Search results for "LONG"

External conditions inversely change the RNA polymerase II elongation rate and density in yeast.

2013

Elongation speed is a key parameter in RNA polymerase II (RNA pol II) activity. It affects the transcription rate, while it is conditioned by the physicochemical environment it works in at the same time. For instance, it is well-known that temperature affects the biochemical reactions rates. Therefore in free-living organisms that are able to grow at various environmental temperatures, such as the yeast Saccharomyces cerevisiae, evolution should have not only shaped the structural and functional properties of this key enzyme, but should have also provided mechanisms and pathways to adapt its activity to the optimal performance required. We studied the changes in RNA pol II elongation speed …

NFAT transcription factors control HIV-1 expression through a binding site downstream of TAR region.

2004

NFAT factors control HIV-1 transcription. We show here that, in addition to binding to two NF-kappaB/NFAT sites within the U3 HIV LTR, NFATc1 and NFATc2 bind to an NFAT site within the LTR's U5 region. Mutations in this site which abolish NFAT binding reduce the ability of NFATs to transactivate LTR-mediated transcription. Mutations in all three NFAT sites strongly interfered with LTR induction, but affected moderately the stimulatory effect of Tat.

RNA memory model: a RNA-mediated transcriptional activation mechanism involved in cell identity.

2010

Position-effect variegation (PEV) was discovered in Drosophila melanogaster in 1930 in a study of X-ray-induced chromosomal rearrangements. If a rearrangement places euchromatic genes adjacent to a region of centromeric heterochromatin, it gives a variegated phenotype that results from the random inactivation of genes by heterochromatin spreading from the breakpoint. After the establishment, the inactivation is henceforth clonally inherited. The vast majority of these modifiers were originally isolated in Drosophila as dominant mutations that suppressed or enhanced the variegation caused by a variegating white allele called white-mottled 4 (wm4). A large number of modifier genes alter PEV p…

Plasmid conjugation from Proteobacteria as evidence for the origin of xenologous genes in Cyanobacteria

2014

Comparative genomics have shown that 5% of Synechococcus elongatus PCC 7942 genes are of probable proteobacterial origin. To investigate the role of interphylum conjugation in cyanobacterial gene acquisition, we tested the ability of a set of prototype proteobacterial conjugative plasmids (RP4, pKM101, R388, R64, and F) to transfer DNA from Escherichia coli to S. elongatus. A series of BioBrick-compatible, mobilizable shuttle vectors was developed. These vectors were based on the putative origin of replication of the Synechococcus resident plasmid pANL. Not only broad-host-range plasmids, such as RP4 and R388, but also narrower-host-range plasmids, such as pKM101, all encoding MPFT-type IV …

Overexpression of Human and Fly Frataxins in Drosophila Provokes Deleterious Effects at Biochemical, Physiological and Developmental Levels

2011

10 pages, 5 figures. 21779322[PubMed] PMCID: PMC3136927

Noisy dynamics in long and short Josephson junctions

The study of nonlinear dynamics in long Josephson junctions and the features of a particular kind of junction realized using a graphene layer, are the main topics of this research work. The superconducting state of a Josephson junction is a metastable state, and the switching to the resistive state is directly related to characteristic macroscopic quantities, such as the current the voltage across the junction, and the magnetic field through it. Noise sources can affect the mean lifetime of this superconducting metastable state, so that noise induced effects on the transient dynamics of these systems should be taken into account. The long Josephson junctions are investigated in the sine-Gor…

Fertility and Polarized Cell Growth Depends on eIF5A for Translation of Polyproline-Rich Formins in Saccharomyces cerevisiae

2014

eIF5A is an essential and evolutionary conserved translation elongation factor, which has recently been proposed to be required for the translation of proteins with consecutive prolines. The binding of eIF5A to ribosomes occurs upon its activation by hypusination, a modification that requires spermidine, an essential factor for mammalian fertility that also promotes yeast mating. We show that in response to pheromone, hypusinated eIF5A is required for shmoo formation, localization of polarisome components, induction of cell fusion proteins, and actin assembly in yeast. We also show that eIF5A is required for the translation of Bni1, a proline-rich formin involved in polarized growth during …

FP187MITOCHONDRIAL DYSFUNCTION INDUCED BY TENOFOVIR IN RENAL CELLS. POTENTIATION OF THE EFFECTS BY CO-STIMULATION WITH ANGIOTENSIN II

2015

Structural and evolutionary analysis of the copia-like elements in the Arabidopsis thaliana genome.

2001

The analysis of 460 kb of genomic sequence of Arabidopsis thaliana chromosome III allowed us to identify two new transposable elements named AtC1 and AtC2. AtC1 shows identical long terminal repeats (LTRs) and all the structural features characteristic of the copia-like active elements. AtC2 is also a full copia-like element, but a putative stop codon in the open reading frame (ORF) would produce a truncated protein. In order to identify the copia-like fraction of the A. thaliana genome, a careful computer-based analysis of the available sequences (which correspond to 92% of the genome) was performed. Approximately 300 nonredundant copia-like sequences homologous to AtC1 and AtC2 were detec…

The Norway spruce genome sequence and conifer genome evolution

2013

Conifers have dominated forests for more than 200 million years and are of huge ecological and economic importance. Here we present the draft assembly of the 20-gigabase genome of Norway spruce (Picea abies), the first available for any gymnosperm. The number of well-supported genes (28,354) is similar to the >100 times smaller genome of Arabidopsis thaliana, and there is no evidence of a recent whole-genome duplication in the gymnosperm lineage. Instead, the large genome size seems to result from the slow and steady accumulation of a diverse set of long-terminal repeat transposable elements, possibly owing to the lack of an efficient elimination mechanism. Comparative sequencing of Pinu…