Survival of Salmonella typhimurium within macrophage phagosomes requires the coordinate expression bacterial gene products. This report examines contribution phagosomal pH as a signal for genes positively regulated by S. virulence regulators PhoP and PhoQ. Several hours after phagocytosis murine bone marrow-derived macrophages, PhoP-activated transcription increased 50- to 77-fold. In contrast, no difference in was observed infection cultured epithelial cells, suggesting that membrane sensor...

ABSTRACT In Saccharomyces cerevisiae , the rapamycin-sensitive TOR signaling pathway plays an essential role in up-regulating translation initiation and cell cycle progression response to nutrient availability. One of mechanisms by which regulates proliferation is excluding GLN3 transcriptional activator from nucleus and, consequence, preventing its activation therein. We examined possibility that cascade could also control activity Gcn4p, known respond amino acid The results presented this...

Background Gene duplication is a key evolutionary mechanism providing material for the generation of genes with new or modified functions. The fate duplicated gene copies has been amply discussed and several models have put forward to account duplicate conservation. specialization model considers that bifunctional ancestral could result in preservation both through subfunctionalization, resulting distribution two functions between duplicates. Here we investigate whether presumed character...

In this study, a set of polycationic amphiphilic cyclodextrins featuring self-assembling capabilities in the presence nucleic acids have been evaluated as therapeutic gene vectors for vivo purposes.A tetradecacationic structure incorporating 14 primary amino groups and 7 thioureido face cyclooligosaccharide core hexanoyl chains secondary was judged to be optimal delivery.This compound efficiently mediated serum-resistant transfection HeLa HepG2 cells, comparing favorably with branched...

Spinal cord injury (SCI) is an incapacitating condition that affects motor, sensory, and autonomic functions. Since 1990, the only treatment administered in acute phase of SCI has been methylprednisolone (MP), a synthetic corticosteroid anti-inflammatory effects; however, its efficacy remains controversial. Although MP thought to help resolution edema, there are no scientific grounds support this assertion. Aquaporin 4 (AQP4), most abundant component water channels CNS, participates...

Neural progenitor cells (NPCs) of the subventricular zone proliferate in response to ischemic stroke adult mouse brain. Newly generated have been considered influence recovery following a stroke. However, mechanism underlying such protection is matter active study since it has thought that proliferating NPCs mediate their protective effects by secreting soluble factors promote rather than neuronal replacement penumbra. We tested hypothesis this mediated secretion multimolecular complexes...

ABSTRACT Saccharomyces cerevisiae glutamate synthase (GOGAT) is an oligomeric enzyme composed of three 199-kDa identical subunits encoded by GLT1 . In this work, we analyzed transcriptional regulation. GLT1-lacZ fusions were prepared and expression was determined in a GDH1 wild-type strain gdh1 mutant derivative grown the presence various nitrogen sources. Null mutants impaired GCN4 , GLN3 GAT1/NIL1 or UGA43/DAL80 transformed with fusion to determine whether above-mentioned factors had role...

In the yeast Saccharomyces cerevisiae, first committed step of lysine biosynthetic pathway is catalysed by two homocitrate synthases encoded LYS20 and LYS21. We undertook a study duplicate to analyse whether their retention presumable specialization have affected efficiency biosynthesis in yeast. Our results show that during growth on ethanol, mainly synthesized through Lys21p, while under fermentative metabolism, Lys20p Lys21p play redundant roles. Furthermore, presented this paper indicate...

Background Gene duplication and the subsequent divergence of paralogous pairs play a central role in evolution novel gene functions. S. cerevisiae possesses two genes (ALT1/ALT2) which presumably encode alanine aminotransferases. It has been previously shown that Alt1 encodes an aminotransferase, involved metabolism; however physiological Alt2 is not known. Here we investigate whether ALT2 active aminotransferase. Principal Findings Our results show although ALT1 65% identical proteins, only...

Summary It is accepted that Saccharomyces cerevisiae genome arose from complete duplication of eight ancestral chromosomes; functionally normal ploidy was recovered because the massive loss 90% duplicated genes. There evidence indicates part this selective conservation gene pairs compelling to yeast facultative metabolism. As an example, NADP‐glutamate dehydrogenase pathway has been maintained differential expression paralogous GDH1 and GDH3 genes, biochemical specialization enzymes they...

The transcriptional activation response relies on a repertoire of activators, which decipher regulatory information through their specific binding to cognate sequences, and capacity selectively recruit the components that constitute given complex. We have addressed possibility achieving novel responses by construction new regulator--the Hap2-3-5-Gln3 hybrid modulator--harbouring HAP complex polypeptides DNA-binding domain (Hap2-3-5) Gln3 domain, usually act in an uncombined fashion. results...

Summary Transcription of an important number divergent genes Saccharomyces cerevisiae is controlled by intergenic regions, which constitute factual bidirectional promoters. However, few such promoters have been characterized in detail. The analysis the UGA3‐GLT1 region has provided interesting model to study joint action two global transcriptional activators that had considered act independently. Our results show Gln3p and Gcn4p exert their effect upon cis ‐acting elements, are shared a...

Summary: The activities of the enzymes involved in ammonium assimilation and glutamate biosynthesis were determined wild-type NADP-glutamate dehydrogenase (GDH) null mutant strains Kluyveromyces lactis. specific NADP-GDH activity from K. lactis was fivefold lower than that found Saccharomyces cerevisiae. glutamine synthetase (GS) synthase (GOGAT) similar to those reported S. obtained by transforming uraA strain MD2/1 with a linearized integrative yeast vector harbouring 390 bp fragment...

Purified glutamate synthase (GOGAT) from Kluyveromyces lactis was characterized as a high-molecular-mass polypeptide, distinction shared with previously described GOGATs other eukaryotic micro-organisms. Using degenerate deoxyoligonucleotides, designed conserved regions of the alfalfa, maize and Escherichia coli GOGAT genes, 300 bp PCR fragment K. gene KlGLT1 obtained. This used to construct null mutants by replacement. These showed no growth defect phenotype were able grow on ammonium sole...

The phenotypic characterization of a Saccharomyces cerevisiae mutant unable to grow under agitated conditions is presented here. When this strain was incubated aerobic conditions, it did not and the viability culture decreased. loss in prevented by addition antioxidants or chelating agents medium, indicating that withstand oxidative stress generated metabolism. This complemented with plasmids from yeast genomic library. transformants were obtained carried harbouring TYR1 gene, which codes...

Summary A Saccharomyces cerevisiae glutamate auxotroph, lacking NADP‐glutamate dehydrogenase (NADP‐GDH) and synthase (GOGAT) activities, was complemented with a yeast genomic library. Clones were obtained which still lacked NADP‐GDH but showed GOGAT activity. Northern analysis revealed that the DNA fragment present in complementing plasmids coded for 1.5kb mRNA. Since only enzyme so far purified from S. is made up of small large subunit, size mRNA suggested cloned could code subunit....