Search results for " transcription"

TGFbeta regulates the CD4+CD25+ T-cell pool and the expression of Foxp3 in vivo.

2004

Factors influencing the development of CD4+CD25+ T-cells in vivo are poorly understood. In order to investigate the contribution of TGFbeta1 to the development and function of CD4+CD25+ T-cells, we generated a gain of function mutation resulting in the overexpression of an active form of TGFbeta1 in T-cells under control of the human CD2 promoter. In peripheral lymphoid organs and in the thymus, the frequency of CD4+CD25+ T-cells was increased in transgenic mice. This appeared to be due to an autocrine effect of TGFbeta on T-cells, since concomitant impairment of TGFbeta-signaling in double transgenic mice resulted in a phenotype similar to wild type. In contrast, in single transgenic mice …

The cis-regulatory sequences required for expression of the Drosophila melanogaster adult cuticle gene ACP65A.

2009

Post-embryonic development in insects requires successive molts. Molts are triggered by ecdysteroids, and the nature of the molt (larval, pupal or adult) is determined by juvenile hormones. The genes encoding cuticle proteins are targets of both classes of hormones, and therefore are interesting models to study hormone action at the molecular level. The Drosophila ACP65A cuticle gene is expressed exclusively during the synthesis of the adult exoskeleton, in epidermal domains synthesising flexible cuticle. We have examined the cis -regulatory sequences of ACP65A using phylogenetic comparisons and functional analysis, and find that only about 180 bp are essential, including an 81 bp intron. T…

In silico characterization of LZTS3, a potential tumor suppressor

2005

Members of the leucine zipper tumor suppressor (LZTS) protein family are thought to play roles in cell growth modulation. The two currently known members were identified by analyzing genomic and chromosomal alterations reported to be either involved or deleted in various types of cancer, suggesting a causative relationship. By means of computational biology, we have now identified a novel member of the LZTS protein family named LZTS3. The corresponding gene was localized to chromosome 20p13 and consisted of three exons. The novel LZTS3 protein demonstrated a high similarity to LAPSER1/LZTS2 and FEZ1/LZTS1, two members of the LZTS family. The conserved FEZ1 domain contains a leucine zipper m…

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…

Genetic and phenotypic heterogeneity in two novel cases of Waardenburg syndrome type IV.

2009

Murine Cytomegalovirus Major Immediate-Early Enhancer Region Operating as a Genetic Switch in Bidirectional Gene Pair Transcription

2007

ABSTRACT Enhancers are defined as DNA elements that increase transcription when placed in any orientation relative to a promoter. The major immediate-early (MIE) enhancer region of murine cytomegalovirus is flanked by transcription units ie1/3 and ie2 , which are transcribed in opposite directions. We have addressed the fundamental mechanistic question of whether the enhancer synchronizes transcription of the bidirectional gene pair (synchronizer model) or whether it operates as a genetic switch, enhancing transcription of either gene in a stochastic alternation (switch model). Clonal analysis of cytokine-triggered, transcription factor-mediated MIE gene expression from latent viral genomes…

RB1 in cancer: Different mechanisms of RB1 inactivation and alterations of pRb pathway in tumorigenesis

2013

Loss of RB1 gene is considered either a causal or an accelerating event in retinoblastoma. A variety of mechanisms inactivates RB1 gene, including intragenic mutations, loss of expression by methylation and chromosomal deletions, with effects which are species-and cell type-specific. RB1 deletion can even lead to aneuploidy thus greatly increasing cancer risk. The RB1gene is part of a larger gene family that includes RBL1 and RBL2, each of the three encoding structurally related proteins indicated as pRb, p107, and p130, respectively. The great interest in these genes and proteins springs from their ability to slow down neoplastic growth. pRb can associate with various proteins by which it …

Polymorphism and chromosomal localization of the porcine signal transducer and activator of transcription 5B gene (STAT5B).

2006

Signal transducers and activators of transcription (STATs) are a family of transcription factors. STAT5A and 5B are two highly related proteins encoded by two distinct genes. Transgenic knockout mice studies have indicated the importance of STAT5 proteins for the regulation of both lactation and growth performance. Moreover, different studies determine the role of STAT5 proteins in the modulation of adipocyte function. In this study, we sequenced one fragment of STAT5B gene from animals of six breeds (Duroc, Iberian, Landrace, Large White, Pie´train and Meishan) to identify genetic variants. A G/A single nucleotide polymorphism in intron 14 creates a polymorphic PstI restriction site and wa…

Assignment of signal transducer and activator of transcription 5A (STAT5A) to porcine chromosome 12p13→p11 by radiation hybrid panel mapping

2005

What do you mean by transcription rate?

2013

mRNA synthesis in all organisms is performed by RNA polymerases, which work as nanomachines on DNA templates. The rate at which their product is made is an important parameter in gene expression. Transcription rate encompasses two related, yet different, concepts: the nascent transcription rate, which measures the in situ mRNA production by RNA polymerase, and the rate of synthesis of mature mRNA, which measures the contribution of transcription to the mRNA concentration. Both parameters are useful for molecular biologists, but they are not interchangeable and they are expressed in different units. It is important to distinguish when and where each one should be used. We propose that for fu…