTC‐binding factor (CTCF) binds to both alleles of CGI‐2 in vivo. These results contribute to the investigation of imprinting regulation in this domain.CGI‐2 is the first maternally methylated DMR found in the Dlk1–Dio3 domain. CGI‐2 undergoes a complex demethylation and re‐methylation process in pre‐ and post‐implantation embryos. CGI‐2 acquires differential methylation at around the same time as Gtl2‐DMR and Dlk1‐DMR. CTCF binds to CGI‐2 in vivo. [ABSTRACT FROM AUTHOR]

Abstract: REST/NRSF (the RE-1 silencing transcription factor or neuron-restrictive silencer factor) was originally identified as a transcriptional repressor of a number of neuronal-specific genes in neural stem cells and non-neuronal cells. REST functions as a master regulator in the maintenance of neural stem cells. During tumorigenesis, REST shows opposing roles in different type of cells. In human epithelial cancers such as colon cancer, REST acts as a tumor suppressor. In contrast, REST plays an oncogenic role in the development of brain tumors and other cancers. Abnormal upregulation of REST has been found in medulloblastoma, neuroblastoma and glioblastoma (GBM). Recent studies in GBMs suggest that REST exerts its oncogenic function by maintaining self-renewal potential of glioma stem cells (GSCs). [Copyright &y& Elsevier]

Abstract: In this study we showed that the dengue virus (DENV) core protein forms a dimer with an α-helix-rich structure, binds RNA and facilitates the strand annealing process. To assess the RNA chaperone activity of this core protein and other dengue viral RNA-interacting proteins, such as NS3 helicase and NS5 proteins, we engineered cis- and trans-cleavage hammerhead ribozyme constructs carrying DENV genomic RNA elements. Our results indicate that DENV core protein facilitates typical hammerhead structure formation by acting as an RNA chaperone and DENV NS5 has a weak RNA chaperone activity, while DENV NS3 helicase failed to refold RNA with a complex secondary structure. [Copyright &y& Elsevier]

Abstract: NS3H, the helicase domain of HCV NS3, possesses RNA-stimulated ATPase and ATP hydrolysis-dependent dsRNA unwinding activities. Here, the ability of NS3H to facilitate RNA structural rearrangement is studied using relatively long RNA strands as the model substrates. NS3H promotes intermolecular annealing, resolves three-stranded RNA duplexes, and assists dsRNA and ssRNA inter-conversions to establish a steady state among RNA structures. NS3H facilitates RNA structure conversions in a mode distinct from an ATP-independent RNA chaperone. These findings expand the known function of HCV NS3 helicase and reveal a role for viral helicase in assisting RNA structure conversions during virus life cycle. [Copyright &y& Elsevier]

Abstract: The helicase domain of dengue virus NS3 protein (DENV NS3H) contains RNA-stimulated nucleoside triphosphatase (NTPase), ATPase/helicase, and RNA 5′-triphosphatase (RTPase) activities that are essential for viral RNA replication and capping. Here, we show that DENV NS3H unwinds 3′-tailed duplex with an RNA but not a DNA loading strand, and the helicase activity is poorly processive. The substrate of the divalent cation-dependent RTPase activity is not restricted to viral RNA 5′-terminus, a protruding 5′-terminus made the RNA 5′-triphosphate readily accessible to DENV NS3H. DENV NS3H preferentially binds RNA to DNA, and the functional interaction with RNA is sensitive to ionic strength. [Copyright &y& Elsevier]

Abstract: We used synthetic DNA oligos to investigate the nucleic acid chaperone properties of the N terminal domain of hepatitis delta antigen (NdAg). We found that NdAg possessed a bona fide chaperone activity. NdAg could distinguish subtle differences in the thermal stability of the base pairing region, and enabled DNA oligos to form a more stable duplex among competing sequences through facilitating strand annealing selectively, stimulating duplex conversion selectively, and stabilizing the more stable duplex. The property of NdAg identified in this study could be applied to improve the efficiency and specificity of dot blot hybridization under conditions of low stringency. [Copyright &y& Elsevier]