Atomic structures and deletion mutant reveal different capsid-binding patterns and functional significance of tegument protein pp150 in murine and human cytomegaloviruses with implications for therapeutic development.

Cytomegalovirus (CMV) infection causes birth defects and life-threatening complications in immunosuppressed patients. Lack of vaccine and need for more effective drugs have driven widespread ongoing therapeutic development efforts against human CMV (HCMV), mostly using murine CMV (MCMV) as the model system for preclinical animal tests. The recent publication (Yu et al., 2017, DOI: 10.1126/science.aam6892) of an atomic model for HCMV capsid with associated tegument protein pp150 has infused impetus for rational design of novel vaccines and drugs, but the absence of high-resolution structural data on MCMV remains a significant knowledge gap in such development efforts. Here, by cryoEM with sub-particle reconstruction method, we have obtained the first atomic structure of MCMV capsid with associated pp150. Surprisingly, the capsid-binding patterns of pp150 differ between HCMV and MCMV despite their highly similar capsid structures. In MCMV, pp150 is absent on triplex Tc and exists as a "Λ"-shaped dimer on other triplexes, leading to only 260 groups of two pp150 subunits per capsid in contrast to 320 groups of three pp150 subunits each in a "Δ"-shaped fortifying configuration. Many more amino acids contribute to pp150-pp150 interactions in MCMV than in HCMV, making MCMV pp150 dimer inflexible thus incompatible to instigate triplex Tc-binding as observed in HCMV. While pp150 is essential in HCMV, our pp150-deletion mutant of MCMV remained viable though with attenuated infectivity and exhibiting defects in retaining viral genome. These results thus invalidate targeting pp150, but lend support to targeting capsid proteins, when using MCMV as a model for HCMV pathogenesis and therapeutic studies

The study of exotic state Zc±(3900)Z_c^{\pm}(3900) decaying to J/ψπ±J/\psi\pi^{\pm} in the pppp collisions at s\sqrt{s} = 1.96, 7, and 13 TeV

A dynamically constrained phase-space coalescence model plus PACIAE model was used to predict the exotic resonant state $Z_c^{\pm}(3900)$ yield, transverse momentum distribution, and the rapidity distribution with $|y| < 6$ and $p_T < 10$ GeV/c in $pp$ collisions at $\sqrt{s} = 1.96, 7$ and 13 TeV, respectively. The yield of the $Z_c^{\pm}(3900)$ is estimated to be around $10^{-6}$ to $10^{-5}$. We also present the energy dependence of the transverse momentum distributions and rapidity distributions for ${Z_c^{+}(3900)}$ and ${Z_c^{-}(3900)}$. The production of ${Z_c^{+}(3900)}$ and its anti-particle ${Z_c^{-}(3900)}$ is found to be quite similar to each other.Comment: 6 pages,5 figure

Integrated traditional Chinese and western medicine for Menopausal syndrome: Meta-analysis of randomized controlled trials

Background: To critically assess the evidence of integrated Chinese and western medicine for treating  Menopausal syndrome (MPS).Methods and Materials: A search across the Chinese Biomedical Medicine (CBM), Chinese National Knowledge Infrastructure (CNKI), VIP database (VIP), Wangfang database (Wanfang), PubMed and the Cochrane Library databases was conducted (up to October 31st, 2013) in commonly used integrated Chinese and western medicine therapies for menopausal syndrome. A number of Randomized Controlled Trials (RCTs) evaluating the therapeutic efficacy of integrated Chinese and western medicine in patients with PPS were included. The quality of the included studies was evaluated and a meta-analysis was performed using the RevMan5.0 software.Results: Twelve RCTs with 1155 patients were evaluated in this review. The results of meta-analysis showed that the therapy of using integrated Chinese and western medicine was significantly superior to that of western medicine alone towards improving the efficacy, relieving the clinical symptoms and decreasing follicle-stimulating hormone (FSH）levels (P&lt;0.05), even though the effects of two treatments were the same in regulating the levels of luteinizing hormone (LH) and estradiol (E2).Conclusion: Compared to a regular treatment with western medicine alone, the therapeutic approach that utilizes integration of Chinese with western medicine can effectively improve the clinical efficacy and serum hormone levels in patients with menopausal syndrome. However, the evidence was not very strong due to the poor quality of the included studies.Key words: Integrated Traditional Chinese and Western Medicine, Menopausal Syndrome, Meta-analysi

Cholesterol-binding site of the influenza M2 protein in lipid bilayers from solid-state NMR

The influenza M2 protein not only forms a proton channel but also mediates membrane scission in a cholesterol-dependent manner to cause virus budding and release. The atomic interaction of cholesterol with M2, as with most eukaryotic membrane proteins, has long been elusive. We have now determined the cholesterol-binding site of the M2 protein in phospholipid bilayers using solid-state NMR spectroscopy. Chain-fluorinated cholesterol was used to measure cholesterol proximity to M2 while sterol-deuterated cholesterol was used to measure bound-cholesterol orientation in lipid bilayers. Carbon–fluorine distance measurements show that at a cholesterol concentration of 17 mol%, two cholesterol molecules bind each M2 tetramer. Cholesterol binds the C-terminal transmembrane (TM) residues, near an amphipathic helix, without requiring a cholesterol recognition sequence motif. Deuterium NMR spectra indicate that bound cholesterol is approximately parallel to the bilayer normal, with the rough face of the sterol rings apposed to methyl-rich TM residues. The distance- and orientation-restrained cholesterol-binding site structure shows that cholesterol is stabilized by hydrophobic interactions with the TM helix and polar and aromatic interactions with neighboring amphipathic helices. At the 1:2 binding stoichiometry, lipid31P spectra show an isotropic peak indicative of high membrane curvature. This M2–cholesterol complex structure, together with previously observed M2 localization at phase boundaries, suggests that cholesterol mediates M2 clustering to the neck of the budding virus to cause the necessary curvature for membrane scission. The solid-state NMR approach developed here is generally applicable for elucidating the structural basis of cholesterol’s effects on membrane protein function. Keywords: membrane; ¹⁹F-NMR; deuterium NMR; docking; membrane scissio

A structural and mechanistic study of π-clamp-mediated cysteine perfluoroarylation

Natural enzymes use local environments to tune the reactivity of amino acid side chains. In searching for small peptides with similar properties, we discovered a four-residue π-clamp motif (Phe-Cys-Pro-Phe) for regio- and chemoselective arylation of cysteine in ribosomally produced proteins. Here we report mutational, computational, and structural findings directed toward elucidating the molecular factors that drive π-clamp-mediated arylation. We show the significance of a trans conformation prolyl amide bond for the π-clamp reactivity. The π-clamp cysteine arylation reaction enthalpy of activation (ΔH‡) is significantly lower than a non-π-clamp cysteine. Solid-state NMR chemical shifts indicate the prolyl amide bond in the π-clamp motif adopts a 1:1 ratio of the cis and trans conformation, while in the reaction product Pro3 was exclusively in trans. In two structural models of the perfluoroarylated product, distinct interactions at 4.7 Å between Phe1 side chain and perfluoroaryl electrophile moiety are observed. Further, solution 19F NMR and isothermal titration calorimetry measurements suggest interactions between hydrophobic side chains in a π-clamp mutant and the perfluoroaryl probe. These studies led us to design a π-clamp mutant with an 85-fold rate enhancement. These findings will guide us toward the discovery of small reactive peptides to facilitate abiotic chemistry in water.National Institutes of Health (U.S.) (Grant R01GM110535)National Institutes of Health (U.S.) (Grant GM088204)National Science Foundation (U.S.) (Award CHE-1464804

Co-expression of the Arabidopsis SOS genes enhances salt tolerance in transgenic tall fescue (Festuca arundinacea Schreb.)

Crop productivity is greatly affected by soil salinity; therefore, improvement in salinity tolerance of crops is a major goal in salt-tolerant breeding. The Salt Overly Sensitive (SOS) signal-transduction pathway plays a key role in ion homeostasis and salt tolerance in plants. Here, we report that overexpression of Arabidopsis thaliana SOS1+SOS2+SOS3 genes enhanced salt tolerance in tall fescue. The transgenic plants displayed superior growth and accumulated less Na(+) and more K(+) in roots after 350 mM NaCl treatment. Moreover, Na(+) enflux, K(+) influx, and Ca(2+) influx were higher in the transgenic plants than in the wild-type plants. The activities of the enzyme superoxide dismutase, peroxidase, catalase, and proline content in the transgenic plants were significantly increased; however, the malondialdehyde content decreased in transgenic plants compared to the controls. These results suggested that co-expression of A. thaliana SOS1+SOS2+SOS3 genes enhanced the salt tolerance in transgenic tall fescue. ELECTRONIC SUPPLEMENTARY MATERIAL: The online version of this article (doi:10.1007/s00709-013-0540-9) contains supplementary material, which is available to authorized users