| 1. |
- Lindh, Ingrid, et al.
(författare)
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Production of the p24 capsid protein from HIV-1 subtype C in Arabidopsis thaliana and Daucus carota using an endoplasmic reticulum-directing SEKDEL sequence in protein expression constructs
- 2009
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Ingår i: Protein Expression and Purification. - St. Louis : Academic Press. - 1046-5928 .- 1096-0279. ; 66:1, s. 46-51
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Tidskriftsartikel (refereegranskat)abstract
- An optimized gene expression construct was designed in order to increase the accumulation of the HIV-1 subtype C p24 protein in Arabidopsis thaliana and carrot (Daucus carota) plants. An ER retention signal was introduced into the genetic construct generating a p24 protein containing a SEKDEL amino acid sequence at its C-terminus. Mature A. thaliana plants and carrot cells were transformed using Agrobacterium tumefaciens carrying the improved pGreen0229/p24_SEKDEL vector. Several transgenic plant lines were obtained from both plant species by growth on selective medium and confirmed by PCR. Transformed lines were analyzed for p24 protein content by western blotting using anti-p24-specific antibodies and by Southern blotting to establish the number of copies of the insert in the plant nuclear genome. To estimate the accumulation levels of p24 protein in the plants, ELISA was run using soluble plant extracts. By comparing these results with our previous findings, the ER retention signal increased the level of p24 protein 5-fold in the Arabidopsis thaliana plants. In carrot taproot, the content of p24_SEKDEL protein was approximately half of that in Arabidopsis on a fresh weight basis and was stable in planta for several months. However, on a total soluble protein basis, carrots produced considerable higher levels of the p24_SEKDEL protein than Arabidopsis.
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| 2. |
- Saénz-de la O, Diana, et al.
(författare)
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Antioxidant and drought‑acclimation responses in UV‑B‑exposed transgenic Nicotiana tabacum displaying constitutive overproduction of H2O2
- 2023
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Ingår i: Photochemical and Photobiological Sciences. - : Springer. - 1474-905X .- 1474-9092. ; 22:10, s. 2373-2387
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Tidskriftsartikel (refereegranskat)abstract
- Hydrogen peroxide (H2O2) is an important molecule that regulates antioxidant responses that are crucial for plant stress resistance. Exposure to low levels of ultraviolet-B radiation (UV-B, 280–315 nm) can also activate antioxidant defenses and acclimation responses. However, how H2O2 and UV-B interact to promote stress acclimation remains poorly understood. In this work, a transgenic model of Nicotiana tabacum cv Xanthi nc, with elevated Mn-superoxide dismutase (Mn-SOD)activity, was used to study the interaction between the constitutive overproduction of H2O2 and a 14-day UV-B treatment (1.75 kJ m−2 d−1 biologically effective UV-B). Subsequently, these plants were subjected to a 7-day moderate drought treatment to evaluate the impact on drought resistance of H2O2- and UV-dependent stimulation of the plants' antioxidant system. The UV-B treatment enhanced H2O2 levels and altered the antioxidant status by increasing the epidermal flavonol index, Trolox Equivalent Antioxidant Capacity, and catalase, peroxidase and phenylalanine ammonia lyase activities in the leaves. UV-B also retarded growth and suppressed acclimation responses in highly H2O2-overproducing transgenic plants. Plants not exposed to UV-B had a higher drought resistance in the form of higher relative water content of leaves. Our data associate the interaction between Mn-SOD transgene overexpression and the UV-B treatment with a stress response. Finally, we propose a hormetic biphasic drought resistance response curve as a function of leaf H2O2 content in N. tabacum cv Xanthi.
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| 3. |
- Grahn, Elin M., 1970-, et al.
(författare)
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Structural Characterization of a Lectin from the Mushroom Marasmius oreades in Complex with the Blood Group B Trisaccharide and Calcium
- 2009
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Ingår i: Journal of Molecular Biology. - Amsterdam : Academic Press. - 0022-2836 .- 1089-8638. ; 390:3, s. 457-466
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Tidskriftsartikel (refereegranskat)abstract
- MOA (Marasmius oreades agglutinin), a lectin isolated from fruiting bodies of the mushroom M. oreades, specifically binds nonreducing terminal Galα(1,3)Gal carbohydrates, such as that which occurs in the xenotransplantation epitope Galα(1,3)Galβ(1,4)GlcNAc and the branched blood group B determinant Galα(1,3)[Fucα(1,2)]Gal. Here, we present the crystal structure of MOA in complex with the blood group B trisaccharide solved at 1.8 Å resolution. To our knowledge, this is the first blood-group-B-specific structure reported in complex with a blood group B determinant. The carbohydrate ligand binds to all three binding sites of the N-terminal β-trefoil domain. Also, in this work, Ca2+ was included in the crystals, and binding of Ca2+ to the MOA homodimer altered the conformation of the C-terminal domain by opening up the cleft containing a putative catalytic site.
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| 4. |
- Saenz Mendez, Patricia, et al.
(författare)
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Homology models of human all-trans retinoic acid metabolizing enzymes CYP26B1 and CYP26B1 spliced-variant.
- 2012
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Ingår i: Journal of Chemical Information and Modeling. - Washington, USA : American Chemical Society (ACS). - 1549-9596 .- 1549-960X. ; 52:10, s. 2631-2637
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Tidskriftsartikel (refereegranskat)abstract
- Homology models of CYP26B1 (cytochrome P450RAI2) and CYP26B1 spliced variant were derived using the crystal structure of cyanobacterial CYP120A1 as template for the model building. The quality of the homology models generated were carefully evaluated, and the natural substrate all-trans-retinoic acid (atRA), several tetralone-derived retinoic acid metabolizing blocking agents (RAMBAs), and a well-known potent inhibitor of CYP26B1 (R115866) were docked into the homology model of full-length cytochrome P450 26B1. The results show that in the model of the full-length CYP26B1, the protein is capable of distinguishing between the natural substrate (atRA), R115866, and the tetralone derivatives. The spliced variant of CYP26B1 model displays a reduced affinity for atRA compared to the full-length enzyme, in accordance with recently described experimental information.
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| 5. |
- Eriksson, Leif A., 1964-, et al.
(författare)
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Tetrazole derivatives as cytochrome p450 inhibitors
- 2019
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Patent (populärvet., debatt m.m.)abstract
- According to the invention there is provided a compound of formula I, wherein R1 and R2 have meanings given in the description, which compounds are useful in the treatment of skin disorders and other diseases.
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| 6. |
- Kännaste, Astrid, et al.
(författare)
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Odors of Norway spruce (Picea abies L.) seedlings : differences due to age and chemotype
- 2013
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Ingår i: Trees. - : Springer. - 0931-1890 .- 1432-2285. ; 27, s. 149-159
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Tidskriftsartikel (refereegranskat)abstract
- Small conifer seedlings (mini-seedlings) are less damaged by the large pine weevil Hylobius abietis (L.) (Coleoptera: Curculionidae) compared to conventional seedlings. Chemical difference between the seedling types is one possible explanation for this phenomenon. In the present paper, the emissions of volatile organic compounds (VOC) of 7- to 43-week-old Norway spruce [Picea abies (L.) Karst.] seedlings were analyzed. Collection and identification of the volatiles was made by solid phase micro-extraction and gas chromatography mass spectrometry (SPME–GC–MS). The enantiomers of α-pinene and limonene were separated in a two-dimensional GC (2D-GC). Most of the seedlings represented either a limonene- or a bornyl acetate-chemotype. Only minor changes in the volatile composition of the two types of seedlings were found during the first year. Age-related changes, however, were found in the volatiles released by wounded phloem where green leaf volatiles (GLVs) and borneol were the dominated VOC for young seedling. The attractive compound for the pine weevil, α-pinene, was first detected in the phloem emissions of 18- to 22-week-old seedlings. Different storage conditions of the seedlings during the winter/early spring-phase influenced the volatile composition in the phloem. High amount of GLVs was characteristic for the 43-week-old seedlings stored in naturally changing outdoor temperature, but not present in the seedlings winter-stored at a constant temperature of −4 °C. The possible role of these observed differences in odor emissions between seedlings of different age and physiological status for the feeding preferences of the large pine weevil is discussed.
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| 7. |
- Kalbina, Irina, et al.
(författare)
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Two separate UV-B radiation wavelength regions control expression of different molecular markers in Arabidopsis thaliana
- 2008
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Ingår i: Functional Plant Biology. - Collinwood VIC : CSIRO. - 1445-4408 .- 1445-4416. ; 35:3, s. 222-227
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Tidskriftsartikel (refereegranskat)abstract
- Fluence-response curves were obtained at nine wavelengths in the interval 280-360 nm for mRNA transcripts of four molecular markers induced by ultraviolet-B (UV-B) radiation in Arabidopsis thaliana: CHS (encoding chalcone synthase), PDX1.3 (encoding an enzyme involved in formation of pyridoxine), MEB5.2 (encoding a protein with unknown function but which is strongly up-regulated by UV-B), and LHCB1*3 (encoding a chlorophyll a/b binding protein). Intact Arabidopsis plants were irradiated for 3h using a high intensity deuterium radiation source and narrow bandwith filters (Kalbin et al. 2005, J. Biochem. Biophys. Meth. 65, 1-12) without supplementary PAR. The results obtained suggest the existence of two distinct UV-B signal responses: one sensitive between 300 and 310 nm and the other sensitive around 280-290 nm. Among the investigated molecular markers, CHS and PDX1.3 were regulated through the chromophore absorbing around 300 nm, whereas MEB5.2 and LHCB1*3 were regulated through the chromophore absorbing at 280-290 nm. The results obtained show that at least two signal transduction pathways exist that regulate gene expression as a result of absorption of UV-B radiation in plants.
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| 8. |
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| 9. |
- Ostrakhovitch, Elena A, et al.
(författare)
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P53 mediated regulation of metallothionein transcription in breast cancer cells
- 2007
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Ingår i: Journal of Cellular Biochemistry. - Hoboken : Wiley-Liss. - 0730-2312 .- 1097-4644. ; 102:6, s. 1571-1583
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Tidskriftsartikel (refereegranskat)abstract
- Recent studies have shown that only breast cancer epithelial cells with intact p53 can induce metallothionein (MT) synthesis after exposure to metals. In this study, the potential role of p53 on regulation of MT was investigated. Results demonstrate that zinc and copper increased metal response elements (MREs) activity and MTF-1 expression in p53 positive MN1 and parental MCF7 cells. However, inactivation of p53 by treatment with pifithrin- or the presence of inactive p53 inhibited MRE-dependent reporter gene expression in response to metals. MTF-1 levels remained unchanged after treatment with zinc in cells with nonfunctional p53. The introduction of wild-type p53 in MDD2 cells, containing nonfunctional p53, enhanced the ability of zinc to increase MRE-dependent reporter gene expression. The cellular level of p21Cip1/WAF1 was increased in MDD2 cells after p53 transfection, confirming the presence of active p53. The treatment of MN1 and parental MCF7 with trichostatin A led to a sixfold increase in the MRE activity in response to zinc. On the contrary, MRE activity remained unaltered in MDD2 cells with inactive p53. The above results demonstrate that activation of p53 is an important factor in metal regulation of MT. J. Cell. Biochem. 102: 1571-1583, 2007.
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| 10. |
- Mohlin, Camilla, 1972-, et al.
(författare)
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Evaluation of Congo Red Staining in Degenerating Porcine Photoreceptors In Vitro : Protective Effects by Structural and Trophic Support
- 2018
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Ingår i: Journal of Histochemistry and Cytochemistry. - : Sage Publications. - 0022-1554 .- 1551-5044. ; 66:9
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Tidskriftsartikel (refereegranskat)abstract
- Congo red (CR) is a histological stain used for the detection of extracellular amyloids mediating various neurodegenerative diseases. Given that damaged photoreceptors appear to degenerate similarly to other nerve cells, CR staining was evaluated in experimentally injured porcine retina. CR staining appeared mostly as discrete cytosolic deposits with no obvious plaque formation during the investigated time period. Increases of CR labeling coincided temporally with the known accumulation of mislocalized opsins and increases of cell death. Coculture, either with human retinal pigment epithelium (ARPE) or human neural progenitor (ReN) cells, was accompanied by a significant reduction of CR labeling. Of particular interest was the reduction of CR labeling in cone photoreceptors, which are important for the perception of color and fine details and afflicted in age-related macular degeneration (AMD). Electron microscopy revealed inclusions in the inner segment, cell body, and occasionally synaptic terminals of photoreceptor cells in cultured specimens. Closer examinations indicated the presence of different types of inclusions resembling protein aggregates as well as inclusion bodies. The current results indicate that injury-related response resulted in accumulation of CR deposits in photoreceptor cells, and that trophic and/or structural support attenuated this response.
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