| 1. |
- Hägg Samuelsson, Ulrika, 1973, et al.
(författare)
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Physical exercise capacity is associated with coronary and peripheral vascular function in healthy young adults.
- 2005
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Ingår i: American journal of physiology. Heart and circulatory physiology. - : American Physiological Society. - 0363-6135 .- 1522-1539. ; 289:4, s. H1627-34
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Tidskriftsartikel (refereegranskat)abstract
- Short-term exercise training has been shown to improve cardiovascular function, whereas long-term effects of a physically active lifestyle, on coronary artery function in particular, are still not well studied. We explored possible relationships between physical exercise capacity and coronary and peripheral vascular function in healthy young adults. Twenty-nine healthy young male and female volunteers participated in the study. They underwent 1) basic clinical and echocardiographic characterization, 2) coronary flow velocity reserve (CFVR) measurement of the left anterior descending coronary artery (LAD), 3) common carotid artery (CCA) intima-media thickness (IMT) measurement, 4) assessment of CCA stiffness index (SI), 5) forearm flow-mediated vasodilation (FMD), and 6) submaximal exercise test. The calculated weight-adjusted maximal oxygen uptake capacity (Vo(2 max)(c)) was positively correlated to LAD CFVR and inversely correlated to IMT and SI. Also, subjects with high compared with moderate exercise capacity had higher FMD. In addition, subjects with LAD CFVR in the upper median had greater ratios between endothelium-dependent and -independent vasodilation in the forearm and lower SI in CCA. High exercise capacity due to a physically active lifestyle is associated with high coronary and peripheral artery function, indicating an early protective role of physical exercise for cardiovascular health.
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| 2. |
- Linder, Tomas, et al.
(författare)
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A family of putative transcription termination factors shared amongst metazoans and plants.
- 2005
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Ingår i: Current genetics. - : Springer Science and Business Media LLC. - 0172-8083 .- 1432-0983. ; 48:4, s. 265-9
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Tidskriftsartikel (refereegranskat)abstract
- The human mitochondrial transcription termination factor (mTERF) is involved in the regulation of transcription of the mitochondrial genome. Similarity searches and phylogenetic analysis demonstrate that mTERF is a member of large and complex protein family (the MTERF family) shared amongst metazoans and plants. Interestingly, we identify three novel MTERF genes in vertebrates, which all encode proteins with predicted mitochondrial localization. Members of the MTERF family have so far not been detected in fungi, supporting the notion that mitochondrial transcription regulation may have evolved separately in yeast and animal cells.
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| 3. |
- Nikitina, Julia, et al.
(författare)
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Importance of a single disulfide bond for the PsbO protein of photosystem II : protein structure stability and soluble overexpression in Escherichia coli.
- 2008
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Ingår i: Photosynthesis Research. - : Springer Science and Business Media LLC. - 0166-8595 .- 1573-5079. ; 98, s. 391-403
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Tidskriftsartikel (refereegranskat)abstract
- PsbO protein is an important constituent of the water–oxidizing complex, located on the lumenal side of photosystem II. We report here the efficient expression of the spinach PsbO in E. coli where the solubility depends entirely on the formation of the disulfide bond. The PsbO protein purified from a pET32 system that includes thioredoxin fusion is properly folded and functionally active. Urea unfolding experiments imply that the reduction of the single disulfide bridge decreases stability of the protein. Analysis of inter-residue contact density through the PsbO molecule shows that Cys51 is located in a cluster with high contact density. Reduction of the Cys28–Cys51 bond is proposed to perturb the packing interactions in this cluster and destabilize the protein as a whole. Taken together, our results give evidence that PsbO exists in solution as a compact highly ordered structure, provided that the disulfide bridge is not reduced.
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| 4. |
- Rouhier, Nicolas, et al.
(författare)
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Identification of plant glutaredoxin targets
- 2005
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Ingår i: Antioxidants and Redox Signaling. - Larchmont, NY : Mary Ann Liebert. - 1523-0864 .- 1557-7716. ; 7:7-8, s. 919-929
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Tidskriftsartikel (refereegranskat)abstract
- Glutaredoxins (Grxs) are small ubiquitous proteins of the thioredoxin (Trx) family, which catalyze dithiol–disulfide exchange reactions or reduce protein-mixed glutathione disulfides. In plants, several Trx-interacting proteins have been isolated from different compartments, whereas very few Grx-interacting proteins are known. We describe here the determination of Grx target proteins using a mutated poplar Grx, various tissular and subcellular plant extracts, and liquid chromatography coupled to tandem mass spectrometry detection. We have identified 94 putative targets, involved in many processes, including oxidative stress response [peroxiredoxins (Prxs), ascorbate peroxidase, catalase], nitrogen, sulfur, and carbon metabolisms (methionine synthase, alanine aminotransferase, phosphoglycerate kinase), translation (elongation factors E and Tu), or protein folding (heat shock protein 70). Some of these proteins were previously found to interact with Trx or to be glutathiolated in other organisms, but others could be more specific partners of Grx. To substantiate further these data, Grx was shown to support catalysis of the stroma β-type carbonic anhydrase and Prx IIF of Arabidopsis thaliana, but not of poplar 2-Cys Prx. Overall, these data suggest that the interaction could occur randomly either with exposed cysteinyl disulfide bonds formed within or between target proteins or with mixed disulfides between a protein thiol and glutathione.
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| 5. |
- Shutova, Tatiana, 1964-, et al.
(författare)
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The photosystem II-associated Cah3 in Chlamydomonas enhances the O-2 evolution rate by proton removal
- 2008
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Ingår i: EMBO Journal. - : Wiley. - 0261-4189 .- 1460-2075. ; 27:5, s. 782-791
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Tidskriftsartikel (refereegranskat)abstract
- Water oxidation in photosystem II ( PSII) is still insufficiently understood and is assumed to involve HCO3-. A Chlamydomonas mutant lacking a carbonic anhydrase associated with the PSII donor side shows impaired O-2 evolution in the absence of HCO3-. The O-2 evolution for saturating, continuous illumination (R-O2) was slower than in the wild type, but was elevated by HCO3- and increased further by Cah3. The R-O2 limitation in the absence of Cah3/HCO3- was amplified by H2O/D2O exchange, but relieved by an amphiphilic proton carrier, suggesting a role of Cah3/HCO3- in proton translocation. Chlorophyll fluorescence indicates a Cah3/HCO3- effect at the donor side of PSII. Time-resolved delayed fluorescence and O-2-release measurements suggest specific effects on proton-release steps but not on electron transfer. We propose that Cah3 promotes proton removal from the Mn complex by locally providing HCO3-, which may function as proton carrier. Without Cah3, proton removal could become rate limiting during O-2 formation and thus, limit water oxidation under high light. Our results underlie the general importance of proton release at the donor side of PSII during water oxidation.
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| 6. |
- Villarejo, Arsenio, et al.
(författare)
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Evidence for a protein transported through the secretory pathway en route to the higher plant chloroplast
- 2005
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Ingår i: Nature Cell Biology. - : Springer Nature. - 1465-7392 .- 1476-4679. ; 7:12, s. 1224-1231
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Tidskriftsartikel (refereegranskat)abstract
- In contrast to animal and fungal cells, green plant cells contain one or multiple chloroplasts, the organelle(s) in which photosynthetic reactions take place. Chloroplasts are believed to have originated from an endosymbiotic event and contain DNA that codes for some of their proteins. Most chloroplast proteins are encoded by the nuclear genome and imported with the help of sorting signals that are intrinsic parts of the polypeptides. Here, we show that a chloroplast-located protein in higher plants takes an alternative route through the secretory pathway, and becomes N-glycosylated before entering the chloroplast.
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