Summary
Deinococcus spp are among the most radiation‐resistant micro‐organisms that have been discovered. They show remarkable resistance to a range of damage caused by ionizing radiation, ...desiccation, UV radiation and oxidizing agents. Traditionally, Escherichia coli and Saccharomyces cerevisiae have been the two platforms of choice for engineering micro‐organisms for biotechnological applications, because they are well understood and easy to work with. However, in recent years, researchers have begun using Deinococcus spp in biotechnologies and bioremediation due to their specific ability to grow and express novel engineered functions. More recently, the sequencing of several Deinococcus spp and comparative genomic analysis have provided new insight into the potential of this genus. Features such as the accumulation of genes encoding cell cleaning systems that eliminate organic and inorganic cell toxic components are widespread among Deinococcus spp. Other features such as the ability to degrade and metabolize sugars and polymeric sugars make Deinococcus spp. an attractive alternative for use in industrial biotechnology.
Antisense oligomers constitute an attractive class of specific tools for genetic analysis and for potential therapeutic applications. Targets with different cellular locations have been described, ...such as mRNA translation initiation sites, pre-mRNA splicing sites, or the genes themselves. However the mechanism(s) of action and the intracellular distribution of antisense oligomers remain poorly understood. Antisense oligomers conjugated with various fluorochromes or with BrdUrd were microinjected into the cytoplasm of somatic cells, and their cellular distribution was monitored by fluorescence microscopy in fixed and nonfixed cells. A fast translocation in the nuclei and a concentration on nuclear structures were observed whatever probe was used. Nuclear transport occurs by diffusion since it is not affected by depletion of the intracellular ATP pool, temperature, or excess unlabeled oligomer. Accumulation of the oligomers in the nuclei essentially takes place on a set of proteins preferentially extracted between 0.2 M and 0.4 M NaCl as revealed by crosslinking of photosensitive oligomers. The relationship between nuclear location of antisense oligomers and their mechanism of action remains to be ascertained and could be of major interest in the design of more efficient antisense molecules.
Progress in targeting bacterial transcription Villain-Guillot, Philippe; Bastide, Lionel; Gualtieri, Maxime ...
Drug discovery today,
03/2007, Letnik:
12, Številka:
5
Journal Article
Recenzirano
The bacterial RNA polymerase (RNAP) is an essential enzyme that is responsible for making RNA from a DNA template and is targeted by several antibiotics. Rifampicin was the first of such antibiotics ...to be described and is one of the most efficient anti-tuberculosis drugs in use. In the past five years, structural studies of bacterial RNAP and the resolution of several complexes of drugs bound to RNAP subunits have revealed molecular details of the drug-binding sites and the mechanism of drug action. This knowledge opens avenues for the development of antibiotics. Here these drugs are reviewed, together with their mechanisms and their potential interest for therapeutic applications.
To discuss perioperative complications associated with the bone-anchored hearing aid (BAHA) and their management.
A retrospective review of 58 patients who underwent implantation of BAHA for ...unilateral conductive, mixed, or sensorineural hearing losses was performed at a tertiary referral center.
Between September 2003 and June 2005, 58 patients underwent implantation of a BAHA. There were 30 female and 28 male patients, with a mean age of 48 years (range 8-80 years). Complications occurred in 19% (11/58) of patients. Most adverse events were seen early in the series. The most common complication, partial or complete loss of the skin graft, occurred in 10% (6/58) of patients. These were managed successfully with local wound care. Five percent (3/58) of patients had skin growth over the abutment. Two of these cases were managed with office debridement, whereas 1 patient required revision under general anesthesia. There was implant extrusion in 3% (2/58) of patients, and both of these patients later underwent successful reimplantation. All patients had their implant activated 3 months after surgery. There were no perioperative or postoperative deaths.
Complications related to BAHA implantation are relatively minor and usually involve partial or complete loss of the skin graft. Most complications were successfully managed in the office.
The dramatic rise of antibiotic-resistant bacteria over the past two decades has stressed the need for completely novel classes of antibacterial agents. Accordingly, recent advances in the study of ...prokaryotic transcription open new opportunities for such molecules. This paper reports the structure−activity relationships of a series of phenyl-furanyl-rhodanines (PFRs) as antibacterial inhibitors of RNA polymerase (RNAP). The molecules have been evaluated for their ability to inhibit transcription and affect growth of bacteria living in suspension or in a biofilm and for their propensity to interact with serum albumin, a critical parameter for antibacterial drug discovery. The most active of these molecules inhibit Escherichia coli RNAP transcription at concentrations of ≤10 μM and have promising activities against various Gram-positive pathogens including Staphylococcus epidermidis biofilms, a major cause of nosocomial infection.
Ribosome profiling has revealed pervasive but largely uncharacterized translation outside of canonical coding sequences (CDSs). In this work, we exploit a systematic CRISPR-based screening strategy ...to identify hundreds of noncanonical CDSs that are essential for cellular growth and whose disruption elicits specific, robust transcriptomic and phenotypic changes in human cells. Functional characterization of the encoded microproteins reveals distinct cellular localizations, specific protein binding partners, and hundreds of microproteins that are presented by the human leukocyte antigen system. We find multiple microproteins encoded in upstream open reading frames, which form stable complexes with the main, canonical protein encoded on the same messenger RNA, thereby revealing the use of functional bicistronic operons in mammals. Together, our results point to a family of functional human microproteins that play critical and diverse cellular roles.
Islet amyloid is a characteristic feature of type 2 diabetes. Its major component is the normal beta-cell secretory product amylin, or islet amyloid polypeptide (IAPP). To determine whether increased ...or disproportionate release of amylin may explain the propensity for amyloid deposition in type 2 diabetes, we measured plasma amylin-like immunoreactivity (ALI) and immunoreactive insulin (IRI) release in response to an oral glucose load in 94 Japanese-American subjects with normal glucose tolerance (NGT; n=56), impaired glucose tolerance (IGT; n=10), and type 2 diabetes (n=28) as defined by World Health Organization criteria. The incremental increase in ALI, IRI, and glucose (G) at 30 min after oral glucose ingestion was used to calculate deltaALI/deltaG and deltaIRI/deltaG as measures of beta-cell function. Overall glucose metabolism was assessed as the incremental glucose area (glucose AUC) during the 2 h of the oral glucose tolerance test. As expected, plasma glucose concentrations at both fasting (NGT, 5.0+/-0.4; IGT, 5.5+/-0.1; type 2 diabetes, 6.2+/-0.3 mmol/l; P < 0.0001) and 2 h (NGT, 6.7+/-0.1; IGT, 9.4+/-0.3; type 2 diabetes, 13.2 +/-0.5 mmol/l; P < 0.0001) were elevated in individuals with IGT and type 2 diabetes. In response to glucose ingestion, plasma IRI and ALI increased in all subjects, but these increments were lower in individuals with reduced glucose tolerance, as reflected in the deltaIRI/deltaG (NGT, 119+/-10.3; IGT, 60.7+/-7.1; type 2 diabetes, 49.7 +/-5.4 pmol/l; P < 0.0001) and deltaALI/deltaG (NGT, 2.6+/-0.2; IGT, 1.8+/-0.3; type 2 diabetes, 1.2+/-0.1 pmol/l; P < 0.0001). Moreover, these reductions in the 30-min incremental ALI and IRI responses were proportionate such that the molar ratio of ALI to IRI was not different among the three groups (NGT, 2.6+/-0.2; IGT, 2.9 +/-0.3; type 2 diabetes, 2.9+/-0.3%; NS). Further, the relationship between beta-cell function, measured as either deltaIRI/deltaG or deltaALI/deltaG, and glucose metabolism, assessed as glucose AUC, was nonlinear and inverse in nature, with r2 values of 0.38 (P < 0.0001) and 0.33 (P < 0.0001), respectively. We conclude that the reduced beta-cell function of IGT and type 2 diabetes includes proportionate reductions in both IRI and ALI release. Thus, it is unlikely that the development of islet amyloid in type 2 diabetes is the result of increased release of ALI.
We have developed a multiwell assay for the detection of modulators of prokaryotic transcription based on the quantification of protein-protein interaction. This assay consists of three steps: (a) ...the immobilization of the Escherichia coli protein sigma70 in the well, (b) the incubation of the immobilized protein with core RNA polymerase and a potential inhibitor, and (c) washing and quantification of the binding of core to sigma70 with a monoclonal antibody conjugated to horseradish peroxidase. We show that this assay is sensitive, reproducible, and robust, and is able to discriminate between control competitors with different affinities. We demonstrate the usefulness of the assay to screen for microbial RNA polymerase inhibitors as potential new drugs for the treatment of emerging antibiotic-resistant bacteria.
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