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641.
Saleem M Brim H Hussain S Arshad M Leigh MB Zia-ul-Hassan 《Biotechnology advances》2008,26(2):151-161
The display of heterologous proteins on the microbial cell surface by means of recombinant DNA biotechnologies has emerged as a novel approach for bioremediation of contaminated sites. Both bacteria and yeasts have been investigated for this purpose. Cell surface expression of specific proteins allows the engineered microorganisms to transport, bio-accumulate and/or detoxify heavy metals as well as to degrade xenobiotics. These otherwise would not be taken up and transformed by the microbial cell. This review focuses on the application of cell surface displays for the enhanced bio-accumulation of heavy metals by metal binding proteins. It also reviews the biodegradation of xenobiotics by enzymes/proteins expressed on microbial cell surfaces. 相似文献
642.
Nejatizadeh A Kumar R Stobdan T Goyal AK Sikdar S Gupta M Javed S Pasha MA 《Free radical biology & medicine》2008,44(11):1912-1918
Nitric oxide (NO), a potent vasodilator, plays a pivotal role in blood pressure regulation. Endothelial NO synthase gene (NOS3) polymorphisms influence NO levels. Here, we investigated the role of the – 922A/G, – 786T/C, 4b/4a, and 894G/T polymorphisms of the NOS3 and NOx levels in 800 consecutive unrelated subjects comprising 455 patients of essential hypertension and 345 controls. The polymorphisms were investigated independently and as haplotypes. Plasma NOx levels (nitrate and nitrite) were estimated by the Griess method. Genotype frequencies for the –786T/C, 4b/4a, and 894G/T polymorphisms differed significantly (P < 0.001) between patients and controls and were associated with an increased risk of hypertension (OR = 2.0, OR = 3.8, OR = 1.6, respectively). The 4-locus haplotypes ATaG (H1), ATaT (H2), and GCaG (H3) were significantly associated with essential hypertension and served as susceptible haplotypes (P ≤ 0.0001). On the other hand, haplotypes ATbG (H4) and GTbG (H5) were negatively associated with hypertension and served as protective haplotypes (P < 0.0001). NOx levels were significantly lower in patients than controls (P < 0.0001). The individual polymorphisms showed marginal association with NOx level; however, the susceptible haplotype H2 associated significantly with lower NOx levels in patients (P < 0.001) and conversely the haplotype H4 with higher NOx levels in controls (P < 0.001). In conclusion, the 4b/4a and likely – 786T/C polymorphisms were identified as the determinants modifying the risk of hypertension. This study identifies the NOS3 variants and haplotypes as genetic risk factors and as useful markers of increased susceptibility to the risk of essential hypertension. 相似文献
643.
Cleverley RM Saleem M Kean J Ford RC Derrick JP Prince SM 《Molecular membrane biology》2008,25(8):625-630
A method to rapidly assess the oligomeric composition of multimeric proteins is notably absent from reported schemes for high throughput production and crystallization of membrane proteins. In this report we have investigated the suitability of PFO-PAGE electrophoresis for this purpose and present examples where it proves highly informative in selecting conditions favouring the functional oligomeric state of the target protein. Features such as the ability to analyze several samples in parallel, including crude membrane extracts, suggest it will be highly adaptable to high throughput analysis of membrane proteins. 相似文献
644.
A large number of the human microRNAs target lentiviruses, retroviruses, and endogenous retroviruses
Hakim ST Alsayari M McLean DC Saleem S Addanki KC Aggarwal M Mahalingam K Bagasra O 《Biochemical and biophysical research communications》2008,369(2):357-362
Retroelements (including transposons, retrotransposons, retroviruses, and lentiviruses) make up a significant portion of eukaryotic genomes. Given their ability to mutate genes these mobile elements always present a threat to the integrity of the host genomes. Recent studies have revealed complex molecular mechanisms that silence the mutagenic ability of these RE as well strategically express the pieces of the incorporated RE that are utilized to silence human endogenous retroviruses (HERVs) or invading exogenous retroviruses (IERV). We have hypothesized that small endogenous RNA originally evolved to quell “foreign” IERV-genes and subsequently emerged into elaborate silencing systems that include RNA interference, miRNA-based gene regulation and other gene silencing mechanisms. Here, we present evidence that the replication of complex RE are most likely silenced or regulated by homologous miRNA that are found as a part of the cellular repertoire. We analyzed Homo sapiens miRNAs for possible target genetic sequences in selected HERVs and IERV found in humans and other large primates. We identified several miRNAs that have >80% sequence homology with human HERVs; -L, -W, and -K, and IERV like SIVcpz, HTLV-1, and HTLV-2. We found an inverse correlation between the numbers and relative degree of homology of miRNAs to the relative replication capacity of a specific RE. Therefore, larger numbers of miRNAs with greater degree of homology are found against the least active RE and the least numbers of miRNAs with smaller degree of homology are found against the most active RE (i.e. HERV-K). Implications of these observations in RE disease and therapy are discussed. 相似文献
645.
Saleem RA Knoblach B Mast FD Smith JJ Boyle J Dobson CM Long-O'Donnell R Rachubinski RA Aitchison JD 《The Journal of cell biology》2008,181(2):281-292
Reversible phosphorylation is the most common posttranslational modification used in the regulation of cellular processes. This study of phosphatases and kinases required for peroxisome biogenesis is the first genome-wide analysis of phosphorylation events controlling organelle biogenesis. We evaluate signaling molecule deletion strains of the yeast Saccharomyces cerevisiae for presence of a green fluorescent protein chimera of peroxisomal thiolase, formation of peroxisomes, and peroxisome functionality. We find that distinct signaling networks involving glucose-mediated gene repression, derepression, oleate-mediated induction, and peroxisome formation promote stages of the biogenesis pathway. Additionally, separate classes of signaling proteins are responsible for the regulation of peroxisome number and size. These signaling networks specify the requirements of early and late events of peroxisome biogenesis. Among the numerous signaling proteins involved, Pho85p is exceptional, with functional involvements in both gene expression and peroxisome formation. Our study represents the first global study of signaling networks regulating the biogenesis of an organelle. 相似文献
646.
Nisha Jain Kamal Dhawan Sarla P Malhotra Saleem Siddiqui Randhir Singh 《Acta Physiologiae Plantarum》2001,23(3):357-362
Changes in chemical composition and hydrolytic enzyme activities in guava fruits cv. Lucknow-49 have been reported at four
different stages of maturity, viz., mature green (MG), color turning (CT), ripe (R) and over ripe (OR). Chlorophyll content decreased, while carotenoid content
increased with advancement of ripening. Starch content decreased with concomitant increase in alcohol soluble sugars. The
cell wall constituents viz., cellulose, hemicellulose, and lignin decreased up to R stage, while the pectin content decreased throughout up to OR stage.
Among the cell wall hydrolyzing enzymes, polygalacturonase (PG) and cellulase exhibited progressive increase in activity throughout
ripening, while pectin methyl esterase (PME) activity increased up to CT stage and then decreased up to OR stage. The maximum
increase in the activities of cell wall hydrolysing enzymes was observed between MG and CT stages. The activities of starch
hydrolyzing enzymes, α-amylase and β-amylase decreased significantly with advancement of ripening. These changes in the activities
of hydrolyzing enzymes could be considered good indicators of ripening in guava. 相似文献
647.
pRRI2 is a small cryptic plasmid from the rumen bacterium Prevotella ruminicola 223/M2/7 which has been used for the construction of shuttle vectors (pRH3 and pRRI207) that replicate in many Bacteroides/Prevotella strains as well as in Escherichia coli. Sequence analysis of pRRI2 reveals that it is a 3240-bp plasmid carrying two clear open reading frames. Rep, encoded by ORF1, shows 48 and 47% amino acid sequence identity with RepA proteins from Bacteroides vulgatus and Bacteroides fragilis, respectively. ORF2, named Pre, shares 34% amino acid sequence identity with a putative plasmid recombination protein from the Flavobacterium spp. plasmid pFL1 and 30% amino acid sequence identity with BmpH from B. fragilis Tn5520. Disruption of ORF1 with HindIII prevents replication and maintenance in Bacteroides spp. hosts, but shuttle vectors carrying pRRI2 interrupted within ORF2, by EcoRI*, are able to replicate. pRRI2 shows no significant similarity with the only other P. ruminicola plasmid to have been studied previously, pRAM4. 相似文献
648.
Abdel-Rahman Saleem 《Archives Of Phytopathology And Plant Protection》2017,50(19-20):982-996
Strawberry fungi were isolated from fresh fruits and juice on the two types of media (Sabouraud dextrose agar, SDA and potato-dextrose agar, PDA) at 28 °C. Nineteen fungal species belong to 12 genera were isolated from fruits and juice on both isolation media. The most common fungal genera and species were Aspergillus flavus, A. niger, Mucor racemosus, Neurospora crassa, Penicillium chrysogenum, Rhizopus stolonifer and Trichoderma harzianum. Twenty A. flavus and A. parasitics isolates were assayed for their abilities to produce aflatoxins. The concentration of aflatoxins ranged between 25.8–75.2 and 23.6–71.1 ng/ml at 350 and 365 nm, respectively. Among A. flavus and A. parasiticus strains tested, aflatoxin B contributed 30–60% of total isolates. However, G type contributed 85–90%. The Rf values of B1, B2, G1 and G2 were 0.79, 0.61, 0.44 and 0.32, respectively. High-performance liquid chromatography analysis of extracts revealed the presence of aflatoxins with variable levels. 相似文献
649.
650.
Buddhi Prakash Jain Shweta Pandey Nikhat Saleem Goutam K Tanti Shalini Mishra Shyamal K. Goswami 《Cell stress & chaperones》2017,22(6):853-866
SG2NA belongs to a three-member striatin subfamily of WD40 repeat superfamily of proteins. It has multiple protein-protein interaction domains involved in assembling supramolecular signaling complexes. Earlier, we had demonstrated that there are at least five variants of SG2NA generated by alternative splicing, intron retention, and RNA editing. Such versatile and dynamic mode of regulation implicates it in tissue development. In order to shed light on its role in cell physiology, total proteome analysis was performed in NIH3T3 cells depleted of 78 kDa SG2NA, the only isoform expressing therein. A number of ER stress markers were among those modulated after knockdown of SG2NA. In cells treated with the ER stressors thapsigargin and tunicamycin, expression of SG2NA was increased at both mRNA and protein levels. The increased level of SG2NA was primarily in the mitochondria and the microsomes. A mouse injected with thapsigargin also had an increase in SG2NA in the liver but not in the brain. Cell cycle analysis suggested that while loss of SG2NA reduces the level of cyclin D1 and retains a population of cells in the G1 phase, concurrent ER stress facilitates their exit from G1 and traverse through subsequent phases with concomitant cell death. Thus, SG2NA is a component of intrinsic regulatory pathways that maintains ER homeostasis. 相似文献