Daniele Silvestro

University of Gävle · Department of Building, Energy and Environmental Engineering

Some plant species are known to cause calcium intoxification in grazing animals. This has been attributed to the presence of vitamin D3-like activity. However, research into the presence of vitamin D3 in plants has been limited. One reason for this may be limitations in the analytical methods available for unambiguous detection and quantification o...

Sterols are crucial lipid components that regulate membrane permeability and fluidity and are the precursors of bioactive steroids. The plant sterols exist as three major forms, free sterols, steryl glycosides and steryl esters. The storage of steryl esters in lipid droplets has been shown to contribute to cellular sterol homeostasis. To further do...

Cyanogenic glycosides are phytoanticipins involved in plant defence against herbivores by virtue of their ability to release toxic hydrogen cyanide (HCN) upon tissue disruption. In addition, endogenous turnover of cyanogenic glycosides without the liberation of HCN may offer plants an important source of reduced nitrogen at specific developmental s...

Vitamin D3 is a secosterol hormone critical for bone growth and calcium homeostasis, produced in vertebrate skin by photolytic conversion of the cholesterol biosynthetic intermediate provitamin D3. Insufficient levels of vitamin D3 especially in the case of low solar UV-B irradiation is often compensated by an intake of a dietary source of vitamin...

Metabolite channeling by a dynamic metabolon The specialized metabolite dhurrin breaks down into cyanide when plant cell walls have been chewed, deterring insect pests. Laursen et al. found that the enzymes that synthesize dhurrin in sorghum assemble as a metabolon in lipid membranes (see the Perspective by Dsatmaichi and Facchini). The dynamic nat...

The pleiotropic drug resistance (PDR) transporter Pdr11p is expressed under anaerobic growth conditions at the plasma membrane of the yeast Saccharomyces cerevisiae, where it facilitates the uptake of exogenous sterols. Members of the fungal PDR family contain six conserved cysteines in their extracellular loops (ECL). For the functional analysis o...

P5A ATPases are expressed in the endoplasmic reticulum (ER) of all eukaryotic cells, and their disruption results in severe ER stress. However, the function of these ubiquitous membrane proteins, which belong to the P-type ATPase superfamily, is unknown. We purified a functional tagged version of the Saccharomyces cerevisiae P5A ATPase Spf1p and ob...

Sterol uptake in fungi is a multistep process that involves interaction between external sterols and the cell wall, incorporation of sterol molecules into the plasma membrane, and subsequent integration into intracellular membranes for turnover. ATP-binding cassette (ABC) transporters have been implicated in sterol uptake, but key features of their...

Changes in vitamin D(3) and its metabolites were investigated following UVB- and heat-treatment in the leaves of Solanum glaucophyllum Desf., Solanum lycopersicum L. and Capsicum annuum L. The analytical method used was a sensitive and selective liquid chromatography electrospray ionisation tandem mass spectrometry (LC-ESI-MS/MS) method including D...

Primers used for cloning of the YFP-fused constructs into inducible yeast expression vectors. The YFP reverse primer is common for all the constructs being generated on the YFP 3′ sequence. (DOC)

Primers used to assembly the YFP fused constructs. (DOC)

Western blot analysis of wild type Arabidopsis and dwarf5-2, ste1-1 and dim mutant plants expressing the corresponding YFP-fused proteins. The figure shows the accumulation of DWARF5-YFP (∼79 KDa) and DIM-YFP (∼92 KDa). STE1-YFP was not detected probably due to the relative low abundance in the analysed tissues. Protein extracts were prepared by ho...

Sterol profile and composition of an Arabidopsis wild type plant. Sterol peaks identified by their retention time and confirmed by GC-MS (prominent mass fragments not shown here) are: 1, cholesterol; 3, Δ7-cholesterol; 4, campesterol; 10, sitosterol; 11, isofucosterol; 14, stigmasterol; 16, brassicasterol. In bold the more abundant sterol. (TIF)

Subcellular localization of STE1-YFP in Arabidopsis ste1-1::STE1-YFP plants. The movie is showing the subcellular trafficking of LPs observed while collecting the YFP signal. (MOV)

Subcellular localization of DIM-YFP and STE1-YFP proteins in Arabidopsis. Confocal images of leaves showing localization of (A) DIM-YFP and (D) STE1-YFP in the cell. (B, E) Chlorophyll autofluorescence. (C, F) Overlay images of YFP and autofluorescence channels. Scale bars = 25 µm. (TIF)

In silico prediction of subcellular localization (Predotar) and signal peptide presence (SignalP) for DWARF5, STE1 and DIM based on their amino acid sequences. (DOC)

The Italian cigar manufacturing process includes a fermentation step that leads to accumulation of nitrite and tobacco-specific nitrosamines (TSNA), undesirable by-products due to their negative impact on health. In this study, growth and biochemical properties of Debaryomyces hansenii TOB-Y7, a yeast strain that predominates during the early phase...

a–b In silico analysis of the deduced amino acid sequence of D. hansenii TOB-Y7 YNI1. a The functional domains of D. hansenii TOB-Y7 NiR were identified by the NCBI Conserved Domain Database program available at the site http:// www. ncbi. nlm. nih. gov/ Structure/ cdd/ cdd. shtml. Fer... Bacterioferritin-associated ferredoxin-like [2Fe-2S] binding...

The Italian Toscano cigar production includes a fermentation step that starts when dark fire-cured tobacco leaves are moistened and mixed with ca. 20% prefermented tobacco to form a 500-kg bulk. The dynamics of the process, lasting ca. 18 days, has never been investigated in detail, and limited information is available on microbiota involved. Here...