Anti-microbiological activities of bio-synthesized silver Nano-stars by Saccharopolyspora hirsuta

A novel strain of Saccaropolyspora hirsuta was isolated from an insect Tapinoma simrothi for the first time and was morphologically and physiologically characterized. It was genetically identified using 16S rRNA and sequence similarity percentage in genbank with closely related species as strain ess_amA6 of Saccaropolyspora hirsuta. The accession number of strain ess_amA6 is KF996506. Antagonistic activity of strain ess_amA6 against some pathogenic Gram positive and negative bacteria, and unicellular fungus Candida albicans was studied. In addition, star shaped silver nanoparticles were biosynthesized using strain ess_amA6. The silver Nano stars were characterized by UV-us spectrophotometer. Fourier transform infrared spectroscopy analysis confirmed the conversion of Ag+ ions to Nano silver due to the reduction by capping material of extract. Transmission electron microscopically studies of biosynthesized Nano silver particles showed that they are spherical ranging from 10?nm to 30?nm in size. Silver atoms were checked in Nano sample by Energy Dispersive X-ray spectroscopy. Bioactivity of biosynthesized Nano silver was observed against some pathogenic microorganisms such as Staphylococcus aureus, Streptococcus pyogenes, Salmonella typhi, pseudomonas aeruginosa, Klebsiella pneumonia and Candida albicans. These tested microbes were highly sensitive to Nano silver. This study recommended that strain ess_amA6 can be used to effectively biosynthesize bioactive Nano silver compounds.     

Knockdown of p53 suppresses Nanog expression in embryonic stem cells

Mouse embryonic stem cells (ESCs) express high levels of cytoplasmic p53. Exposure of mouse ESCs to DNA damage leads to activation of p53, inducing Nanog suppression. In contrast to earlier studies, we recently reported that chemical inhibition of p53 suppresses ESC proliferation. Here, we confirm that p53 signaling is involved in the maintenance of mouse ESC self-renewal. RNA interference-mediated knockdown of p53 induced downregulation of p21 and defects in ESC proliferation. Furthermore, p53 knockdown resulted in a significant downregulation in Nanog expression at 24 and 48 h post-transfection. p53 knockdown also caused a reduction in Oct4 expression at 48 h post-transfection. Conversely, exposure of ESCs to DNA damage caused a higher reduction of Nanog expression in control siRNA-treated cells than in p53 siRNA-treated cells. These data show that in the absence of DNA damage, p53 is required for the maintenance of mouse ESC self-renewal by regulating Nanog expression.     

Sequencing and Utilization of the Gossypium Genomes

Revealing the genetic underpinnings of cotton productivity will require understanding both the prehistoric evolution of spinnable fibers, and the results of independent domestication processes in both the Old and New Worlds. Progress toward a reference sequence for the smallest Gossypium genome is a logical stepping-stone toward revealing diversity in the remaining seven genomes (A, B, C, E, F, G, K) that permitted Gossypium species to adapt to a wide range of ecosystems in warmer arid regions of the world, and toward identifying the emergent properties that account for the superior productivity and quality of tetraploid cottons. The greatest challenge facing the cotton community is not genome sequencing per se but the conversion of sequence to knowledge.     

Revised model for Enterococcus faecalis fsr quorum-sensing system: the small open reading frame fsrD encodes the gelatinase biosynthesis-activating pheromone propeptide corresponding to staphylococcal agrd

Gelatinase biosynthesis-activating pheromone (GBAP) is an autoinducing peptide involved in Enterococcus faecalis fsr quorum sensing, and its 11-amino-acid sequence has been identified in the C-terminal region of the 242-residue deduced fsrB product (J. Nakayama et al., Mol. Microbiol. 41:145-154, 2001). In this study, however, we demonstrated the existence of fsrD, encoding the GBAP propeptide, which is in frame with fsrB but is translated independently of fsrB. It was also demonstrated that FsrB', an FsrD segment-truncated FsrB, functions as a cysteine protease-like processing enzyme to generate GBAP from FsrD. This revised model is consistent with the staphylococcal agr system.     

Contrasting Effects of α-Synuclein and γ-Synuclein on the Phenotype of Cysteine String Protein α (CSPα) Null Mutant Mice Suggest Distinct Function of these Proteins in Neuronal Synapses

In neuronal synapses, neurotransmitter-loaded vesicles fuse with presynaptic plasma membrane in a complex sequence of tightly regulated events. The assembly of specialized SNARE complexes plays a pivotal role in this process. The function of the chaperone cysteine string protein α (CSPα) is important for synaptic SNARE complex formation, and mice lacking this protein develop severe synaptic dysfunction and neurodegeneration that lead to their death within 3 months after birth. Another presynaptic protein, α-synuclein, also potentiates SNARE complex formation, and its overexpression rescues the phenotype of CSPα null mutant mice, although these two proteins use different mechanisms to achieve this effect. α-Synuclein is a member of a family of three related proteins whose structural similarity suggests functional redundancy. Here, we assessed whether γ-synuclein shares the ability of α-synuclein to bind synaptic vesicles and ameliorate neurodegeneration caused by CSPα deficiency in vivo. Although the N-terminal lipid-binding domains of the two synucleins showed similar affinity for purified synaptic vesicles, the C-terminal domain of γ-synuclein was not able to interact with synaptobrevin-2/VAMP2. Consequently, overexpression of γ-synuclein did not have any noticeable effect on the phenotype of CSPα null mutant mice. Our data suggest that the functions of α- and γ-synucleins in presynaptic terminals are not fully redundant.     

Mutations disrupting selenocysteine formation cause progressive cerebello-cerebral atrophy

The essential micronutrient selenium is found in proteins as selenocysteine (Sec), the only genetically encoded amino acid whose biosynthesis occurs on its cognate tRNA in humans. In the final step of selenocysteine formation, the essential enzyme SepSecS catalyzes the conversion of Sep-tRNA to Sec-tRNA. We demonstrate that SepSecS mutations cause autosomal-recessive progressive cerebellocerebral atrophy (PCCA) in Jews of Iraqi and Moroccan ancestry. Both founder mutations, common in these two populations, disrupt the sole route to the biosynthesis of the 21st amino acid, Sec, and thus to the generation of selenoproteins in humans.     

Blocking mitochondrial pyruvate import in brown adipocytes induces energy wasting via lipid cycling

Combined fatty acid esterification and lipolysis, termed lipid cycling, is an ATP‐consuming process that contributes to energy expenditure. Therefore, interventions that stimulate energy expenditure through lipid cycling are of great interest. Here we find that pharmacological and genetic inhibition of the mitochondrial pyruvate carrier (MPC) in brown adipocytes activates lipid cycling and energy expenditure, even in the absence of adrenergic stimulation. We show that the resulting increase in ATP demand elevates mitochondrial respiration coupled to ATP synthesis and fueled by lipid oxidation. We identify that glutamine consumption and the Malate‐Aspartate Shuttle are required for the increase in Energy Expenditure induced by MPC inhibition in Brown Adipocytes (MAShEEBA). We thus demonstrate that energy expenditure through enhanced lipid cycling can be activated in brown adipocytes by decreasing mitochondrial pyruvate availability. We present a new mechanism to increase energy expenditure and fat oxidation in brown adipocytes, which does not require adrenergic stimulation of mitochondrial uncoupling.     

Antibody profile in symptomatic/asymptomatic severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infected Saudi persons

The severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2)-infected persons could be symptomatic or asymptomatic. Asymptomatic and symptomatic patients can transmit SARS-CoV-2. This study aimed to study the humoral immune response in Saudis who are Covid-19 symptomatic and asymptomatic patients. We created three types of enzyme-linked immunosorbant assays (ELISAs) to reveal IgG and IgM antibodies (Abs) against SARS-CoV-2. The developed ELISAs were designed to detect Abs against SARS-CoV-2 N, S and N + S proteins. A number of Covid-19 symptomatic (1 5 3) and asymptomatic (84) RT–PCR-confirmed patient sera were used to evaluate the ELISAs and to determine the IgG and IgM antibody profile in those patients. The sensitivity and specificity of these ELISAs were evaluated using pre-Covid-19 pandemic serum samples. The results revealed the existence of anti-SARS-CoV-2 IgG and IgM Abs in Covid-19 symptomatic and asymptomatic Saudi persons. The use of SARS-CoV-2 N and S proteins in the same ELISA greatly increased the detectability of infection. In conclusion, the Covid-19 symptomatic and asymptomatic Saudi persons demonstrated both IgG and IgM antibody profile with higher titer in symptomatic patients. The use of N + S proteins as antibody capture antigens greatly increased the ELISA sensitivity.     

Halotropism Is a Response of Plant Roots to Avoid a Saline Environment

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