Mode of interaction of the Gαo subunit of heterotrimeric G proteins with the GoLoco1 motif of Drosophila Pins is determined by guanine nucleotides.

Drosophila GoLoco motif-containing protein Pins is unusual in its highly efficient interaction with both GDP- and the GTP-loaded forms of the α-subunit of the heterotrimeric Go protein. We analysed the interactions of Gαo in its two nucleotide forms with GoLoco1-the first of the three GoLoco domains of Pins-and the possible structures of the resulting complexes, through combination of conventional fluorescence and FRET measurements as well as through molecular modelling. Our data suggest that the orientation of the GoLoco1 motif on Gαo significantly differs between the two nucleotide states of the latter. In other words, a rotation of the GoLoco1 peptide in respect with Gαo must accompany the nucleotide exchange in Gαo. The sterical hindrance requiring such a rotation probably contributes to the guanine nucleotide exchange inhibitor activity of GoLoco1 and Pins as a whole. Our data have important implications for the mechanisms of Pins regulation in the process of asymmetric cell divisions

Physicochemical characteristics of modification of chaperon groel apical domain designed to enhance expression and stability of target proteins [Физико-химическая характеристика варианта апикального домена шаперона GroEL для повышения уровня биосинтеза и увеличения стабильности целевых белков]

Описаны свойства нового белка, являющегося вариантом апикального домена шаперона GroEL, предназначенного служить лидером при создании слитых белков. Данный полипептидный лидер демонстрирует высокий уровень биосинтеза в бактериальной системе, растворим и сохраняет растворимость после стандартных биохимических манипуляций. Исследована его вторичная структура и ее термостабильность, а также растворимость белка в широком диапазоне температур. Для упрощения процедуры последующей очистки целевого белка предусмотрена возможность его химического отщепления по остатку метионина под действием бромциана.The expression of heterologous proteins in bacterial system is often impeded or even impossible due, for instance, to their lability, hydrophobicity or toxicity. In many cases, the problem can be partially or completely solved by creating fusion proteins with a leader able to enhance the solubility or stability of a target protein. In this work, the properties of a new protein, a modification of GroEL apical domain, designed to be a leader in fusion systems have been described. This polypeptide leader demonstrates a high level of expression in the bacterial system; it is soluble and retains its solubility after standard biochemical manipulations. The secondary structure of the protein and its thermal stability, and also the protein solubility were studied in the wide temperature range. To simplify the following purification of the target protein, a possibility of its chemical cleavage from the fused protein at the methionine residues using cyan bromide is provided. © 2009-2017 State Research Institute for Genetics and Selection of Industrial

PRESENT STATUS OF THE MICHIGAN-MIT ULTRA-COLD POLARIZED HYDROGEN JET†

Progress is reported on the production of an intense polarized atomic hydrogen beam using microwave driven extraction of stabilized atomic hydrogen

Bcl-2 is a therapeutic target for hypodiploid b-lineage acute lymphoblastic leukemia

Acute lymphoblastic leukemia (ALL) is the most common cancer in children. The highest rates of treatment failure occur in specific genetic subsets of ALL, including hypodiploid B-cell ALL (B-ALL), for which effective alternative therapies to current intensive chemotherapy treatments have yet to be developed. Here, we integrated biochemical and genomic profiling with functional drug assays to select effective agents with therapeutic potential against hypodiploid B-ALL. ABT-199, a selective Bcl-2 inhibitor, was effective in reducing leukemic burden in vitro and in vivo in patient-derived xenograft models of hypodiploid B-ALL. Daily oral treatment with ABT-199 significantly increased survival in xenografted mice. The unexpected efficacy of ABT-199 observed in hypodiploid leukemias lacking BIM expression (the major reported mediator of ABT-199-induced apoptosis) led us to investigate the mechanism of action of ABT-199 in the absence of BIM. Treatment with ABT-199 elicited responses in a dose-dependent manner, from cell-cycle arrest at low nanomolar concentrations to cell death at concentrations above 100 nmol/L. Collectively, these results demonstrate the efficacy of Bcl-2 inhibition and potential therapeutic strategy in hypodiploid B-ALL. SIGNIFICANCE: These results demonstrate the efficacy of ABT-199 in vivo and provide encouraging preclinical data of Bcl-2 as a potential target for the treatment of hypodiploid B-ALL.Ernesto Diaz-Flores, Evan Q. Comeaux, Kailyn L. Kim, Ella Melnik, Kyle Beckman, Kara L. Davis, Kevin Wu, Jon Akutagawa, Olga Bridges, Roberta Marino, Margo Wohlfeil, Benjamin S. Braun, Charles G. Mullighan and Mignon L. Lo

Λc+ Production and Baryon-to-Meson Ratios in pp and p-Pb Collisions at √sNN=5.02 TeV at the LHC

The prompt production of the charm baryon Λ+c and the Λ+c/D0 production ratios were measured at midrapidity with the ALICE detector in pp and p-Pb collisions at √sNN=5.02 TeV. These new measurements show a clear decrease of the Λ+c/D0 ratio with increasing transverse momentum (pT) in both collision systems in the range 2<pT<12 GeV/c, exhibiting similarities with the light-flavor baryon-to-meson ratios p/π and Λ/K0S. At low pT, predictions that include additional color-reconnection mechanisms beyond the leading-color approximation, assume the existence of additional higher-mass charm-baryon states, or include hadronization via coalescence can describe the data, while predictions driven by charm-quark fragmentation processes measured in e+e− and e−p collisions significantly underestimate the data. The results presented in this Letter provide significant evidence that the established assumption of universality (colliding-system independence) of parton-to-hadron fragmentation is not sufficient to describe charm-baryon production in hadronic collisions at LHC energies.publishedVersio