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91.
Identification and characterization of a UDP-D-glucuronate 4-epimerase in Arabidopsis 总被引:1,自引:0,他引:1
Usadel B Schlüter U Mølhøj M Gipmans M Verma R Kossmann J Reiter WD Pauly M 《FEBS letters》2004,569(1-3):327-331
One of the major sugars present in the plant cell wall is d-galacturonate, the dominant monosaccharide in pectic polysaccharides. Previous work indicated that one of the activated precursors necessary for the synthesis of pectins is UDP-d-galacturonate, which is synthesized from UDP-d-glucuronate by a UDP-d-glucuronate 4-epimerase (GAE). Here, we report the identification, cloning and characterization of a GAE6 from Arabidopsis thaliana. Functional analysis revealed that this enzyme converts UDP-d-glucuronate to UDP-d-galacturonate in vitro. An expression analysis of this epimerase and its five homologs in the Arabidopsis genome by quantitative RT-PCR and promoter::GUS fusions indicated differential expression of the family members in plant tissues and expression of all isoforms in the developing pollen of A. thaliana. 相似文献
92.
An organophosphorus pesticide malathion biodegradation was investigated by using the bacteria Ochrobactrum sp. M1D isolated from a soil sample of peach orchards in Palampur, District Kangra, Himachal Pradesh (India). The bacterium was able to utilize malathion as the sole source of carbon and energy. The isolated bacterium was found psychrotolerant and could degrade 100% of 100 mg l−1 malathion in minimal salt medium at 20°C, pH 7·0 within 12 days with no major significant metabolites left at the end of the study. Through GCMS analysis, methyl phosphate, diethyl maleate, and diethyl 2-mercaptosuccinate were detected and identified as the major pathway metabolites. Based on the GCMS profile, three probable degradation pathways were interpreted. The present study is the first report of malathion biodegradation at both the psychrophilic and mesophilic conditions by any psychrotolerant strain and also through multiple degradation pathways. In the future, the strain can be explored to bio-remediate the malathion contaminated soil in the cold climatic region and to utilize the enzymatic systems for advanced biotechnology applications. 相似文献
93.
The present study has been designed to investigate the effect of benfotiamine, a thiamine derivative, in sodium arsenite-induced
vascular endothelial dysfunction (VED) in rats. Sodium arsenite (1.5 mg−1 kg−1 day−1 i.p., 2 weeks) was administered in rats to produce VED. The development of VED was assessed by employing isolated aortic
ring preparation and estimating the serum and aortic concentrations of nitrite/nitrate. Further, the integrity of vascular
endothelium in thoracic aorta was assessed by scanning electron microscopy. Moreover, the oxidative stress was assessed by
estimating serum thiobarbituric acid reactive substances (TBARS) and aortic superoxide anion generation. The administration
of sodium arsenite markedly produced VED by attenuating acetylcholine-induced endothelium-dependent relaxation, decreasing
serum and aortic concentrations of nitrite/nitrate, and impairing the integrity of vascular endothelium. Further, sodium arsenite
produced oxidative stress by increasing serum TBARS and aortic superoxide generation. The treatment with benfotiamine (25,
50, and 100 mg−1 kg−1 day−1 p.o.) or atorvastatin (30 mg−1 kg−1 day−1 p.o., a standard agent) prevented sodium arsenite-induced VED and oxidative stress. However, the beneficial effects of benfotiamine
in preventing the sodium arsenite-induced VED were attenuated by co-administration with N-omega-nitro-l-arginine methyl ester (L-NAME) (25 mg−1 kg−1 day−1, i.p.), an inhibitor of NOS. Thus, it may be concluded that benfotiamine reduces oxidative stress and activates endothelial
nitric oxide synthase to enhance the generation and bioavailability of NO and subsequently improves the integrity of vascular
endothelium to prevent sodium arsenite-induced experimental VED. 相似文献
94.
Nora Wallot-Hieke Neha Verma David Schlütermann Niklas Berleth Jana Deitersen Philip Böhler 《Autophagy》2018,14(5):743-763
Macroautophagy/autophagy is an evolutionarily conserved cellular process whose induction is regulated by the ULK1 protein kinase complex. The subunit ATG13 functions as an adaptor protein by recruiting ULK1, RB1CC1 and ATG101 to a core ULK1 complex. Furthermore, ATG13 directly binds both phospholipids and members of the Atg8 family. The central involvement of ATG13 in complex formation makes it an attractive target for autophagy regulation. Here, we analyzed known interactions of ATG13 with proteins and lipids for their potential modulation of ULK1 complex formation and autophagy induction. Targeting the ATG101-ATG13 interaction showed the strongest autophagy-inhibitory effect, whereas the inhibition of binding to ULK1 or RB1CC1 had only minor effects, emphasizing that mutations interfering with ULK1 complex assembly do not necessarily result in a blockade of autophagy. Furthermore, inhibition of ATG13 binding to phospholipids or Atg8 proteins had only mild effects on autophagy. Generally, the observed phenotypes were more severe when autophagy was induced by MTORC1/2 inhibition compared to amino acid starvation. Collectively, these data establish the interaction between ATG13 and ATG101 as a promising target in disease-settings where the inhibition of autophagy is desired. 相似文献
95.
Surendra K. Gond Ashish Mishra Vijay K. Sharma Satish K. Verma Jitendra Kumar Ravindra N. Kharwar Anuj Kumar 《Mycoscience》2012,53(2):113-121
Endophytic fungi from Nyctanthes arbor-tristis were isolated and evaluated for their antimicrobial activity. A total of 19 endophytic fungi were isolated from 400 segments
of healthy leaf and stem tissues of N. arbor-tristis. Eighteen endophytic fungi were obtained from leaf, while only ten from stem. Alternaria alternata had the highest colonization frequency (15.0%) in leaf, whereas Cladosporium cladosporioides ranked first in stem with a colonization frequency of 12%. The diversity and species richness were found higher in leaf tissues
than in stem. The similarity indices between leaf and stem were 0.473 for Jaccard’s and 0.642 for the Sorenson index, respectively.
Of 16, 12 (75%) endophytic fungal extracts showed antibacterial activity against either one or more pathogenic bacteria. The
endophytic Nigrospora oryzae showed maximum inhibition against Shigella sp. and Pseudomonas aeruginosa. The leaf endophytes Colletotrichum dematium and Chaetomium globosum exhibited a broad range of anibacterial activity and were active against Shigella flexnii, Shigella boydii, Salmonella enteritidis, Salmonella paratyphi, and P. aeruginosa. Nine out of 16 (56.25%) endophytic fungi exhibited antifungal activity to one or more fungal pathogens. Colletotrichum dematium inhibited 55.87% of the radial growth of the phytopathogen Curvularia lunata. The antimicrobial activity of these endophytic microorganisms could be exploited in the biotechnological, medicinal, and
agricultural industries. 相似文献
96.
Meena Lall Ratna Puri Pushpa Saviour Ishwar Verma 《Indian journal of human genetics》2012,18(2):238-240
Chromosome inversions are intra-chromosomal rearrangements formed when the chromosome breaks occur at two places, and in the process of repair the intervening segments are joined in an inverted or opposite manner. Inversions themselves do not appear to cause clinical anomalies, if balanced. Abnormal phenotypes can occur due to gene disruption at the point of breakage and reunion or due to duplication/deficiency recombinants formed during crossover at meiosis. We report a case with familial deletion 4q syndrome in a 1-year-old female child with dysmorphism and congenital abnormalities. The deletion was an outcome of a paracentric inversion 4q31.2q35.2. The deletion was confirmed by fluorescence in situ hybridization using telomeric DNA probes for chromosome No. 4. An attempt was made to correlate the genotype with the phenotype. The father had the same rearrangement with a milder phenotype. The recurrence risk in such cases is high. 相似文献
97.
Rinky Rajput Ved Vrat Verma Vishal Chaudhary Rani Gupta 《Extremophiles : life under extreme conditions》2013,17(1):29-41
??-Glutamyl transpeptidase of a thermo-acidophilic archaeon Picrophilus torridus was cloned and expressed using E. coli Rosetta-pET 51b(+) expression system. The enzyme was expressed at 37 °C/200 rpm with ??-GT production of 1.99 U/mg protein after 3 h of IPTG induction. It was improved nearby 10-fold corresponding to 18.92 U/mg protein in the presence of 2 % hexadecane. The enzyme was purified by Ni2+-NTA with a purification fold of 3.6 and recovery of 61 %. It was synthesized as a precursor heterodimeric protein of 47 kDa with two subunits of 30 kDa and 17 kDa, respectively, as revealed by SDS-PAGE and western blot. The enzyme possesses hydrolase activity with optima at pH 7.0 and 55 °C. It was thermostable with a t 1/2 of 1 h at 50 °C and 30 min at 60 °C, and retained 100 % activity at 45 °C even after 24 h. It was inhibited by azaserine and DON and PMSF. Pt??-GT shared 37 % sequence identity and 53 % homology with an extremophile ??-GT from Thermoplasma acidophilum. Functional residues identified by in silico approaches were further validated by site-directed mutagenesis where Tyr327 mutated by Asn327 introduced significant transpeptidase activity. 相似文献
98.
Callose synthase (CalS5) is required for exine formation during microgametogenesis and for pollen viability in Arabidopsis 总被引:2,自引:0,他引:2
Dong X Hong Z Sivaramakrishnan M Mahfouz M Verma DP 《The Plant journal : for cell and molecular biology》2005,42(3):315-328
Callose (beta-1,3-glucan) is produced at different locations in response to biotic and abiotic cues. Arabidopsis contains 12 genes encoding callose synthase (CalS). We demonstrate that one of these genes, CalS5, encodes a callose synthase which is responsible for the synthesis of callose deposited at the primary cell wall of meiocytes, tetrads and microspores, and the expression of this gene is essential for exine formation in pollen wall. CalS5 encodes a transmembrane protein of 1923 amino acid residues with a molecular mass of 220 kDa. Knockout mutations of the CalS5 gene by T-DNA insertion resulted in a severe reduction in fertility. The reduced fertility in the cals5 mutants is attributed to the degeneration of microspores. However, megagametogenesis is not affected and the female gametes are completely fertile in cals5 mutants. The CalS5 gene is also expressed in other organs with the highest expression in meiocytes, tetrads, microspores and mature pollen. Callose deposition in the cals5 mutant was nearly completely lacking, suggesting that this gene is essential for the synthesis of callose in these tissues. As a result, the pollen exine wall was not formed properly, affecting the baculae and tectum structure and tryphine was deposited randomly as globular structures. These data suggest that callose synthesis has a vital function in building a properly sculpted exine, the integrity of which is essential for pollen viability. 相似文献
99.
P De Togni H Niman V Raymond P Sawchenko I M Verma 《Molecular and cellular biology》1988,8(5):2251-2256
We have generated monoclonal antibodies by using a synthetic peptide corresponding to amino acid positions 4 to 17 of the human fos protein. The antibodies detected both v- and c-fos proteins by immunoprecipitation, immunoblotting, and indirect immunofluorescence. The monoclonal antibodies not only identified the fos protein complex with the cellular 39-kilodalton protein, but also recognized the modified forms of the mouse, rat, and human fos proteins. In day-17 rat embryos, nuclear-staining fos protein could be identified in the cartilage by immunohistochemical staining. 相似文献
100.
Nahla V Bassil Thomas M Davis Hailong Zhang Stephen Ficklin Mike Mittmann Teresa Webster Lise Mahoney David Wood Elisabeth S Alperin Umesh R Rosyara Herma Koehorst-vanc Putten Amparo Monfort Daniel J Sargent Iraida Amaya Beatrice Denoyes Luca Bianco Thijs van Dijk Ali Pirani Amy Iezzoni Dorrie Main Cameron Peace Yilong Yang Vance Whitaker Sujeet Verma Laurent Bellon Fiona Brew Raul Herrera Eric van de Weg 《BMC genomics》2015,16(1)