Calnexin family members as modulators of genetic diseases

The endoplasmic reticulum (ER) is an intracellular compartment devoted to the synthesis, segregation and folding of soluble and membrane secretory proteins. Some mutations in these proteins lead to their incorrect or incomplete folding in the ER. The ER has a quality control system which detects misfolded proteins and then specifies their fate. Some mutated proteins are retained in the ER wherein they accumulate (Russell bodies for misfolded immunoglobulin heavy chains, the PiZZ for alpha 1-antitrypsin), others are retrotranslocated from the ER and degraded by the cytosolic proteasomal system, and yet other proteins are eventually secreted (in AZC-treated cells). In this review we summarize the role of ER resident proteins in quality control of mutated secretory proteins.     

Agronomic,genetic and chemical tools for hop cultivation and breeding

Phytochemistry Reviews - Humulus lupulus L. (hop) is a dioecious climbing plant of which the females bear particular inflorescences, called hops, ‘cones’ or ‘strobiles’,...     

New chemical tools for investigating human mitotic kinesin Eg5

We have designed and synthesized a series of monastrol derivatives, an allosteric inhibitor of Eg5, a motor protein responsible for the formation and maintenance of the bipolar spindle in mitotic cells. Sterically demanding structural modifications have been introduced on the skeleton of the parent drug either via a multicomponent Biginelli reaction or a stepwise modification of monastrol. The ability of these compounds to inhibit Eg5 activity has been investigated using two in vitro steady-state ATPase assays (basal and microtubule-stimulated) as well as a cell-based assay. One compound in the series appeared more potent than monastrol by a fivefold factor. Three other compounds that were unable to inhibit Eg5 ATPase activity in vitro proved potent Eg5 inhibitors in the cell-based assay. The results obtained led to the identification of structure-activity relationships further used to design an affinity matrix that can be used for fast and efficient purification of Eg5 from crude lysate of eukaryotic cells.     

Nano-biophotonics: new tools for chemical nano-analytics

The nondestructive chemical analysis of biological processes in the crowded intracellular environment, at cellular membranes, and between cells with a spatial resolution well beyond the diffraction limit is made possible through Nano-Biophotonics. A number of sophisticated schemes employing nanoparticles, nano-apertures, or shaping of the probe volume in the far field have significantly extended our knowledge about lipid rafts, macromolecular complexes, such as chromatin, vesicles, and cellular organelles, and their interactions and trafficking within the cell. Here, I review some of the most recent developments in Nano-Biophotonics that already are or soon will become relevant to the analysis of intracellular processes. The pros and cons of the various techniques will be discussed and an outlook of their prospects for the near future will be provided.     

Bacteriophytochromes: new tools for understanding phytochrome signal transduction

The recent discovery of phytochrome-like photoreceptors, collectively called bacteriophytochromes, in a number of bacteria has greatly expanded our understanding of the origins and modes of action of phytochromes in higher plants. These primitive receptors contain an N-terminal domain homologous to the chromophore-binding pocket of phytochromes, and like phytochromes, they bind a variety of bilins to generate photochromic holoproteins. Following the chromophore pocket is a domain similar to two-component histidine kinases, suggesting that these bacterial photoreceptors function in phosphorelay cascades that respond to the light environment. Their organization and distribution support the views that higher-plant phytochromes evolved from a cyanobacterial precursor and that they act as light-regulated kinases. With the ability to exploit bacterial genetics, these bacteriophytochromes now offer simple models to help unravel the biochemical and biophysical events that initiate phytochrome signal transmission.     

Identification of genetic and chemical modulators of zebrafish mechanosensory hair cell death

Inner ear sensory hair cell death is observed in the majority of hearing and balance disorders, affecting the health of more than 600 million people worldwide. While normal aging is the single greatest contributor, exposure to environmental toxins and therapeutic drugs such as aminoglycoside antibiotics and antineoplastic agents are significant contributors. Genetic variation contributes markedly to differences in normal disease progression during aging and in susceptibility to ototoxic agents. Using the lateral line system of larval zebrafish, we developed an in vivo drug toxicity interaction screen to uncover genetic modulators of antibiotic-induced hair cell death and to identify compounds that confer protection. We have identified 5 mutations that modulate aminoglycoside susceptibility. Further characterization and identification of one protective mutant, sentinel (snl), revealed a novel conserved vertebrate gene. A similar screen identified a new class of drug-like small molecules, benzothiophene carboxamides, that prevent aminoglycoside-induced hair cell death in zebrafish and in mammals. Testing for interaction with the sentinel mutation suggests that the gene and compounds may operate in different pathways. The combination of chemical screening with traditional genetic approaches is a new strategy for identifying drugs and drug targets to attenuate hearing and balance disorders.     

Molecular tools for chemical biotechnology

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Solid-phase chemical tools for glycobiology

Techniques involving solid supports have played crucial roles in the development of genomics, proteomics, and in molecular biology in general. Similarly, methods for immobilization or attachment to surfaces and resins have become ubiquitous in sequencing, synthesis, analysis, and screening of oligonucleotides, peptides, and proteins. However, solid-phase tools have been employed to a much lesser extent in glycobiology and glycomics. This review provides a comprehensive overview of solid-phase chemical tools for glycobiology including methodologies and applications. We provide a broad perspective of different approaches, including some well-established ones, such as immobilization in microtiter plates and to cross-linked polymers. Emerging areas such as glycan microarrays and glycan sequencing, quantum dots, and gold nanoparticles for nanobioscience applications are also discussed. The applications reviewed here include enzymology, immunology, elucidation of biosynthesis, and systems biology, as well as first steps toward solid-supported sequencing. From these methods and applications emerge a general vision for the use of solid-phase chemical tools in glycobiology.     

Data processing and exchange tools to facilitate chemical genetic screening processes

Due to the development of chemical genomics, the screening of chemical libraries is used more and more by research laboratories to identify small molecule inhibitors or activators of cell functions. To facilitate the treatment and archiving of screening data, we developed a multiuser web application called Elisa Data Exchanger (EDE). The program is able to automatically identify which chemical compounds were tested. Several data exchange formats can be generated for visualization, printing, charting, or exporting to chemical analysis software. These data exchange functions allow for a comparison of results obtained from screening several targets in order to select the most specific compounds. EDE is freely available online at https://ibph.pharma.univ-montpl.fr/ede/ (login: evalede, password: loginede).     

离子通道与人类遗传病

细胞膜离子通道结构和功能正常是细胞进行生理活动的基础,对离子通道功能具有决定性意义的特定位点的突变导致其开放、关闭或激活、失活功能异常,引起组织机能紊乱,形成各种遗传性疾病。本文从水通道蛋白,钙通道,钠通道,钾通道等多种通道蛋白引起的遗传病的现象以及机理做较深入的阐述。     

Protein interactions in human genetic diseases

We present a novel method that combines protein structure information with protein interaction data to identify residues that form part of an interaction interface. Our prediction method can retrieve interaction hotspots with an accuracy of 60% (at a 20% false positive rate). The method was applied to all mutations in the Online Mendelian Inheritance in Man (OMIM) database, predicting 1,428 mutations to be related to an interaction defect. Combining predicted and hand-curated sets, we discuss how mutations affect protein interactions in general.     

Progress and promise in understanding the genetic basis of common diseases

Susceptibility to common human diseases is influenced by both genetic and environmental factors. The explosive growth of genetic data, and the knowledge that it is generating, are transforming our biological understanding of these diseases. In this review, we describe the technological and analytical advances that have enabled genome-wide association studies to be successful in identifying a large number of genetic variants robustly associated with common disease. We examine the biological insights that these genetic associations are beginning to produce, from functional mechanisms involving individual genes to biological pathways linking associated genes, and the identification of functional annotations, some of which are cell-type-specific, enriched in disease associations. Although most efforts have focused on identifying and interpreting genetic variants that are irrefutably associated with disease, it is increasingly clear that—even at large sample sizes—these represent only the tip of the iceberg of genetic signal, motivating polygenic analyses that consider the effects of genetic variants throughout the genome, including modest effects that are not individually statistically significant. As data from an increasingly large number of diseases and traits are analysed, pleiotropic effects (defined as genetic loci affecting multiple phenotypes) can help integrate our biological understanding. Looking forward, the next generation of population-scale data resources, linking genomic information with health outcomes, will lead to another step-change in our ability to understand, and treat, common diseases.