Sequential and structural homology between intracellular pathogenesis-related proteins and a group of latex proteins

The intracellular pathogenesis-related proteins have been identified in a broad range of flowering plants. Some display quite different patterns of expression, in many cases unrelated to the pathogenic response. Nevertheless, these proteins are all very similar and in most cases share more than 35% sequence identity. In this report we investigate the significance of a rather weak similarity between the intracellular pathogenesis-related (IPR or PR-10) proteins and a group of proteins identified in the latex of opium poppy and in Arabidopsis, among others. A sequence analysis held together with the recently published three-dimensional structure of Bet v 1, an IPR protein from birch pollen, strongly suggests sequential and structural homology between the two protein families.     

The evolution of body size in birds. II. The role of reproductive power

Given that body mass evolves non-randomly in birds, it is important to ask what factors might be responsible. One suggestion is that the rate at which individuals turn resources into offspring, termed reproductive power, might explain this non-randomness. This is because, in mammals, the body mass with the highest reproductive power is the most common (modal) one. Reproductive power was estimated for birds from data on energetic content of eggs and population productivity. According to the formulation of Brown et al. (1993), reproductive power is composed of two component processes: acquisition (acquiring resources and storing them in reproductive biomass) and conversion (converting reproductive biomass into offspring). As with mammals, estimates of reproductive power indicate that the most common body mass in birds is also the body mass that maximizes reproductive power. The relationship between reproductive power and diversity is different for species smaller than this modal body mass when compared to those that are larger. The relationship of body mass and reproductive power is different between birds and mammals in two ways: (1) the body mass that maximizes reproductive power is smaller in birds (33g) than in mammals (100g), and (2) mammals generate more reproductive power than an equivalent-sized bird. Reproductive power is determined primarily by acquisition in small birds and mammals, while it is determined by conversion in the largest birds and mammals. It is likely that reproductive power is closely tied to the evolution and diversification of body masses because it constrains the ways in which traits affecting fitness can evolve.     

A Novel Functional Human Eukaryotic Translation Initiation Factor 4G

Mammalian eukaryotic translation initiation factor 4F (eIF4F) is a cap-binding protein complex consisting of three subunits: eIF4E, eIF4A, and eIF4G. In yeast and plants, two related eIF4G species are encoded by two different genes. To date, however, only one functional eIF4G polypeptide, referred to here as eIF4GI, has been identified in mammals. Here we describe the discovery and functional characterization of a closely related homolog, referred to as eIF4GII. eIF4GI and eIF4GII share 46% identity at the amino acid level and possess an overall similarity of 56%. The homology is particularly high in certain regions of the central and carboxy portions, while the amino-terminal regions are more divergent. Far-Western analysis and coimmunoprecipitation experiments were used to demonstrate that eIF4GII directly interacts with eIF4E, eIF4A, and eIF3. eIF4GII, like eIF4GI, is also cleaved upon picornavirus infection. eIF4GII restores cap-dependent translation in a reticulocyte lysate which had been pretreated with rhinovirus 2A to cleave endogenous eIF4G. Finally, eIF4GII exists as a complex with eIF4E in HeLa cells, because eIF4GII and eIF4E can be purified together by cap affinity chromatography. Taken together, our findings indicate that eIF4GII is a functional homolog of eIF4GI. These results may have important implications for the understanding of the mechanism of shutoff of host protein synthesis following picornavirus infection.     

Stat3 links activated keratinocytes and immunocytes required for development of psoriasis in a novel transgenic mouse model

Here we report that epidermal keratinocytes in psoriatic lesions are characterized by activated Stat3. Transgenic mice with keratinocytes expressing a constitutively active Stat3 (K5.Stat3C mice) develop a skin phenotype either spontaneously, or in response to wounding, that closely resembles psoriasis. Keratinocytes from K5.Stat3C mice show upregulation of several molecules linked to the pathogenesis of psoriasis. In addition, the development of psoriatic lesions in K5.Stat3C mice requires cooperation between Stat3 activation in keratinocytes and activated T cells. Finally, abrogation of Stat3 function by a decoy oligonucleotide inhibits the onset and reverses established psoriatic lesions in K5.Stat3C mice. Thus, targeting Stat3 may be potentially therapeutic in the treatment of psoriasis.     

A synthesis of the phenolic lipid, 3-[(Z)-pentadec-8-enyl] catechol, (15:1)-urushiol

A synthesis of (15:1)-urushiol, urushiol monoene, 3-[(Z)-pentadec-8-enyl] catechol, 1,2-dihydroxy-3-[(Z)-pentadec-8-enyl] benzene, one of the toxic principles of Rhus toxicodendron and of Rhus vernicifera is described. 6-Chlorohexan-1-ol protected at the OH group with ethyl vinyl ether reacted with 2,3-dimethoxybenzaldehyde in the presence of lithium to give, after removal of the protective group with methanolic 4-toluenesulphonic acid, 1-(2,3-dimethoxyphenyl) heptane-1,7-diol. Catalytic hydrogenolysis in ethanol with palladium–carbon selectively afforded 7-(2,3-dimethoxyphenyl)heptane-1-ol accompanied by a small proportion of the 7-(3-methoxyphenyl)heptane-1-diol, formed by demethoxylation. Reaction of the dimethoxy compound with boron tribromide resulted in both bromination and demethylation to give 7-(2,3-dihydroxyphenyl) heptylbromide. This bromide in tetrahydrofuran (THF) containing hexamethylphosphoric triamide reacted with excess lithium oct-1-yne to give 3-(pentadec-8-enyl)catechol which, by catalytic hydrogenation in ethyl acetate containing quinoline, selectively formed the required cis product, 3-[(Z)-pentadec-8-enyl]catechol which was identical chromatographically and spectroscopically with urushiol monoene separated from the natural product.     

Recent Advances in GFP Folding Reporter and Split-GFP Solubility Reporter Technologies. Application to Improving the Folding and Solubility of Recalcitrant Proteins from Mycobacterium tuberculosis

We have improved our green fluorescent protein (GFP) folding reporter technology [Waldo et al., (1999) Nat. Biotechnol. 17, 691–695] to evolve recalcitrant proteins from Mycobacterium tuberculosis. The target protein is inserted into the scaffolding of the GFP, eliminating false-positive artifacts caused by expression of truncated protein variants from internal cryptic ribosome binding sites in the target RNA. In parallel, we have developed a new quantitative fluorescent protein tagging and detection system based on micro-domains of GFP. This split-GFP system, which works both in vivo and in vitro, is amenable to high-throughput assays of protein expression and solubility [Cabantous et al., (2005) Nat. Biotechnol. 23, 102–107]. Together, the GFP folding reporter and split-GFP technologies offer a comprehensive system for manipulating and improving protein folding and solubility.     

The Induction of Phagocytic Activation by Mixtures of the Water Chlorination By‐Products,Dichloroacetate‐ and Trichloroacetate,in Mice after Subchronic Exposure

In this study, groups of B6C3F1 male mice were treated with dichloroacetate (DCA), trichloroacetate (TCA), and mixtures of the compounds (Mix I, II, and III) daily by gavage, for 13 weeks. The tested doses were 7.5, 15, and 30 mg DCA/kg/day and 12.5, 25, and 50 mg TCA/kg/day. The DCA: TCA ratios in Mix I, II, and III were 7.5:12.5, 15:25, and 30:50 mg/kg/day, respectively. Peritoneal lavage cells were collected at the end of the treatment period and assayed for the biomarkers of phagocytic activation, including superoxide anion and tumor necrosis factor‐alpha production, and myeloperoxidase activity. The mixtures produced nonlinear effects on the biomarkers of phagocytic activation, with Mix I and II effects were found to be additive, but Mix III effects were found to be less than additive. © 2013 Wiley Periodicals, Inc. J BiochemMol Toxicol 27:237‐242, 2013; View this article online at wileyonlinelibrary.com . DOI 10.1002/jbt.21476