Rieske Protein (rieske + protein)

Distribution by Scientific Domains


Selected Abstracts


Proteomic Identification of the Involvement of the Mitochondrial Rieske Protein in Epilepsy

EPILEPSIA, Issue 3 2005
Heike Junker
Summary:,Purpose: Kindled seizures are widely used to model epileptogenesis, but the molecular mechanisms underlying the attainment of kindling status are largely unknown. Recently we showed that achievement of kindling status in the Sprague,Dawley rat is associated with a critical developmental interval of 25 ± 1 days; the identification of this long, well-defined developmental interval for inducing kindling status makes possible a dissection of the cellular and genetic events underlying this phenomenon and its relation to normal and pathologic brain function. Methods: By using proteomics on cerebral tissue from our new rat kindling model, we undertook a global analysis of protein expression in kindled animals. Some of the identified proteins were further investigated by using immunohistochemistry. Results: We report the identification of a modified variant of the Rieske iron-sulfur protein, a component of the mitochondrial cytochrome bc1 complex, whose isoelectric point is shifted toward more alkaline values in the hippocampus of kindled rats. By immunohistochemistry, the Rieske protein is well expressed in the hippocampus, except in the CA1 subfield, an area of selective vulnerability to seizures in humans and animal models. We also noted an asymmetric, selective expression of the Rieske protein in the subgranular neurons of the dorsal dentate gyrus, a region implicated in neurogenesis. Conclusions: These results indicate that the Rieske protein may play a role in the response of neurons to seizure activity and could give important new insights into the molecular pathogenesis of epilepsy. [source]


Identification and characterization of cytochrome bc1 subcomplexes in mitochondria from yeast with single and double deletions of genes encoding cytochrome bc1 subunits

FEBS JOURNAL, Issue 17 2007
Vincenzo Zara
We have examined the status of the cytochrome bc1 complex in mitochondrial membranes from yeast mutants in which genes for one or more of the cytochrome bc1 complex subunits were deleted. When membranes from wild-type yeast were resolved by native gel electrophoresis and analyzed by immunodecoration, the cytochrome bc1 complex was detected as a mixed population of enzymes, consisting of cytochrome bc1 dimers, and ternary complexes of cytochrome bc1 dimers associated with one and two copies of the cytochrome c oxidase complex. When membranes from the deletion mutants were resolved and analyzed, the cytochrome bc1 dimer was not associated with the cytochrome c oxidase complex in many of the mutant membranes, and membranes from some of the mutants contained a common set of cytochrome bc1 subcomplexes. When these subcomplexes were fractionated by SDS/PAGE and analyzed with subunit-specific antibodies, it was possible to recognize a subcomplex consisting of cytochrome b, subunit 7 and subunit 8 that is apparently associated with cytochrome c oxidase early in the assembly process, prior to acquisition of the remaining cytochrome bc1 subunits. It was also possible to identify a subcomplex consisting of subunit 9 and the Rieske protein, and two subcomplexes containing cytochrome c1 associated with core protein 1 and core protein 2, respectively. The analysis of all the cytochrome bc1 subcomplexes with monospecific antibodies directed against Bcs1p revealed that this chaperone protein is involved in a late stage of cytochrome bc1 complex assembly. [source]


Assembly of the Rieske iron,sulphur protein into the cytochrome bf complex in thylakoid membranes of isolated pea chloroplasts

FEBS JOURNAL, Issue 2 2000
Aliki Kapazoglou
The assembly of the Rieske iron,sulphur protein into the cytochrome bf complex was examined following import of 35S-labeled precursor protein by isolated pea chloroplasts. Rieske protein assembled into the cytochrome bf complex was resolved from unassembled Rieske protein and from other membrane complexes by nondenaturing gel electrophoresis of dodecyl maltoside-solubilized thylakoid membranes. Four mutant forms of the Rieske protein were able to assemble into the cytochrome bf complex in isolated chloroplasts. These were a triple substitution mutant, C107S/H109R/C112S, replacing conserved residues involved in the ligation of the [2Fe-2S] centre; the mutant ,45,52 which removed a glycine-rich region predicted to form a flexible hinge between the hydrophobic membrane-associated region and the hydrophilic lumenal domain; and mutants ,168,173 and ,177,179 which removed two C-terminal regions, which are highly conserved in chloroplast and cyanobacterial Rieske proteins. This indicates that the [2Fe,2S] cluster, the glycine-rich region and the C-terminal region are not essential for stable assembly of the Rieske protein into the cytochrome bf complex in isolated chloroplasts. [source]


Structure of T4moC, the Rieske-type ferredoxin component of toluene 4-monooxygenase

ACTA CRYSTALLOGRAPHICA SECTION D, Issue 5 2006
Luke A. Moe
The structure of the Rieske-type ferredoxin (T4moC) from toluene 4-monooxygenase was determined by X-ray crystallography in the [2Fe,2S]2+ state at a resolution of 1.48,Å using single-wavelength anomalous dispersion phasing with the [2Fe,2S] center. The structure consists of ten ,-strands arranged into the three antiparallel ,-sheet topology observed in all Rieske proteins. Trp69 of T4moC is adjacent to the [2Fe,­2S] centre, which displaces a loop containing the conserved Pro81 by ,8,Å away from the [2Fe,2S] cluster compared with the Pro loop in the closest structural and functional homolog, the Rieske-type ferredoxin BphF from biphenyl dioxygenase. In addition, T4moC contains five hydrogen bonds to the [2Fe,2S] cluster compared with three hydrogen bonds in BphF. Moreover, the electrostatic surface of T4moC is distinct from that of BphF. These structural differences are identified as possible contributors to the evolutionary specialization of soluble Rieske-type ferredoxins between the diiron monooxygenases and cis -dihydrodiol-forming dioxygenases. [source]