Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UNIPROT:P62988 (Ubiquitin)
 4,326 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Carbon and nitrogen regulation of UBI4, the stress-inducible polyubiquitin gene of Saccharomyces cerevisiae, was investigated using a UBI4 promoter-LacZ fusion gene (UBI4-LacZ). Expression of this gene in cells grown on different media indicated that the UBI4 promoter is more active during growth on respiratory than on fermentable carbon sources but is not subject to appreciable control by nitrogen catabolite repression. UBI4-LacZ expression was virtually identical in cells having constitutively high (ras2, sra1-13) or constitutively low (ras2) levels of cyclic AMP-dependent protein kinase activity, indicating that this kinase does not exert a major influence on UBI4 expression. Catabolite derepression control of the UBI4 promoter was confirmed by measurements of UBI4-LacZ expression in hap mutant and wild-type strains before and after transfer from glucose to lactate. Mutagenesis of the perfect consensus for HAP2/3/4 complex binding at position -542 resulted in considerable reduction of UBI4 promoter derepression with respiratory adaptation in HAP wild-type cells and abolished the reduced UBI4-LacZ derepression normally seen when aerobic cultures of the hap1 mutant are transferred from glucose to lactate. This HAP2/3/4 binding site is therefore a major element contributing to catabolite derepression of the UBI4 promoter, although data obtained with hapl mutant cells indicated that HAP1 also contributes to this derepression. The HAP2/3/4 and HAP1 systems are normally found to activate genes for mitochondrial (respiratory) functions. Their involvement in mediating higher activity of the UBI4 promoter during respiratory growth may reflect the contribution of UBI4 expression to tolerance of oxidative stress.
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PMID:UBI4, the polyubiquitin gene of Saccharomyces cerevisiae, is a heat shock gene that is also subject to catabolite derepression control. 903 3

Protein backbone (15)N spin relaxation rates measured by solution NMR provide useful dynamic information with a site-specific resolution. The conventional method is to record a series of 2D (1)H-(15)N HSQC spectra with varied relaxation delays, and derive relaxation rate from the following curve fitting on the resonance intensities. Proteins with poorly resolved spectra often require several 3D HNCO spectra to be collected on a (15)N/(13)C double labeled protein sample. In order to reduce the relaxation dimension Carr et al. (P.A. Carr, D.A. Fearing, A.G. Palmer, 3D accordion spectroscopy for measuring N-15 and (CO)-Carbon-13 relaxation rates in poorly resolved NMR spectra, J. Magn. Reson. 132 (1998) 25-33) employed an Accordion type HNCO pulse sequence to obtain (15)N or (13)C T(1) relaxation rates by numerical fitting of the relaxation interfered free induction decay (FID) data. To avoid intensive analysis of the time domain data, we propose a modified protocol to measure (15)N T(1) and T(2) relaxation rates from easily obtained line-widths in an Accordion HNCO spectrum. Both T(1) and T(2) relaxation could be simultaneously convoluted into the constant-time evolution periods of (13)C' and (15)N, respectively. The relaxation delay was allowed to reach at least 3 x T(1) or 3 x T(2) so that the signal was substantially decayed by the end of the FID, and the resulting peak full-width at half height (FWHH) could be directly used to calculate relaxation rate. When applied to the 76-residue Ubiquitin and the 226-residue glutamine-binding protein (GlnBP), this method yielded T(1) and T(2) values deviating on average by 4-6% and 5-7%, respectively, from the measurements based on the conventional 2D method. In comparison, the conventional methods possessed intrinsic error ranges of 2-4% for T(1) and 3-6% for T(2). In addition to comparable accuracy, the fully-relaxed Accordion HNCO method presented here allowed measurements of relaxation rates for resonances unresolved in 2D spectra, thus providing a more complete dynamic picture of the protein.
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PMID:Direct measurements of protein backbone 15N spin relaxation rates from peak line-width using a fully-relaxed Accordion 3D HNCO experiment. 1911 14

High temperature stress has become a major concern for crop production worldwide because it greatly affects the growth, development, and productivity of plants. The mechanisms underlying the development of heat-tolerance need to be better understood for important agricultural crops. Recent research shows that DNA methylation is dynamic during plant development. However, the molecular mechanism regulating these dynamic DNA methylation patterns remains to be elucidated. In this study, six MethylRAD libraries were constructed using DNA isolated from leaves of maize. A total of 42,561,144 and 48,157,284 clean reads were generated from CK (Control condition) and HTP (Heat stress condition) treatments, respectively. The results showed that a total of 25,470 methylated genes were found in six tested samples, including 325 differentially methylated genes (200 in CCGG sites and 125 in CCWGG sites) between the CK and HTP samples. KEGG pathway enrichment analysis for DMGs indicated that Spliceosome, Homologous recombination, RNA transport, Ubiquitin mediated proteolysis and Carbon metabolism pathways play a central role in maize response to heat stress. Taken together, this research revealed the genome-wide DNA methylation pattern of maize leaves in response to heat exposure and identified candidate genes potentially involved in response to heat stress at the methylation level, which will facilitate future studies to elucidate the epigenetic mechanisms underlying the responses of maize to heat stress.
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PMID:The Dynamics of DNA methylation in the maize (Zea mays L.) inbred line B73 response to heat stress at the seedling stage. 3092 68