Persistent infections of hepatitis C virus (HCV) are known to be a major risk factor for causing hepatocellular carcinomas. Nonstructural protein 3 (NS3) of HCV has serine protease and RNA helicase domains, and is essential for the viral replication. Further, NS3 is also considered to be involved in the development of HCV-induced hepatocellular carcinomas. In this report, we focus on the functi...

It has been assumed that constitutive and regulated splicing of RNA polymerase II transcripts depends exclusively on signals present in the RNA molecule. Here we show that changes in promoter structure strongly affect splice site selection. We investigated the splicing of the ED I exon, which encodes a facultative type III repeat of fibronectin, whose inclusion is regulated during development a...

Background: Gene silencing mediated by small interfering RNA (siRNA) has become a powerful biological tool for the regulation of gene expression. For the synthesis of siRNA by vector-based expression systems, several mammalian small nuclear RNA (snRNA) promoters have been cloned and shown different transcriptional efficiencies. Results: In this study, we identified a sheep 7SK snRNA (s7SK) prom...

Chromatin insulators are regulatory elements involved in the modulation of enhancer-promoter communication. The 1A2 and Wari insulators are located immediately downstream of the Drosophila yellow and white genes, respectively. Using an assay based on the yeast GAL4 activator, we have found that both insulators are able to interact with their target promoters in transgenic lines, forming gene lo...

Chemokine C-X-C motif ligand 12 (CXCL12) is a potent chemotactic and angiogenic factor that has been proposed to play a role in organ-specific metastasis and angiogenic activity in several malignancies. In this study, we found that the overexpression of c-myb could elevate CXCL12 mRNA level and CXCL12 promoter activity in human T47D and MCF-7 breast cancer cells. Chromatin immunoprecipitation a...

CXC chemokine receptor 4 (CXCR4) is a cell surface receptor that has been shown to mediate the metastasis of many solid tumors including lung, breast, kidney, and prostate tumors. In this study, we found that overexpression of ets variant gene 4 (PEA3) could elevate CXCR4 mRNA level and CXCR4 promoter activity in human MDA-MB-231 and MCF-7 breast cancer cells. PEA3 promoted CXCR4 expression and...

The cRNA promoter of Thogoto virus, a tick-borne orthomyxovirus, was investigated using an in vitro polymerase assay based on purified viral cores and synthetic oligoribonucleotides corresponding to the 3' and 5' ends of cRNA. In vitro polymerase activity relied on an interaction between the 3' and 5' ends of cRNA and was ApG primer-dependent. Mutational analysis of the promoter showed that int...

Statins are 3-hydroxy-3-methylglutaryl-CoA reductase inhibitors broadly used for the control of hypercholesterolemia. Recently, they are reported to have beneficial effects on certain cancers. In this study, we show that statins inhibited the histone deacetylase (HDAC) activity and increased the accumulation of acetylated histone-H3 and the expression of p21 in human cancer cells. Computational...

Gene expression is highly controlled and regulated in living cells. One of the first steps in gene transcription is recognition of the promoter site by the TATA box Binding Protein (TBP). TBP recruits other transcriptions factors and eventually the RNA polymerase II to transcribe the DNA in mRNA. We developed a single pair Förster Resonance Energy Transfer (spFRET) assay to investigate the mech...

Leaf senescence in plants involves both positive and negative transcriptional regulation. In this work, we show evidence for the single-stranded DNA-binding protein WHIRLY1 (WHY1) that functions as an upstream suppressor of WRKY53 in a developmental stage-dependent manner during leaf senescence in Arabidopsis (Arabidopsis thaliana). The why1 mutant displayed an early-senescence phenotype. In th...