Evidence that fructose 1,6-bisphosphate specifically protects the α-subunit of pyrophosphate-dependent 6-phosphofructo-1-phosphotransferase against proteolytic degradation

AbstractPyrophosphate-dependent 6-phosphofructo-1-phosphotransferase (PFP) consists of α (regulatory) and β (catalytic) subunits. The α-subunit was previously reported to be much more susceptible to tryptic digestion than the β-subunit. In this study, ligand-induced protection of PFP subunits against proteolysis by subtilisin was investigated in vitro and the data obtained demonstrated that fructose 1,6-bisphosphate (Fru-1,6-P2), while exerting negligible effect on the β-subunit, remarkably protected the α-subunit against proteolytic degradation. Western blot analysis revealed a good correlation between the Fru-1,6-P2 concentration and the degree of corresponding protection on the α-subunit against proteolysis. In contrast, none of other examined ligands including fructose 2,6-bisphosphate, fructose 6-phosphate and pyrophosphate had such protection on the α-subunit. This finding (1) indicates that the stability of the α-subunit can be selectively increased by Fru-1,6-P2, and (2) suggests that Fru-1,6-P2 is likely a special effector of the α-subunit

YAO is a nucleolar WD40-repeat protein critical for embryogenesis and gametogenesis in Arabidopsis

<p>Abstract</p> <p>Background</p> <p>In flowering plants, gametogenesis generates multicellular male and female gametophytes. In the model system Arabidopsis, the male gametophyte or pollen grain contains two sperm cells and a vegetative cell. The female gametophyte or embryo sac contains seven cells, namely one egg, two synergids, one central cell and three antipodal cells. Double fertilization of the central cell and egg produces respectively a triploid endosperm and a diploid zygote that develops further into an embryo. The genetic control of the early embryo patterning, especially the initiation of the first zygotic division and the positioning of the cell plate, is largely unknown.</p> <p>Results</p> <p>Here we report the characterization of a mutation, <it>yaozhe (yao)</it>, that causes zygote arrest and misplacement of cell plate of the zygote, leading to early embryo lethality. In addition, gametophyte development is partially impaired. A small portion of the mutant embryo sacs are arrested at four-nucleate stage with aberrant nuclear positioning. Furthermore, the competence of male gametophytes is also compromised. <it>YAO </it>encodes a nucleolar protein with seven WD-repeats. Its homologues in human and yeast have been shown to be components of the U3 snoRNP complex and function in 18S rRNA processing. <it>YAO </it>is expressed ubiquitously, with high level of expression in tissues under active cell divisions, including embryo sacs, pollen, embryos, endosperms and root tips.</p> <p>Conclusions</p> <p>Phenotypic analysis indicated that <it>YAO </it>is required for the correct positioning of the first zygotic division plane and plays a critical role in gametogenesis in Arabidopsis. Since YAO is a nucleolar protein and its counterparts in yeast and human are components of the U3 snoRNP complex, we therefore postulate that YAO is most likely involved in rRNA processing in plants as well.</p

Efficient CRISPR-Cas9 mediated gene disruption in primary erythroid progenitor cells

The study of isolated primary progenitor cells offers great insight into developmental biology and human disease. In particular, ex vivo culture of isolated primary erythroid progenitor cells replicates the differentiation events that occur during in vivo erythropoiesis. Herein we report a high-efficiency method for CRISPR-Cas9 mediated gene disruption in isolated primary erythroid progenitor cells. We use this method to generate the novel result that Lmna is required in terminal erythroid differentiation.Frederick Lovejoy (Research Grant)National Institutes of Health (U.S.) (grant NIH/NHLBI 2 P01 HL032262-25

(-)-Epigallocatechin-3-Gallate Induces Non-Apoptotic Cell Death in Human Cancer Cells via ROS-Mediated Lysosomal Membrane Permeabilization

10.1371/journal.pone.0046749PLoS ONE710

{6,6′-Dimeth­oxy-2,2′-[4-bromo-o-phenyl­enebis(nitrilo­methyl­idyne)]diphenolato}nickel(II) methanol solvate

In the title compound, [Ni(C22H17BrN2O4)]·CH3OH, the NiII ion is in a slightly distorted square-planar geometry involving an N2O2 atom set of the tetra­dentate Schiff base ligand. The asymmetric unit contains one nickel complex and one methanol solvent mol­ecule. The dihedral angle between the aromatic ring planes of the central aromatic ring and other two aromatic rings are 10.8 (3) and 6.0 (2)°. The crystal structure is stabilized by inter­molecular C—H⋯O and C—H⋯Br and by intra­molecular O—H⋯O hydrogen bonds

Vertically-aligned graphene nanowalls grown via plasma-enhanced chemical vapor deposition as a binder-free cathode in Li-O_2 batteries

In the present report, vertically-aligned graphene nanowalls are grown on Ni foam (VA-G/NF) using plasma-enhanced chemical vapor deposition method at room temperature. Optimization of the growth conditions provides graphene sheets with controlled defect sites. The unique architecture of the vertically-aligned graphene sheets allows sufficient space for the ionic movement within the sheets and hence enhancing the catalytic activity. Further modification with ruthenium nanoparticles (Ru NPs) drop-casted on VA-G/NF improves the charge overpotential for lithium–oxygen (Li–O_2) battery cycles. Such reduction we believe is due to the easier passage of ions between the perpendicularly standing graphene sheets thereby providing ionic channels

Unraveling the effect of salt chemistry on long-durability high-phosphorus-concentration anode for potassium ion batteries

Phosphorus-based anode materials are of considerable interest for grid-scale energy storage systems due to their high theoretical capacity. Nevertheless, the low electrical conductivity of P, large volume changes during cycling, and highly-reactive phosphide surface are hindering their potential applications. Herein, outstanding long-term cycling stability with high retained potassium storage capacity (213.7 mA h g−1over 2000 cycles) was achieved via the introduction of an alternative potassium bis(fluorosulfonyl)imide (KFSI) salt and by using a layered compound (GeP5) with a high phosphorus concentration as anode material. Fourier transform infrared spectroscopic mapping results suggest that KFSI salt helps to form an uniform solid electrolyte interphase (SEI) layer and reduces the side reactions at the electrode/electrolyte interface, thus enhancing the cycling performance. In-operando synchrotron X-ray diffraction analysis has revealed the synergistic reaction mechanisms of the K-P and K-Ge reactions. These findings indicate the enormous potential of phosphorus-based anodes for high-performance potassium ion batteries and can attract broad interest for regulating the SEI layer formation through manipulating the salt chemistry

Vertically-aligned graphene nanowalls grown via plasma-enhanced chemical vapor deposition as a binder-free cathode in Li-O_2 batteries

In the present report, vertically-aligned graphene nanowalls are grown on Ni foam (VA-G/NF) using plasma-enhanced chemical vapor deposition method at room temperature. Optimization of the growth conditions provides graphene sheets with controlled defect sites. The unique architecture of the vertically-aligned graphene sheets allows sufficient space for the ionic movement within the sheets and hence enhancing the catalytic activity. Further modification with ruthenium nanoparticles (Ru NPs) drop-casted on VA-G/NF improves the charge overpotential for lithium–oxygen (Li–O_2) battery cycles. Such reduction we believe is due to the easier passage of ions between the perpendicularly standing graphene sheets thereby providing ionic channels

High-Resolution Imaging of Dendrimers Used in Drug Delivery via Scanning Probe Microscopy

Dendrimers and telodendrimer micelles represent two new classes of vehicles for drug delivery that have attracted much attention recently. Their structural characterization at the molecular and submolecular level remains a challenge due to the difficulties in reaching high resolution when imaging small particles in their native media. This investigation offers a new approach towards this challenge, using scanning tunneling microscopy (STM) and atomic force microscopy (AFM). By using new sample preparation protocols, this work demonstrates that (a) intramolecular features such as drug molecules and dendrimer termini can be resolved; and (b) telodendrimer micelles can be immobilized on the surface without compromising structural integrity, and as such, high resolution AFM imaging may be performed to attain 3D information. This high-resolution structural information should enhance our knowledge of the nanocarrier structure and nanocarrier-drug interaction and, therefore, facilitate design and optimization of the efficiency in drug delivery

Growth performance of brown-golden marine microalga, Isochrysis sp., cultivated in alternative algal culture media

The present study aimed to evaluate the suitability of introduced algal culture media as an alternative to the general enriched seawater media in the laboratory cultivation of Isochrysis sp., a marine microalga commonly cultivated for aquaculture purposes. Isochrysis sp. was established into culture in three replications using three experimental algal culture media (Walne’s medium as a control, China-contributed culture medium (CCM) and CCM supplemented with vitamins (CCM + Vit)). The experiment was performed with a continuous illumination for a period of seven days at 25±1°C. The effect of introduced algal culture media (CCM and CCM + Vit) on the growth performance of Isochrysis sp. was highlighted. CCM demonstrated promising results for the cultivation of Isochrysis sp. A maximum cell density of 9.16×106 ± 5.40×105 cells mL-1, which corresponded to an instantaneous growth rate (r) of 0.21 cell day-1 and a doubling time (T2) of 3.29 days, was observed in Isochrysis sp. cultivated in CCM. In view of its potential and reduced preparation labour, CCM may be recommended as an alternative to the general enriched seawater media in the cultivation of Isochrysis sp. in laboratories with basic facility as well as small- and medium-scale aquaculture hatcheries