Hox clusters as models for vertebrate genome evolution

The surprising variation in the number of Hox clusters and the genomic architecture within vertebrate lineages, especially within the ray-finned fish, reflects a history of duplications and subsequent lineage-specific gene loss. Recent research on the evolution of conserved non-coding sequences (CNS) in Hox clusters promises to reveal interesting results for functional and phenotypic diversification.     

Interactions between humic matter and bacteria when disinfecting water with UV light

Aims:  To investigate the impact of aquatic humic matter on the inactivation of Escherichia coli and Bacillus subtilis by ultraviolet (UV) light.
Methods and Results:  A bench-scale study investigated the potential for Aldrich^® humic acid (AHA) and Suwannee River natural organic matter (SR-NOM) to coat the surface of E. coli and B. subtilis and offer protection from low-pressure UV light. UV doses of 5 and 14 mJ cm⁻² were applied using a collimated beam at four concentrations of humic matter (0, 10, 50 and 120 mg l⁻¹) in reagent grade water. Both AHA and SR-NOM were found to offer statistically significant protection of both E. coli and B. subtilis at concentrations of 50 and 120 mg l⁻¹ for a UV dose of 14 mJ cm⁻².
Conclusions:  Both E. coli and B. subtilis are susceptible to coating by humic matter which can reduce the sensitivity of the cells to UV light.
Significance and impact of the study:  Micro-organisms in the environment may acquire characteristics through interaction with humic matter that render them more resistant to UV disinfection than would be predicted based on laboratory inactivation studies using clean cells.     

Phosphorus effects on metabolic processes in monoxenic arbuscular mycorrhiza cultures

The influence of external phosphorus (P) on carbon (C) allocation and metabolism as well as processes related to P metabolism was studied in monoxenic arbuscular mycorrhiza cultures of carrot (Daucus carota). Fungal hyphae of Glomus intraradices proliferated from the solid minimal medium containing the colonized roots into C-free liquid minimal medium with different P treatments. The fungus formed around three times higher biomass in P-free liquid medium than in medium with 2.5 mM inorganic P (high-P). Mycelium in the second experiment was harvested at an earlier growth stage to study metabolic processes when the mycelium was actively growing. P treatment influenced the root P content and [(13)C]glucose administered to the roots 7 d before harvest gave a negative correlation between root P content and (13)C enrichment in arbuscular mycorrhiza fungal storage lipids in the extraradical hyphae. Eighteen percent of the enriched (13)C in extraradical hyphae was recovered in the fatty acid 16:1omega5 from neutral lipids. Polyphosphate accumulated in hyphae even in P-free medium. No influence of P treatment on fungal acid phosphatase activity was observed, whereas the proportion of alkaline-phosphatase-active hyphae was highest in high-P medium. We demonstrated the presence of a motile tubular vacuolar system in G. intraradices. This system was rarely seen in hyphae subjected to the highest P treatment. We concluded that the direct responses of the extraradical hyphae to the P concentration in the medium are limited. The effects found in hyphae seemed instead to be related to increased availability of P to the host root.     

Engineering disulfide bonds of the novel human beta-defensins hBD-27 and hBD-28: differences in disulfide formation and biological activity among human beta-defensins

Human beta-defensins comprise a large number of peptides that play a functional role in the innate and adaptive immune system. Recently, clusters of new beta-defensin genes with predominant expression in testicular tissue have been discovered on different chromosomes by bioinformatics. beta-Defensins share a common pattern of three disulfides that are essential for their biological effects. Here we report for the first time the chemical synthesis of the new fully disulfide-bonded beta-defensins hBD-27 and hBD-28, and compare the results with synthetic procedures to obtain the known hBD-2 and hBD-3. While hBD-27 was readily converted into a product with the desired disulfide pattern by oxidative folding, hBD-28 required a selective protective group strategy to introduce the three disulfide bonds. The established synthetic processes were applied to the synthesis of hBD-2, which, like hBD-27, was accessible by oxidative folding, whereas hBD-3 required a selective strategy comparable to hBD-28. Experimental work demonstrated that trityl, acetamidomethyl, and t-butyl are superior to other protection strategies. However, the suitable pairwise arrangement of the protective groups can be different, as shown here for hBD-3 and hBD-28. Determination of the minimum inhibitory concentration against different bacteria revealed that hBD-27, in contrast to other beta-defensins tested, has virtually no antimicrobial activity. Compared to the other peptides tested, hBD-27 showed almost no cytotoxic activity, measured by hemoglobin release of erythrocytes. This might be due to the low positive net charge, which is significantly higher for hBD-2, hBD-3, and hBD-28.     

New Approaches for Absolute Quantification of Stable‐Isotope‐Labeled Peptide Standards for Targeted Proteomics Based on a UV Active Tag

Targeted proteomics depends on the availability of stable isotope labeled (SIL) peptide standards, which for absolute protein quantification need to be absolutely quantified. In the present study, three new approaches for absolute quantification of SIL peptides are developed. All approaches rely on a quantification tag (Qtag) with a specific UV absorption. The Qtag is attached to the peptide during synthesis and is removed by tryptic digestion under standard proteomics workflow conditions. While one quantification method (method A) is designed to allow the fast and economic production of absolutely quantified SIL peptides, two other methods (methods B and C) are developed to enable the straightforward re‐quantification of SIL peptides after reconstitution to control and monitor known problems related to peptide solubility, precipitation, and adhesion to vials. All methods yield consistent results when compared to each other and when compared to quantification by amino acid analysis. The precise quantitation methods are used to characterize the in vivo specificity of the H3 specific histone methyltransferase EZH2.     

Barley leaf unrolling. The proline connection

Unrolling of 1 cm sections, taken between 3 and 4 cm from the apex, of 6-day-old, etiolated barley leaves, was promoted by blue (426 nm) and red (658 nm) light. Accompanying such unrolling was a reduction in the level of the free proline of the tissue. When leaf unrolling was prevented by irradiation with far-red (728 nm) light, or treatment with abscisic acid (ABA) following red light irradiation, the level of proline remained more or less unchanged, at the level of the untreated, dark controls. The proline analogue, azetidine carboxylic acid (AZC) powerfully inhibited the light induced leaf opening, emphasizing the significance of proline-containing, structural and functional proteins in barley leaf unrolling. The inhibition imposed by AZC is partially reversible by added proline.     

Blockade of IL-36 Receptor Signaling Does Not Prevent from TNF-Induced Arthritis

Introduction

Interleukin (IL)-36α is a newly described member of the IL-1 cytokine family with a known inflammatory and pathogenic function in psoriasis. Recently, we could demonstrate that the receptor (IL-36R), its ligand IL-36α and its antagonist IL-36Ra are expressed in synovial tissue of arthritis patients. Furthermore, IL-36α induces MAP-kinase and NFκB signaling in human synovial fibroblasts with subsequent expression and secretion of pro-inflammatory cytokines.

Methods

To understand the pathomechanism of IL-36 dependent inflammation, we investigated the biological impact of IL-36α signaling in the hTNFtg mouse. Also the impact on osteoclastogenesis by IL-36α was tested in murine and human osteoclast assays.

Results

Diseased mice showed an increased expression of IL-36R and IL-36α in inflamed knee joints compared to wildtype controls. However, preventively treating mice with an IL-36R blocking antibody led to no changes in clinical onset and pattern of disease. Furthermore, blockade of IL-36 signaling did not change histological signs of TNF-induced arthritis. Additionally, no alteration on bone homeostasis was observed in ex vivo murine and human osteoclast differentiation assays.

Conclusion

Thus we conclude that IL-36α does not affect the development of inflammatory arthritis.