Search results for "script"
showing 10 items of 5143 documents
A Gene-Specific Requirement for FACT during Transcription Is Related to the Chromatin Organization of the Transcribed Region
2006
The FACT complex stimulates transcription elongation on nucleosomal templates. In vivo experiments also involve FACT in the reassembly of nucleosomes traversed by RNA polymerase II. Since several features of chromatin organization vary throughout the genome, we wondered whether FACT is equally required for all genes. We show in this study that the in vivo depletion of Spt16, one of the subunits of Saccharomyces cerevisiae FACT, strongly affects transcription of three genes, GAL1, PHO5, and Kluyveromyces lactis LAC4, which exhibit positioned nucleosomes at their transcribed regions. In contrast, showing a random nucleosome structure, YAT1 and Escherichia coli lacZ are only mildly influenced …
Parkin and relatives: the RBR family of ubiquitin ligases
2004
Mutations in the parkin gene cause autosomal-recessive juvenile parkinsonism. Parkin encodes a ubiquitinprotein ligase characterized by having the RBR domain, composed of two RING fingers plus an IBR/DRIL domain. The RBR family is defined as the group of genes whose products contain an RBR domain. RBR family members exist in all eukaryotic species for which significant sequence data is available, including animals, plants, fungi, and several protists. The integration of comparative genomics with structural and functional data allows us to conclude that RBR proteins have multiple roles, not only in protein quality control mechanisms, but also as indirect regulators of transcription. A recent…
Further characterization of the histidine gene cluster of Streptomyces coelicolor A3(2): nucleotide sequence and transcriptional analysis of hisD.
1992
We have further characterized the genomic region of Streptomyces coelicolor A3(2) that contains genes involved in the biosynthesis of histidine. A 2,357-base pair fragment contained in plasmid pSCH3328 that complemented hisD mutations has been sequenced. Computer analysis revealed an open reading frame that encodes a protein with significant homology to the Escherichia coli, Salmonella typhimurium and Mycobacterium smegmatis hisD product, Saccharomyces cerevisiae HIS4C, and Neurospora crassa his3 gene products. Two other contiguous open reading frames oriented divergently with respect to hisD did not show significant similarity with any of the his genes or to other sequences included in the…
BRG1 and NRG1 form a novel feedback circuit regulating Candida albicans hypha formation and virulence
2012
In the opportunistic fungal pathogen Candida albicans both cellular morphology and the capacity to cause disease are regulated by the transcriptional repressor Nrg1p. One of the genes repressed by Nrg1p is BRG1, which encodes a putative GATA family transcription factor. Deletion of both copies of this gene prevents hypha formation. We discovered that BRG1 over-expression is sufficient to overcome Nrg1p-mediated repression and drive the morphogenetic shift from yeast to hyphae even in the absence of environmental stimuli. We further observed that expression of BRG1 influences the stability of the NRG1 transcript, thus controlling filamentation through a feedback loop. Analysis of this phenom…
Prion infected rhesus monkeys to study differential transcription of Alu DNA elements and editing of Alu transcripts in neuronal cells and blood cells
2012
Background Rhesus monkeys were used as a non-human primate model to study small non-coding RNA after infection with human sporadic and variant Creutzfeldt–Jakob prions. Methods Tissue-specific Alu DNA element transcription and editing of transcripts were assessed in neuronal – and blood cells (Buffy Coat). Results Tissue/cell-specific transcription and editing patterns were obtained. Active Alu DNA elements belonged to several Alu DNA families, they could be located on several chromosomes, and their genomic sites were identified. Deamination by adenosine deaminase acting on RNA and apolipoprotein B editing complex was found. Conclusions Different Alu transcription and editing programmes…
Interactions between DNA damage, repair, and transcription
2010
This review addresses a variety of mechanisms by which DNA repair interacts with transcription and vice versa. Blocking of transcriptional elongation is the best studied of these mechanisms. Transcription recovery after damage therefore has often been used as a surrogate marker of DNA repair in cells. However, it has become evident that relationships between DNA damage, repair, and transcription are more complex due to various indirect effects of DNA damage on gene transcription. These include inhibition of transcription by DNA repair intermediates as well as regulation of transcription and of the epigenetic status of the genes by DNA repair-related mechanisms. In addition, since transcript…
Differential expression of SUC genes: A question of bases
1994
Non-coding nucleotide sequences located 5' upstream of the transcriptional start site play an essential role in gene expression as they contain binding sites for transcription and regulatory factors. The yeast SUC gene family is a useful model to study the influence that nucleotide exchanges within the promoter regions have on their expression, since (i) these genes, regulated by glucose repression, are differentially transcribed (invertase activity produced by distinct SUC genes may show variations of about 10-fold); and (ii) promoter sequences of SUC3, SUC4, SUC5 and SUC7 are more than 99% homologous, showing only six base exchanges among all of them. Comparison of these nucleotide exchan…
The Conserved Foot Domain of RNA Pol II Associates with Proteins Involved in Transcriptional Initiation and/or Early Elongation
2011
RNA polymerase (pol) II establishes many protein-protein interactions with transcriptional regulators to coordinate different steps of transcription. Although some of these interactions have been well described, little is known about the existence of RNA pol II regions involved in contact with transcriptional regulators. We hypothesize that conserved regions on the surface of RNA pol II contact transcriptional regulators. We identified such an RNA pol II conserved region that includes the majority of the >foot> domain and identified interactions of this region with Mvp1, a protein required for sorting proteins to the vacuole, and Spo14, a phospholipase D. Deletion of MVP1 and SPO14 affects …
Mutational analysis of eggplant latent viroid RNA processing in Chlamydomonas reinhardtii chloroplast.
2009
Viroids of the family Avsunviroidae, such as eggplant latent viroid (ELVd), contain hammerhead ribozymes and replicate in the chloroplasts of the host plant through an RNA-based symmetrical rolling-circle mechanism in which oligomeric RNAs of both polarity are processed to monomeric linear RNAs (by cleavage) and to monomeric circular RNAs (by ligation). Using an experimental system consisting of transplastomic lines of the alga Chlamydomonas reinhardtii, a mutational analysis of sequence and structural elements in the ELVd molecule that are involved in transcript processing in vivo in a chloroplastic context was carried out. A collection of six insertion and three deletion ELVd mutants was …
Transcriptomic Signature of Trophoblast Differentiation in a Human Embryonic Stem Cell Model1
2011
Identification of genes involved in trophoblast differentiation is of great interest in understanding cellular and molecular mechanisms involved in placental development and is relevant clinically to fetal development, fertility, and maternal health. Herein, we investigated differentiation of human embryonic stem cells (hESCs) down the trophoblast lineage by culture with bone morphogenetic protein 4 (BMP4) over a 10-day period. Within 2 days, the stemness markers POU5F1 and NANOG were markedly down-regulated, followed temporally by up-regulation of the CDX2, KRT7, HLA-G, ID2, CGA, and CGB trophoblast markers. To understand, on a global scale, changes in the transcriptome during the differen…