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991.
Recent Quaternary geological and climate events have shaped the evolutionary histories of plant species in the Mediterranean basin, one of the most important hotspots of biodiversity. Genetic analyses of the western Mediterranean Cheirolophus intybaceus s.l. (Asteraceae) based on AFLP were conducted to establish the relationships between its close species and populations, to reconstruct the phylogeography of the group and to analyse potential unidirectional versus bidirectional dispersals between the Ibero‐Provençal belt and the Balearic Islands. AFLP data revealed two main genetic groups, one constituted by the Balearic populations and Garraf (NE Iberia) and the other formed by the remaining mainland populations that were further sub‐structured into two geographically separated subgroups (SE + E Iberia and NE Iberia + SW France). Genetic diversity and spatial structure analyses suggested a mid‐Pleistocene scenario for the origin of C. intybaceus in southern Iberia, followed by dispersal to the north and a single colonisation event of the Balearic archipelago from the near Dianic NE Iberian area. This hypothesis was supported by paleogeographic data, which showed the existence of terrestrial connections between the continent and the islands during the Middle–Late Pleistocene marine regressions, whereas the more recent single back‐colonisation of the mainland from Mallorca might be explained by several hypotheses, such as long‐distance dispersal mediated by migratory marine birds or sea currents.  相似文献   
992.
Secretion of interferons (IFNs) from virus-infected cells is a hallmark of host antiviral immunity and in fact, IFNs exert their antiviral activities through the induction of antiviral proteins. The IFN-induced protein with tetratricopeptide repeats (IFITs) family is among hundreds of IFN-stimulated genes. This family contains a cluster of duplicated loci. Most mammals have IFIT1, IFIT2, IFIT3 and IFIT5; however, bird, marsupial, frog and fish have only IFIT5. Regardless of species, IFIT5 is always adjacent to SLC16A12. IFIT family genes are predominantly induced by type I and type III interferons and are regulated by the pattern recognition and the JAK-STAT signaling pathway. IFIT family proteins are involved in many processes in response to viral infection. However, some viruses can escape the antiviral functions of the IFIT family by suppressing IFIT family genes expression or methylation of 5'' cap of viral molecules. In addition, the variants of IFIT family genes could significantly influence the outcome of hepatitis C virus (HCV) therapy. We believe that our current review provides a comprehensive picture for the community to understand the structure and function of IFIT family genes in response to pathogens in human, as well as in animals.  相似文献   
993.
994.
The Sorcerer II is the highly mediatized and spectacular Venter Institute's ship that circumnavigated the planet between 2003 and 2006 to collect and classify marine microbial genomes. We analyze Craig Venter's public communication activities and strategies especially focusing on the images of science and scientist he proposes: that of an eighteenth-century “savant” and nineteenth-century naturalist devoted to the exploration of new worlds, and that of the hacker, hero of informational capitalism. Emphasizing his independence from both academy and industry, but building strong alliances with both spheres and with the media, Craig Venter sails the oceans of the contemporary biotechnologies' market, interpreting a specific typology of the relationship between science and society, enterprises, universities.  相似文献   
995.
Recent developments of tools for targeted genome modification have led to new concepts in how multiple traits can be combined. Targeted genome modification is based on the use of nucleases with tailor‐made specificities to introduce a DNA double‐strand break (DSB) at specific target loci. A re‐engineered meganuclease was designed for specific cleavage of an endogenous target sequence adjacent to a transgenic insect control locus in cotton. The combination of targeted DNA cleavage and homologous recombination–mediated repair made precise targeted insertion of additional trait genes (hppd, epsps) feasible in cotton. Targeted insertion events were recovered at a frequency of about 2% of the independently transformed embryogenic callus lines. We further demonstrated that all trait genes were inherited as a single genetic unit, which will simplify future multiple‐trait introgression.  相似文献   
996.
This review highlights recent advances in our understanding of the mechanisms of Optineurin (Optn) action and its implication in diseases. Optn has emerged as a key player regulating various physiological processes, including membrane trafficking, protein secretion, cell division and host defense against pathogens. Furthermore, there is growing evidence for an association of Optn mutations with human diseases such as primary open-angle glaucoma, amyotrophic lateral sclerosis and Paget’s disease of bone. Optn functions depend on its precise subcellular localization and its interaction with other proteins. Here, we review the mechanisms that allow Optn to ensure a timely and spatially coordinated integration of different physiological processes and discuss how their deregulation may lead to different pathologies.  相似文献   
997.
The 67 kDa laminin receptor (67LR), one of several cell surface laminin-binding proteins, is involved in the interactions between cancer cells and laminin during tumor invasion and metastasis. A 37 kDa polypeptide (37LRP), previously identified as the 67LR precursor, is abundantly present in the cytoplasm and has been implicated in polysome formation. To better understand the cellular localization of the 67LR and its precursor, transmission electron microscopic studies of human melanoma A2058 cells were carried out using immunogold labeling and a variety of antibodies: (a) affinity purified antibodies directed against 37LRP cDNA-derived synthetic peptides; (b) anti-67LR monoclonal antibodies raised against intact human small cell lung carcinoma cells; and (c) monoclonal antibodies against the subunits of the integrin laminin receptor, α6β1. Double-labeling immunocyto-chemistry revealed that anti-67LR monoclonal antibodies as well as anti-37 LRP antibodies recognized antigens that were localized in the cytoplasm in electron dense structures. As expected, cell membrane labeling was also observed. Surprisingly, α6 and β1 integrin subunits were detected in the same cytoplasmic structures positive for the 67LR and the 37LRP. After addition of soluble laminin to A2058 cells in suspension, the number of labeled cytoplasmic structures increased especially in the vicinity of the plasma membrane, and were exported onto the cell surface. Neither fibronectin nor BSA induced such an effect. The data demonstrate that the 67 LR and the 37 LRP antibodies detect colocalized antigens that are in cytoplasmic structures with α6β1 integrin. These laminin binding protein rich structures could potentially form a supply of receptors that are exported to the surface upon exposure of the cells to laminin, with a consequent increase in the number of binding sites for the ligand. This system could define a mechanism through which cancer cells modulate their interaction with laminin.  相似文献   
998.
999.
Head and neck squamous cell carcinoma (HNSCC) is the sixth leading cancer in the world; the main risk factors are alcohol and tobacco use. Advancements in therapies have yet to improve the prognosis of HNSCC. The connection between diabetes and cancer is being recognized, and metformin has been shown to decrease cancer incidence in diabetic patients. Accordingly, here, for the first time, we investigated metformin’s efficacy on the growth and viability of human HNSCC FaDU and Detroit cells. Our results show that metformin treatment (5–20 mM) dose-dependently inhibits the growth of both cell lines. In FaDU cells, metformin caused 18–57% and 35–81% growth inhibition after 48 and 72 h treatments, respectively. Similarly, in Detroit 562 cells, 48 and 72 h metformin treatment resulted in 20–57% and 33–82% inhibition, respectively. Mechanistically, metformin caused G1 arrest, which coincided with a decrease in the protein levels of CDKs (2, 4 and 6), cyclins (D1 and E) and CDK inhibitors (p15, p16, p18 and p27), but no change in p19 and p21. Metformin also decreased the levels of oncogenic proteins Skp2 and β-Trcp. In other studies, metformin decreased the phosphorylation of 4E-BP1 at Ser65, Thr37/46 and Thr70 sites, but drastically increased the phosphorylation of EF2 at Thr56 and AMPK at Thr172, which results in global translational inhibition. In summary, the observed wide spectrum of mechanistic effects of metformin on HNSCC cells provides support for the anticancer capability of the drug and its potential use in future therapies.  相似文献   
1000.
Optimization of biophysical properties is a critical success factor for the developability of monoclonal antibodies with potential therapeutic applications. The inter-domain disulfide bond between light chain (Lc) and heavy chain (Hc) in human IgG1 lends structural support for antibody scaffold stability, optimal antigen binding, and normal Fc function. Recently, human IgG1λ has been suggested to exhibit significantly greater susceptibility to reduction of the inter Lc-Hc disulfide bond relative to the same disulfide bond in human IgG1κ. To understand the molecular basis for this observed difference in stability, the sequence and structure of human IgG1λ and human IgG1κ were compared. Based on this Lc comparison, three single mutations were made in the λ Lc proximal to the cysteine residue, which forms a disulfide bond with the Hc. We determined that deletion of S214 (dS) improved resistance of the association between Lc and Hc to thermal stress. In addition, deletion of this terminal serine from the Lc of IgG1λ provided further benefit, including an increase in stability at elevated pH, increased yield from transient transfection, and improved in vitro antibody dependent cell-mediated cytotoxicity (ADCC). These observations support the conclusion that the presence of the terminal serine of the λ Lc creates a weaker inter-chain disulfide bond between the Lc and Hc, leading to slightly reduced stability and a potential compromise in IgG1λ function. Our data from a human IgG1λ provide a basis for further investigation of the effects of deleting terminal serine from λLc on the stability and function of other human IgG1λ antibodies.  相似文献   
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