Antiviral treatments targeting the coronavirus disease 2019 are urgently required. We screened a panel of already-approved drugs in a cell culture model of severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) and identified two new agents having higher antiviral potentials than the drug candidates such as Remdesivir and Chroloquine in VeroE6/TMPRSS2 cells: the anti-inflammatory drug Cepharanthine and HIV protease inhibitor Nelfinavir. Cepharanthine inhibited SARS-CoV-2 entry through the blocking of viral binding to target cells, whilst Nelfinavir suppressed viral replication partly by protease inhibition. Consistent with their different modes of action, synergistic effect of this combined treatment to limit SARS-CoV-2 proliferation was highlighted. Mathematical modeling in vitro antiviral activity coupled with the calculated total drug concentrations in the lung predicts that Nelfinavir will shorten the period until viral clearance by 4.9-days and the combining Cepharanthine/Nelfinavir enhanced their predicted efficacy. These results warrant further evaluation of the potential anti-SARS-CoV-2 activity of Cepharanthine and Nelfinavir.

key variables: leaf appearance rate, leaf elongation rate, and leaf lifespan. The expression of each of these traits is Quantitative trait loci (QTLs) for a number of agronomically imunder both genetic and environmental control (Lemaire portant traits of perennial ryegrass (Lolium perenne L.) were identiand Chapman, 1996), and leaf development in Lolium fied by means of a reference molecular marker-based genetic map. Replicated phenotypic data was obtained for a number of field-assessed has been demonstrated to be under genetic control in a morphological and developmental traits as well as the winter hardinumber of studies (Edwards and Cooper, 1963; Rhodes, ness-associated characters of winter survival and electrical conductiv-1973; Hazard et al., 1996). Structural characteristics of ity. Marker-trait association analysis was performed by a number of plants such as tiller number, leaf number, and leaf size methods, and a high degree of congruence was observed between the are the result of these morphogenetic traits, and their respective results. QTLs were detected for morphological traits such measurement in breeding programs allows a dissection as plant height, tiller size, leaf length, leaf width, fresh weight at of the complex herbage yield trait as well as predictions harvest, plant type, spikelet number per spike and spike length, as well of the response to grazing. as the developmental traits of heading date and degree of aftermath Different ecoclimatic regions, or pastures under difheading. A number of traits were significantly correlated, and coinciferent grazing regimes, may provide alternative selecdent QTL locations were identified. No significant QTLs for winter survival in the field were identified. However, a QTL for electrical

Background: Abnormal accumulation of mutant FUS/TLS is a pathological change in patients with amyotrophic lateral sclerosis (ALS). Results: A pathogenic mutation, G156E, increases propensities of FUS/TLS for aggregation in vitro and in vivo. Conclusion: Intranuclear aggregation of mutant FUS/TLS is a molecular pathomechanism of ALS. Significance: A loss of functional TLS/FUS in the nucleus will lead to neurodegeneration.

Tetramer formation of p53 is essential for its tumor suppressor function. p53 not only acts as a tumor suppressor protein by inducing cell cycle arrest and apoptosis in response to genotoxic stress, but it also regulates other cellular processes, including autophagy, stem cell self-renewal, and reprogramming of differentiated cells into stem cells, immune system, and metastasis. More than 50% of human tumors have TP53 gene mutations, and most of them are missense mutations that presumably reduce tumor suppressor activity of p53. This review focuses on the role of the tetramerization (oligomerization), which is modulated by the protein concentration of p53, posttranslational modifications, and/or interactions with its binding proteins, in regulating the tumor suppressor function of p53. Functional control of p53 by stabilizing or inhibiting oligomer formation and its bio-applications are also discussed. © 2015 Wiley Periodicals, Inc. Biopolymers (Pept Sci) 106: 598-612, 2016.

The tumor suppressor p53, a 393-amino acid transcription factor, induces cell cycle arrest and apoptosis in response to genotoxic stress. Its inactivation via the mutation of its gene is a key step in tumor progression, and tetramer formation is critical for p53 post-translational modification and its ability to activate or repress the transcription of target genes vital in inhibiting tumor growth. About 50% of human tumors have TP53 gene mutations; most are missense ones that presumably lower the tumor suppressor activity of p53. In this study, we explored the effects of known tumor-derived missense mutations on the stability and oligomeric structure of p53; our comprehensive, quantitative analyses encompassed the tetramerization domain peptides representing 49 such substitutions in humans. Their effects on tetrameric structure were broad, and the stability of the mutant peptides varied widely (⌬T m ‫؍‬ 4.8 ϳ ؊46.8°C). Because formation of a tetrameric structure is critical for protein-protein interactions, DNA binding, and the post-translational modification of p53, a small destabilization of the tetrameric structure could result in dysfunction of tumor suppressor activity. We suggest that the threshold for loss of tumor suppressor activity in terms of the disruption of the tetrameric structure of p53 could be extremely low. However, other properties of the tetramerization domain, such as electrostatic surface potential and its ability to bind partner proteins, also may be important.

Potently neutralizing SARS-CoV-2 antibodies often target the spike protein receptor binding site (RBS), but the variability of RBS epitopes hampers broad neutralization of multiple sarbecoviruses and drifted viruses. Here, using humanized mice, we identified an RBS antibody with a germline V H gene that potently neutralized SARS-related coronaviruses including SARS-CoV and SARS-CoV-2 variants. X-ray crystallography revealed coordinated recognition by the heavy chain of non-RBS conserved sites and the light chain of RBS with a binding angle mimicking the ACE2 receptor. The minimum footprints in the hypervariable region of RBS contributed to the breadth of neutralization, which was enhanced by IgG3 class switching. The coordinated binding resulted in broad neutralization of SARS-CoV and emerging SARS-CoV-2 variants of concern. Low dose therapeutic antibody treatment in hamsters reduced the virus titers and morbidity during SARS-CoV-2 challenge. The structural basis for broadly neutralizing activity may inform the design of broad spectrum of therapeutics and vaccines.

Misfolding of Cu,Zn-superoxide dismutase (SOD1) is a pathological change in the familial form of amyotrophic lateral sclerosis caused by mutations in the SOD1 gene. SOD1 is an enzyme that matures through the binding of copper and zinc ions and the formation of an intramolecular disulfide bond. Pathogenic mutations are proposed to retard the post-translational maturation, decrease the structural stability, and hence trigger the misfolding of SOD1 proteins. Despite this, a misfolded and potentially pathogenic conformation of immature SOD1 remains obscure. Here, we show significant and distinct conformational changes of apoSOD1 that occur only upon reduction of the intramolecular disulfide bond in solution. In particular, loop regions in SOD1 lose their restraint and become significantly disordered upon dissociation of metal ions and reduction of the disulfide bond. Such drastic changes in the solution structure of SOD1 may trigger misfolding and fibrillar aggregation observed as pathological changes in the familial form of amyotrophic lateral sclerosis.Mutations in Cu,Zn-superoxide dismutase (SOD1) 2 are linked to familial forms of amyotrophic lateral sclerosis (fALS) (1). A major pathological change observed in SOD1-related fALS is the abnormal accumulation of misfolded mutant SOD1 proteins in affected motor neurons (2). Actually, many in vivo as well as in vitro studies have supported that pathogenic mutations facilitate the misfolding of SOD1 proteins (3); however, the molecular mechanism triggering the misfolding of SOD1 remains controversial.SOD1 is known as one of the most stable proteins to the extent that its melting temperature (T m ) is Ͼ90°C (4); therefore, a misfolding event appears quite unlikely for SOD1. Nonetheless, SOD1 was found to have acquired such high stability through several post-translational processes including copper and zinc binding and disulfide bond formation (Fig. 1A). Actually, disulfide-reduced apoSOD1 exhibits significantly decreased stability (T m ϳ 42°C) and is susceptible to unfolding/ misfolding at physiological temperatures (5, 6). Intracellular deregulation of metal binding and/or disulfide formation will, hence, be a key event triggering the misfolding of SOD1.Notably, many pathogenic mutations are found to disturb the post-translational control of SOD1 maturation (7, 8) and thereby increase intracellular fractions of the apo-(9) and/or disulfide-reduced state (10). Only when both metal ions and disulfide bond are absent, SOD1 forms fibrillar aggregates (11). Given that SOD1 fibrillation is a pathological hallmark in SOD1-related fALS patients (12) as well as model mice (13), the most immature form of SOD1 will provide a clue to understand the molecular pathomechanism of this devastating disease. In a number of previous studies, the roles of metal binding and disulfide formation in the misfolding of SOD1 have been suggested by a variety of experimental methods (6, 8, 11, 14 -19); however, conformational information on SOD1 in solution lacking both metal ions and the disulfi...

No abstract