Organizing signal transduction through A-kinase anchoring proteins (AKAPs)

A fundamental role for protein-protein interactions in the organization of signal transduction pathways is evident. Anchoring, scaffolding and adapter proteins function to enhance the precision and directionality of these signaling events by bringing enzymes together. The cAMP signaling pathway is organized by A-kinase anchoring proteins. This family of proteins assembles enzyme complexes containing the cAMP-dependent protein kinase, phosphoprotein phosphatases, phosphodiesterases and other signaling effectors to optimize cellular responses to cAMP and other second messengers. Selected A-kinase anchoring protein signaling complexes are highlighted in this minireview.     

Unbiased Characterization of Anopheles Mosquito Blood Meals by Targeted High-Throughput Sequencing

Understanding mosquito host choice is important for assessing vector competence or identifying disease reservoirs. Unfortunately, the availability of an unbiased method for comprehensively evaluating the composition of insect blood meals is very limited, as most current molecular assays only test for the presence of a few pre-selected species. These approaches also have limited ability to identify the presence of multiple mammalian hosts in a single blood meal. Here, we describe a novel high-throughput sequencing method that enables analysis of 96 mosquitoes simultaneously and provides a comprehensive and quantitative perspective on the composition of each blood meal. We validated in silico that universal primers targeting the mammalian mitochondrial 16S ribosomal RNA genes (16S rRNA) should amplify more than 95% of the mammalian 16S rRNA sequences present in the NCBI nucleotide database. We applied this method to 442 female Anopheles punctulatus s. l. mosquitoes collected in Papua New Guinea (PNG). While human (52.9%), dog (15.8%) and pig (29.2%) were the most common hosts identified in our study, we also detected DNA from mice, one marsupial species and two bat species. Our analyses also revealed that 16.3% of the mosquitoes fed on more than one host. Analysis of the human mitochondrial hypervariable region I in 102 human blood meals showed that 5 (4.9%) of the mosquitoes unambiguously fed on more than one person. Overall, analysis of PNG mosquitoes illustrates the potential of this approach to identify unsuspected hosts and characterize mixed blood meals, and shows how this approach can be adapted to evaluate inter-individual variations among human blood meals. Furthermore, this approach can be applied to any disease-transmitting arthropod and can be easily customized to investigate non-mammalian host sources.     

Organ-distribution of the metabolite 2-aminothiazoline-4-carboxylic acid in a rat model following cyanide exposure

The reaction of cyanide (CN(-)) with cystine to produce 2-aminothiazoline-4-carboxylic acid (ATCA) is one of the independent detoxification pathways of cyanide in biological systems. In this report, in vivo production of ATCA and its distributions in plasma and organs were studied after a subcutaneous sublethal dose of 4?mg/kg body weight potassium cyanide (KCN) administration to rats. At this sublethal dose of KCN, ATCA concentration was not significantly increased in the plasma samples, however, it was found significantly increased in liver samples. These results suggested that ATCA might not be a good diagnostic biomarker in plasma for sublethal cyanide exposure; however, liver could serve as the right organ for the detection of ATCA in post-mortem examinations involving cyanide exposure in military, firefighting, industrial and forensic settings.     

Nucleosides/Tides Abstracts

Abstract

Glycosyl Isothiocyanates: A New Synthetic Procedure     

Fertility of ewes following artificial insemination with semen frozen in pellets or straws, a preliminary report

In two trials involving the artificial insemination of 194 ewes, the fertility of ram semen was examined following freezing, either in pellet form or in straws, and after storage in a chilled state (15 degrees C) for up to 16 hours. Estrus was synchronized in ewes by intravaginal sponge (MAP) treatment for 14 days. At sponge removal 600 IU PMSG was injected and the ewes received two inseminations 50 and 60 hours later. Fertility was assessed at lambing. In trial 1, the mean lambing rate of 52% (16 31 ) for semen frozen in pellets was higher than 29% (9 31 ) for semen frozen in straws but this difference was not significant. In trial 2, ewes inseminated with chilled semen and semen frozen in pellets had lambing rates of 83% (44 53 ) and 55% (44 79 ) respectively (P<0.001).     

A fungal phylogeny based on 42 complete genomes derived from supertree and combined gene analysis

Background  

To date, most fungal phylogenies have been derived from single gene comparisons, or from concatenated alignments of a small number of genes. The increase in fungal genome sequencing presents an opportunity to reconstruct evolutionary events using entire genomes. As a tool for future comparative, phylogenomic and phylogenetic studies, we used both supertrees and concatenated alignments to infer relationships between 42 species of fungi for which complete genome sequences are available.     

Characterization of antimicrobial susceptibility and virulence genes of Salmonella serovars collected at a commercial turkey processing plant

Aims:  To determine the antimicrobial susceptibility profiles, distribution of class 1 integrons, virulence genes and genes encoding resistance to tetracycline ( tetA , tetC , tetD and tetE ) and streptomycin ( strA , strB and aadA1 ) in Salmonella recovered from turkeys.
Methods and Results:  The antimicrobial susceptibility of 80 isolates was determined using National Antimicrobial Resistance Monitoring System. The distribution of resistance genes, class 1 integrons and virulence genes was determined using PCR. Resistances to tetracycline (76·3%) and streptomycin (40%) were common. Sixty-two (77·5%) isolates displayed resistance against one or more antimicrobials and 33 were multi-drug resistant. tetA was detected in 72·5% of the isolates, while tetC , tetD and tetE were not detected. The strA and strB genes were detected in 73·8% of the isolates. Two isolates possessed class 1 integrons of 1 kb in size, containing the aadA1 gene conferring resistance to streptomycin and spectinomycin. Fourteen of the virulence genes were detected in over 80% of the isolates.
Conclusions:  This study shows that continuous use of tetracycline and streptomycin in poultry production selects for resistant strains. The Salmonella isolates recovered possess significant ability to cause human illness.
Significance and Impact of the Study:  Information from this study can be employed in guiding future strategies for the use of antimicrobials in poultry production.     

AIR: A batch-oriented web program package for construction of supermatrices ready for phylogenomic analyses

Background  

Large multigene sequence alignments have over recent years been increasingly employed for phylogenomic reconstruction of the eukaryote tree of life. Such supermatrices of sequence data are preferred over single gene alignments as they contain vastly more information about ancient sequence characteristics, and are thus more suitable for resolving deeply diverging relationships. However, as alignments are expanded, increasingly numbers of sites with misleading phylogenetic information are also added. Therefore, a major goal in phylogenomic analyses is to maximize the ratio of information to noise; this can be achieved by the reduction of fast evolving sites.     

A study of the growth kinetics of Yersinia enterocolitica serotype O:3 in pure and meat culture systems

The growth kinetics of a virulence plasmid-bearing (P+) and a plasmid-cured (P−) strain of Yersinia enterocolitica serotype O:3 in pure and meat culture were investigated. Growth studies were carried out at 25 and 37 °C in supplemented phosphate-buffered saline, buffered peptone water , cefsulodin-irgasan-novobiocin broth base or supplemented broth base (CIN). The lag phase durations and growth rates under these conditions were determined by linear regression analysis. In pure culture, under most sets of equivalent conditions, P+ and P− strains had similar lag phase durations. However, under one set of conditions, i.e. CIN broth at 37 °C, the lag phase duration of the P+ strain was significantly longer than P−. In all but the most selective medium, P+ strains had slower growth rates than P− strains at 37 °C, probably due to the increased metabolic burden entailed in the maintenance of the virulence plasmid. In the most selective medium, i.e. CIN broth, P+ strains grew significantly faster than P−. This finding suggests that possession of virulence plasmid confers an enhanced ability to grow in the presence of selective agents. In meat cultures, both strains had longer lag phases than in equivalent pure cultures, with longer lag phases noted at 37 than at 25 °C. No significant differences were observed between the length of lag phases of P+ and P− strains in meat culture. Both strains of Y. enterocolitica displayed faster growth rates in meat cultures than in pure cultures, indicating that one or more components of meat enhanced the growth of this organism. The effects and interaction of incubation temperature, enrichment broth and meat on the growth kinetics of plasmid-bearing and plasmid-cured Y. enterocolitica strains are discussed.