A bifunctional fusion between beta-glucuronidase and neomycin phosphotransferase: a broad-spectrum marker enzyme for plants.

We have used an in vivo selection approach to isolate a gene encoding a bifunctional fusion peptide between Escherichia coli beta-glucuronidase (GUS) and neomycin phosphotransferase II (NPT-II) from transposon Tn5 in the NH2-GUS::NPT-II-COOH configuration. The fused gene is predicted to encode a fusion peptide 885 amino acids long, and was shown in E. coli to synthesize a 97-kDa GUS+ NPT-II+ gene product. Gel-filtration chromatography suggested that, while the native GUS may be active as a dimer and NPT-II as a monomer, the elution profile of the fusion protein is consistent with that of a trimer. The fusion marker has been produced and defined in transgenic Nicotiana tabacum plants, where both the chimeric gene and the gene product were stable. The bifunctional gene enabled direct KmR selection at the callus stage and enzymatic or histochemical assessment of the steady-state production of GUS activity in regenerated plants. In addition to allowing structure-function determination for the GUS and NPT-II domains of the fusion peptide, the gus::npt-II gene simplifies vector constructs where both marker domains are desired.     

Biogenic Synthesis of Selenium Nanoparticles and Their Effect on As(III)-Induced Toxicity on Human Lymphocytes

A bioreductive capacity of a plant, Terminalia arjuna leaf extract, was utilized for preparation of selenium nanoparticles. The leaf extract worked as good capping as well as stabilizing agent and facilitated the formation of stable colloidal nanoparticles. Resulting nanoparticles were characterized using UV–Vis spectrophotometer, transmission electron microscopy (TEM), energy dispersive X-ray analysis (EDAX), Fourier transform infrared spectroscopy (FT-IR), and X-ray diffraction analysis (XRD), respectively. The colloidal solution showed the absorption maximum at 390 nm while TEM and selected area electron diffraction (SAED) indicated the formation of polydispersed, crystalline selenium nanoparticles of size raging from 10 to 80 nm. FT-IR analysis suggested the involvement of O–H, N–H, C=O, and C–O functional group of the leaf extract in particle formation while EDAX analysis indicated the presence of selenium in synthesized nanoparticles. The effect of nanoparticles on human lymphocytes treated with arsenite, As(III), has been studied. Studies on cell viability using MTT assay and DNA damage using comet assay revealed that synthesized selenium nanoparticles showed protective effect against As(III)-induced cell death and DNA damage. Chronic ingestion of arsenic infested groundwater, and prevalence of arsenicosis is a serious public health issue. The synthesized benign nanoselenium can be a promising agent to check the chronic toxicity caused due to arsenic exposure.     

Mitochondrial DNA variations in ova and blastocyst: Implications in assisted reproduction

Mitochondrial DNA (mtDNA) of oocyte is critical for its function, embryo quality and development. Analysis of complete mtDNA of 49 oocytes and 18 blastocysts from 67 females opting for IVF revealed 437 nucleotide variations. 40.29% samples had either disease associated or non-synonymous novel or pathogenic mutation in evolutionarily conserved regions. Samples with disease associated mtDNA mutations had low fertilization rate and poor embryo quality, however no difference in implantation or clinical pregnancy rate was observed. Screening mtDNA from oocyte/blastocyst is a simple, clinically reliable method for diagnostic evaluation of female infertility and may reduce risk of mtDNA disease transmission.     

Overexpression of a Novel Biotrophy-Specific Colletotrichum truncatum Effector,CtNUDIX, in Hemibiotrophic Fungal Phytopathogens Causes Incompatibility with Their Host Plants

The hemibiotrophic fungus Colletotrichum truncatum causes anthracnose disease on lentils and a few other grain legumes. It shows initial symptomless intracellular growth, where colonized host cells remain viable (biotrophy), and then switches to necrotrophic growth, killing the colonized host plant tissues. Here, we report a novel effector gene, CtNUDIX, from C. truncatum that is exclusively expressed during the late biotrophic phase (before the switch to necrotrophy) and elicits a hypersensitive response (HR)-like cell death in tobacco leaves transiently expressing the effector. CtNUDIX homologs, which contain a signal peptide and a Nudix hydrolase domain, may be unique to hemibiotrophic fungal and fungus-like plant pathogens. CtNUDIX lacking a signal peptide or a Nudix motif failed to induce cell death in tobacco. Expression of CtNUDIX:eGFP in tobacco suggested that the fusion protein might act on the host cell plasma membrane. Overexpression of CtNUDIX in C. truncatum and the rice blast pathogen, Magnaporthe oryzae, resulted in incompatibility with the hosts lentil and barley, respectively, by causing an HR-like response in infected host cells associated with the biotrophic invasive hyphae. These results suggest that C. truncatum and possibly M. oryzae elicit cell death to signal the transition from biotrophy to necrotrophy.     

Phytochemical evaluation and anticancer activity of rambutan (Nephelium lappaceum) fruit endocarp extracts against human hepatocellular carcinoma (HepG-2) cells

The current investigation was taken to screen the phytoconstituents present in fruit endocarp various extracts of Nephelium lappaceum commonly called as Rambutan fruit and its anticancer property against human hepatocellular carcinoma (HepG-2) cells. Different analytical techniques including qualitative phytochemical analysis, cell viability assay (MTT), apoptotic nuclear staining (DAPI), DNA fragmentation assay, Attenuated total reflection (ATR) and Gas chromatography–mass spectrometry (GC–MS) spectral analysis were carried out. ATR and GC–MS study revealed the presence of functional groups and 9 compounds, respectively in methanol endocarp extract. The results obtained depicts that methanol endocarp extract profoundly controlled cell proliferation and caused shrinkage of HepG-2 cells from polygonal to spherical shape. DAPI staining revealed that methanol endocarp extract caused increased fragmentation of nucleus and DNA fragmentation, which can be taken as a sign of apoptosis. The anticancer potential of methanol fruit endocarp extract of Nephelium lappaceum than other extracts and could be used successfully in future drug delivery systems and other biomedical concerns.     

Molecular docking analysis of the BRCA1 protein with compounds from Justica adhatoda L

BRCA1 is a human tumour suppression gene. Therefore, it is of interest to document the Molecular docking analysis data of the BRCA1 protein with compounds from Justica adhatoda L (adhatoda). We report that Amrinone, Hexadecanoic acid, Pyrazinamide & Vasicinone have acceptable binding features with the BRCA1 protein for further consideration.     

Genetic engineering modification and fermentation optimization for extracellular production of recombinant proteins using Escherichia coli

Applied Microbiology and Biotechnology - As a common expression host, Escherichia coli has received more and more attention due to the recently developed secretory expression system, which offers...     

The porin AaxA protein model from Chlamydia pneumonia

Chlamydophila pneumoniae is an intracellular pathogen accountable for various acute respiratory infections. C. pneumoniae has a gene cluster which encodes a putative outer membrane porin (aaxA), arginine decarboxylase (CPn1032 or aaxB) and a putative cytoplasmic membrane transporter (CPn1031 or aaxC). Therefore, it is of interest to document a molecular protein model of porin AaxA from Chlamydia pneumonia to gain structure to functional insight on the protein.