Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: EC:6.3.4.6 (urease)
 7,490 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

A general overview is presented of the changes in the genetic expression along a time curve through the first 20 min after acidification to pH 4.5 of exponentially growing cultures of the food pathogenic strain Staphylococcus aureus 50583. A newly developed method for statistical significance testing was used to detect significant gene expression responses. Most responses showed an increase or decrease from time zero to 10 min after acidification, and then generally a stabilization in expression level from 10 to 20 min. Increased urease activity appeared to be an important factor in the acid defence, along with proton excretion by NADH dehydrogenase and macromolecule repair mechanisms. Oxidative-stress responses, such as increased expression of thioredoxin genes and upregulation of pentose phosphate pathway genes to generate more reducing power, were also induced. A general reduction in the expression of genes encoding ribosomal proteins and genes involved in nucleotide synthesis, as well as fatty acid and lipoprotein metabolism, reflected the lowered growth rate after acidification. The pH shock did not appear to trigger major virulence responses or biofilm formation. Metal ion regulation and transport were affected by the acid shock, and production of several cofactors such as molybdopterin was increased. Many of the presented observations could be explained, while some represent still-unknown mechanisms. The patterns of regulation were confirmed by quantitative reverse transcriptase PCR (QRT-PCR). Together, these results showed the main responses of S. aureus and will be a good starting point for future, more specific, in-depth studies of specific gene responses that occur in conjunction with the acid-stress defence of S. aureus.
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PMID:Acid-shock responses in Staphylococcus aureus investigated by global gene expression analysis. 1760 73

Three evergreen (Laurus nobilis, Viburnum tinus and Thuja plicata) and two autumnal abscission deciduous trees (Cydonia oblonga and Prunus domestica) have been investigated for the presence (zymogram and immunodetection) and functionality (post-illumination chlorophyll fluorescence) of the thylakoid Ndh complex. The presence of encoding ndh genes has also been investigated in T. plicata. Western assays allowed tentative identification of zymogram NADH dehydrogenase bands corresponding to the Ndh complex after native electrophoresis of solubilized fractions from L. nobilis, V. tinus, C. oblonga and P. domestica leaves, but not in those of T. plicata. However, Ndh subunits were detected after SDS-PAGE of thylakoid solubilized proteins of T. plicata. The leaves of the five plants showed the post-illumination chlorophyll fluorescence increase dependent on the presence of active Ndh complex. The fluorescence increase was higher in autumn in deciduous, but not in evergreen trees, which suggests that the thylakoid Ndh complex could be involved in autumnal leaf senescence. Two ndhB genes were sequenced from T. plicata that differ at the 350 bp 3' end sequence. Comparison with the mRNA revealed that ndhB genes have a 707-bp type II intron between exons 1 (723 bp) and 2 (729 bp) and that the UCA 259th codon is edited to UUA in mRNA. Phylogenetically, the ndhB genes of T. plicata group close to those of Metasequoia, Cryptomeria, Taxodium, Juniperus and Widdringtonia in the cupresaceae branch and are 5' end shortened by 18 codons with respect to that of angiosperms.
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PMID:Activity, polypeptide and gene identification of thylakoid Ndh complex in trees: potential physiological relevance of fluorescence assays. 2232 8