Why do people visit primate tourism sites? Investigating macaque tourism in Japan and Indonesia

Primates - Primates are popular species in wildlife tourism contexts and provide economic benefits to habitat countries where primate-based tourism activities are a part of the country’s...     

Estimation of endogenous indole-3-acetic acid in leaf explants and a protocol for direct regeneration in Lilium cv. Pavia

In Vitro Cellular & Developmental Biology - Plant - A method for regeneration via direct organogenesis in Lilium cv. Pavia using leaf primary explants has been established. Outer leaves from in...     

Development of a novel solid-state fermentation strategy for the production of poly-3-hydroxybutyrate using polyurethane foams by Bacillus sphaericus NII 0838

The extensive use of synthetic plastics has caused serious waste disposal problems in our environment. Poly-3-hydroxybutyrates (PHB) are eco-friendly bacterial polyesters which are produced under unbalanced nutrient conditions. Few reports are available on PHB production by solid state fermentation (SSF). We have developed a novel SSF bioprocess in which polyurethane foam (PUF) is used as a physical inert support for the production of PHB by Bacillus sphaericus NII 0838. Media engineering for optimal PHB production was carried out using response surface methodology (RSM) adopting a Box–Behnken design. The factors optimized by RSM were inoculum size, pH and (NH₄)₂SO₄ concentration. Under optimized conditions—6.5 % inoculum size, 1.7 % (w/v) (NH₄)₂SO₄ and pH 9.0—PHB production and biomass were 0.169?±?0.03 and 0.4?±?0.002 g/g PUF, respectively. This is the first report on PHB production by SSF using PUF as an inert support. Our results demonstrate that SSF can be used as an alternative strategy for the production of PHB.     

Peregrination of the selectivity filter delineates the pore of the human voltage-gated proton channel hHV1

Extraordinary selectivity is crucial to all proton-conducting molecules, including the human voltage-gated proton channel (hH_V1), because the proton concentration is >10⁶ times lower than that of other cations. Here we use “selectivity filter scanning” to elucidate the molecular requirements for proton-specific conduction in hH_V1. Asp¹¹², in the middle of the S1 transmembrane helix, is an essential part of the selectivity filter in wild-type (WT) channels. After neutralizing Asp¹¹² by mutating it to Ala (D112A), we introduced Asp at each position along S1 from 108 to 118, searching for “second site suppressor” activity. Surprisingly, most mutants lacked even the anion conduction exhibited by D112A. Proton-specific conduction was restored only with Asp or Glu at position 116. The D112V/V116D channel strikingly resembled WT in selectivity, kinetics, and ΔpH-dependent gating. The S4 segment of this mutant has similar accessibility to WT in open channels, because R211H/D112V/V116D was inhibited by internally applied Zn²⁺. Asp at position 109 allowed anion permeation in combination with D112A but did not rescue function in the nonconducting D112V mutant, indicating that selectivity is established externally to the constriction at F150. The three positions that permitted conduction all line the pore in our homology model, clearly delineating the conduction pathway. Evidently, a carboxyl group must face the pore directly to enable conduction. Molecular dynamics simulations indicate reorganization of hydrogen bond networks in the external vestibule in D112V/V116D. At both positions where it produces proton selectivity, Asp frequently engages in salt linkage with one or more Arg residues from S4. Surprisingly, mean hydration profiles were similar in proton-selective, anion-permeable, and nonconducting constructs. That the selectivity filter functions in a new location helps to define local environmental features required to produce proton-selective conduction.     

Bacopa monnieri and l-Deprenyl Differentially Enhance the Activities of Antioxidant Enzymes and the Expression of Tyrosine Hydroxylase and Nerve Growth Factor via ERK 1/2 and NF-κB Pathways in the Spleen of Female Wistar Rats

Aging is characterized by development of diseases and cancer due to loss of central and peripheral neuroendocrine-immune responses. Free radicals exert deleterious effects on neural-immune functions in the brain, heart, and lymphoid organs and thus, affecting the health. Bacopa monnieri (brahmi), an Ayurvedic herb, and l-deprenyl, a monoamine oxidase-B inhibitor, have been widely used in the treatment of neurodegenerative diseases. The purpose of this study was to investigate whether brahmi (10 and 40 mg/kg BW) and deprenyl (1 and 2.5 mg/kg BW) treatment of 3-month old female Wistar rats for 10 days can modulate the activities of antioxidant enzymes [superoxide dismutase (SOD), catalase (CAT), and glutathione peroxidase (GPx)] in the brain and spleen. In addition, the effects of these compounds on the expression of tyrosine hydroxylase (TH), nerve growth factor (NGF), the intracellular signaling markers, p-ERK1/2, p-CREB, and p-NF-kB, and nitric oxide (NO) production were measured in the spleen by Western blot analysis. Both brahmi and deprenyl enhanced CAT activity, and p-TH, NGF, and p-NF-kB expression in the spleen. However, deprenyl alone was found to enhance the p-ERK1/2 and p-CREB expression in the spleen. The activities of SOD, CAT, and GPx in the thymus, mesenteric lymph nodes, heart, and brain areas (frontal cortex, medial basal hypothalamus, striatum, and hippocampus) were differentially altered by brahmi and deprenyl. Brahmi alone enhanced NO production in the spleen. Taken together, these results suggest that both brahmi and deprenyl can protect the central and peripheral neuronal systems through their unique effects on the antioxidant enzyme activities and intracellular signaling pathways.     

Neural precursor cell-expressed developmentally down-regulated protein 4-2 (Nedd4-2) regulation by 14-3-3 protein binding at canonical serum and glucocorticoid kinase 1 (SGK1) phosphorylation sites

Regulation of epithelial Na(+) channel (ENaC)-mediated transport in the distal nephron is a critical determinant of blood pressure in humans. Aldosterone via serum and glucocorticoid kinase 1 (SGK1) stimulates ENaC by phosphorylation of the E3 ubiquitin ligase Nedd4-2, which induces interaction with 14-3-3 proteins. However, the mechanisms of SGK1- and 14-3-3-mediated regulation of Nedd4-2 are unclear. There are three canonical SGK1 target sites on Nedd4-2 that overlap phosphorylation-dependent 14-3-3 interaction motifs. Two of these are termed "minor," and one is termed "major," based on weak or strong binding to 14-3-3 proteins, respectively. By mass spectrometry, we found that aldosterone significantly stimulates phosphorylation of a minor, relative to the major, 14-3-3 binding site on Nedd4-2. Phosphorylation-deficient minor site Nedd4-2 mutants bound less 14-3-3 than did wild-type (WT) Nedd4-2, and minor site Nedd4-2 mutations were sufficient to inhibit SGK1 stimulation of ENaC cell surface expression. As measured by pulse-chase and cycloheximide chase assays, a major binding site Nedd4-2 mutant had a shorter cellular half-life than WT Nedd4-2, but this property was not dependent on binding to 14-3-3. Additionally, a dimerization-deficient 14-3-3ε mutant failed to bind Nedd4-2. We conclude that whereas phosphorylation at the Nedd4-2 major site is important for interaction with 14-3-3 dimers, minor site phosphorylation by SGK1 may be the relevant molecular switch that stabilizes Nedd4-2 interaction with 14-3-3 and thus promotes ENaC cell surface expression. We also propose that major site phosphorylation promotes cellular Nedd4-2 protein stability, which potentially represents a novel form of regulation for turnover of E3 ubiquitin ligases.     

A conserved isoleucine in the LOV1 domain of a novel phototropin from the marine alga Ostreococcus tauri modulates the dark state recovery of the domain

Background

Phototropins are UV-A/blue light receptor proteins with two LOV (Light-Oxygen-Voltage) sensor domains at their N terminus and a kinase domain at the C-terminus in photoautotrophic organisms. This is the first research report of a canonical phototropin from marine algae Ostreococcus tauri.

Methods

We synthesized core LOV1 (OtLOV1) domain-encoding portion of the phototropin gene of O. tauri, the domain was heterologously expressed, purified and assessed for its spectral properties and dark recovery kinetics by UV–Visible, fluorescence spectroscopy and mutational studies. Quaternary structure characteristics were studied by SEC and glutaraldehyde crosslinking.

Results

The absorption spectrum of OtLOV1 lacks the characteristic 361 nm peak shown by other LOV1 domains. It undergoes a photocycle with a dark state recovery time of approximately 30 min (τ = 300.35 s). Native OtLOV1 stayed as dimer in aqueous solution and the dimer formation was light and concentration independent. Mutating isoleucine at 43rd position to valine accelerated the dark recovery time by more than 10-fold. Mutating it to serine reduced sensitivity to blue light, but the dark recovery time remained unaltered. I43S mutation also destabilized the FMN binding to a great extent.

Conclusion

The OtLOV1 domain of the newly identified OtPhot is functional and the isoleucine at position 43 of OtLOV1 is the key residue responsible for fine-tuning the domain properties.

General significance

This is the first characterized LOV1 domain of a canonical phototropin from a marine alga and spectral properties of the domain are similar to that of the LOV1 domain of higher plants.     

Unique and analogous functions of aquaporin 0 for fiber cell architecture and ocular lens transparency

Aquaporin (AQP) 1 and AQP0 water channels are expressed in lens epithelial and fiber cells, respectively, facilitating fluid circulation for nourishing the avascular lens to maintain transparency. Even though AQP0 water permeability is 40-fold less than AQP1, AQP0 is selectively expressed in the fibers. Delimited AQP0 fiber expression is attributed to a unique structural role as an adhesion protein. To validate this notion, we determined if wild type (WT) lens ultrastructure and fiber cell adhesion are different in AQP0^−/−, and TgAQP1^+/+/AQP0^−/− mice that transgenically express AQP1 (TgAQP1) in fiber cells without AQP0 (AQP0^−/−). In WT, lenses were transparent with ‘Y’ sutures. Fibers contained opposite end curvature, lateral interdigitations, hexagonal shape, and were arranged as concentric growth shells. AQP0^−/− lenses were cataractous, lacked ‘Y’ sutures, ordered packing and well-defined lateral interdigitations. TgAQP1^+/+/AQP0^−/− lenses showed improvement in transparency and lateral interdigitations in the outer cortex while inner cortex and nuclear fibers were severely disintegrated. Transmission electron micrographs exhibited tightly packed fiber cells in WT whereas AQP0^−/− and TgAQP1^+/+/AQP0^−/− lenses had wide extracellular spaces. Fibers were easily separable by teasing in AQP0^−/− and TgAQP1^+/+/AQP0^−/− lenses compared to WT. Our data suggest that the increased water permeability through AQP1 does not compensate for loss of AQP0 expression in TgAQP1^+/+/AQP0^−/− mice. Fiber cell AQP0 expression is required to maintain their organization, which is a requisite for lens transparency. AQP0 appears necessary for cell-to-cell adhesion and thereby to minimize light scattering since in the AQP0^−/− and TgAQP1^+/+/AQP0^−/− lenses, fiber cell disorganization was evident.