The large French research project GENIUS (2012–2019, https://www6.inra.genius-project_eng/) provides a good showcase of current genome editing techniques applied to crop plants. It addresses a large variety of agricultural species (rice, wheat, maize, tomato, potato, oilseed rape, poplar, apple and rose) together with some models (Arabidopsis, Brachypodium, Physcomitrella). Using targeted mutagenesis as its work horse, the project is limited to proof of concept under confined conditions. It mainly covers traits linked to crop culture, such as disease resistance to viruses and fungi, flowering time, plant architecture, tolerance to salinity and plant reproduction but also addresses traits improving the quality of agricultural products for industrial purposes. Examples include virus resistant tomato, early flowering apple and low-amylose starch potato. The wide range of traits illustrates the potential of genome editing towards a more sustainable agriculture through the reduction of pesticides and to the emergence of innovative bio-economy sectors based on custom tailored quality traits.
The role of the nuclear receptor FXR in adaptive thermogenesis was investigated using FXR-deficient mice. Despite elevated serum bile acid concentrations and increased mRNA expression profiles of thermogenic genes in brown adipose tissue, FXR-deficiency did not alter energy expenditure under basal conditions. However, FXR-deficiency accelerated the fasting-induced entry into torpor in a leptin-dependent manner. FXR-deficient mice were also extremely cold-intolerant. These altered responses may be linked to a more rapid decrease in plasma concentrations of metabolic fuels (glucose, triglycerides) thus impairing uncoupling protein 1-driven thermogenesis. These results identify FXR as a modulator of energy homeostasis. 相似文献
Profiling integral plasma membrane proteins is of particular importance for the identification of new biomarkers for diagnosis and for drug development. We report in this study the identification of surface markers by performing comparative proteomics of established human immunodeficiency virus-1 (HIV-1) latent cell models and parental cell lines. To this end we isolated integral membrane proteins using a biotin-directed affinity purification method. Isolated proteins were separated by two-dimensional gel electrophoresis and identified by matrix-assisted laser desorption/ionization-time-of-flight (MALDI-TOF) after in gel digestion. Seventeen different proteins were found to vary on the surface of T-cells due to HIV-1 infection. Of these proteins, 47% were integral membrane proteins, and 18% were membrane-associated. Through the use of complementary techniques such as Western blotting and fluorescent staining, we confirmed the differential expression of some of the proteins identified by MALDI-TOF including Bruton's tyrosine kinase and X-linked inhibitor of apoptosis. Finally, using phosphatidylinositol 3-kinase inhibitors and flavopiridol to inhibit Bruton's tyrosine kinase localization at the membrane and X-linked inhibitor of apoptosis protein expression, respectively, we showed that HIV-1 latently infected cells are more sensitive to these drugs than uninfected cells. This suggests that HIV-1 latently infected cells may be targeted with drugs that alter several pathways that are essential for the establishment and maintenance of latency. 相似文献
Phototropism, or the directional growth (curvature) of various organs toward or away from incident light, represents a ubiquitous adaptive response within the plant kingdom. This response is initiated through the sensing of directional blue light (BL) by a small family of photoreceptors known as the phototropins. Of the two phototropins present in the model plant Arabidopsis thaliana, phot1 (phototropin 1) is the dominant receptor controlling phototropism. Absorption of BL by the sensory portion of phot1 leads, as in other plant phototropins, to activation of a C-terminal serine/threonine protein kinase domain, which is tightly coupled with phototropic responsiveness. Of the five phot1-interacting proteins identified to date, only one, NPH3 (non-phototropic hypocotyl 3), is essential for all phot1-dependent phototropic responses, yet little is known about how phot1 signals through NPH3. Here, we show that, in dark-grown seedlings, NPH3 exists as a phosphorylated protein and that BL stimulates its dephosphorylation. phot1 is necessary for this response and appears to regulate the activity of a type 1 protein phosphatase that catalyzes the reaction. The abrogation of both BL-dependent dephosphorylation of NPH3 and development of phototropic curvatures by protein phosphatase inhibitors further suggests that this post-translational modification represents a crucial event in phot1-dependent phototropism. Given that NPH3 may represent a core component of a CUL3-based ubiquitin-protein ligase (E3), we hypothesize that the phosphorylation state of NPH3 determines the functional status of such an E3 and that differential regulation of this E3 is required for normal phototropic responsiveness. 相似文献
A procedure for the synthesis of a ratiometric viscosity fluorescent sensor is described in this protocol. The essential requirement for the design of this sensor is the attachment of a primary fluorophore that has both a viscosity-independent fluorescence emission (coumarin dye shown in blue) and an emission from a fluorophore that exhibits viscosity-dependent fluorescent quantum yield (p-amino cinnamonitrile dye shown in red). The use of sensor 1 in viscosity measurements involves solubilization in a liquid of interest and excitation of the primary fluorophore at lambda(ex) = 360 nm. The secondary fluorophore is simultaneously excited via resonance energy transfer. The ratio of the fluorescent emission of the secondary over the primary fluorophore provides a fast and precise measurement of the viscosity of the solvent. The synthesis of compound 1 using commercially available materials can be completed within 5 d. 相似文献
Infection by the bacterium Listeria monocytogenes depends on host cell clathrin. To determine whether this requirement is widespread, we analyzed infection models using diverse bacteria. We demonstrated that bacteria that enter cells following binding to cellular receptors (termed "zippering" bacteria) invade in a clathrin-dependent manner. In contrast, bacteria that inject effector proteins into host cells in order to gain entry (termed "triggering" bacteria) invade in a clathrin-independent manner. Strikingly, enteropathogenic Escherichia coli (EPEC) required clathrin to form actin-rich pedestals in host cells beneath adhering bacteria, even though this pathogen remains extracellular. Furthermore, clathrin accumulation preceded the actin rearrangements necessary for Listeria entry. These data provide evidence for a clathrin-based entry pathway allowing internalization of large objects (bacteria and ligand-coated beads) and used by "zippering" bacteria as part of a general mechanism to invade host mammalian cells. We also revealed a nonendocytic role for clathrin required for extracellular EPEC infections. 相似文献
Natural killer T (NKT) cells combine features of the innate and adaptive immune systems. Recently, it has become evident that these T cells have crucial roles in the response to infectious agents. The antigen receptor expressed by NKT cells directly recognizes unusual glycolipids that are part of the membrane of certain Gram-negative bacteria and spirochetes. Moreover, even in the absence of microbial glycolipid antigens, these T cells respond to innate cytokines produced by dendritic cells that have been activated by microbes. This indirect sensing of infection, by responding to cytokines from activated dendritic cells, allows NKT cells to react to a broad range of infectious agents. 相似文献