Changes in the redox state of cytochrome b5 in the outer mitochondrial membrane as a result of interaction with lipid intermediates: Role of cytochrome c

2013 ◽  
Vol 453 (1) ◽  
pp. 292-296 ◽  
Author(s):  
A. D. Doroshchuk ◽  
L. F. Dmitriev
Keyword(s):  
Cytochrome C ◽  
Mitochondrial Membrane ◽  
Redox State ◽  
Cytochrome B5 ◽  
Outer Mitochondrial Membrane

scholarly journals Mitochondria-Associated Membranes (MAMs) are involved in Bax mitochondrial localization and cytochrome c release

2018 ◽  
Author(s):  
Alexandre Légiot ◽  
Claire Céré ◽  
Thibaud Dupoiron ◽  
Mohamed Kaabouni ◽  
Stéphen Manon
Keyword(s):  
Endoplasmic Reticulum ◽  
Cytochrome C ◽  
Mitochondrial Membrane ◽  
Human Protein ◽  
Outer Mitochondrial Membrane ◽  
Yeast Mutant ◽  
Mitochondrial Localization ◽  
Cytochrome C Release ◽  
Apoptotic Protein

AbstractThe distribution of the pro-apoptotic protein Bax in the outer mitochondrial membrane (OMM) is a central point of regulation of apoptosis. It is now widely recognized that parts of the endoplasmic reticulum (ER) are closely associated to the OMM, and are actively involved in different signalling processes. We adressed a possible role of these domains, called Mitochondria-Associated Membranes (MAMs) in Bax localization and fonction, by expressing the human protein in a yeast mutant deleted of MDM34, a ERMES component (ER-Mitochondria Encounter Structure). By affecting MAMs stability, the deletion of MDM34 altered Bax mitochondrial localization, and decreased its capacity to release cytochrome c. Furthermore, the deletion of MDM34 decreased the size of an uncompletely released, MAMs-associated pool of cytochrome c.

Efficient Coupled Oxidation of Heme Performed by the H63M Variant of Outer Mitochondrial Membrane Cytochrome b5

1998 ◽  
Vol 27 (4) ◽  
pp. 353-354 ◽  
Author(s):  
Juan Carlos Rodríguez ◽  
Thamara Desilva ◽  
Mario Rivera
Keyword(s):  
Mitochondrial Membrane ◽  
Cytochrome B5 ◽  
Outer Mitochondrial Membrane

scholarly journals Which Domain of VDAC2 is Necessary for Bak Insertion to the Outer Mitochondrial Membrane and tBid - Induced Cytochrome C Release?

2013 ◽  
Vol 104 (2) ◽  
pp. 656a ◽  
Author(s):  
Shamim Naghdi ◽  
Peter Varnai ◽  
Soumya Sinha Roy ◽  
Laszlo Hunyady ◽  
Gyorgy Hajnoczky
Keyword(s):  
Cytochrome C ◽  
Mitochondrial Membrane ◽  
Outer Mitochondrial Membrane ◽  
Cytochrome C Release

scholarly journals How does the TOM complex mediate insertion of precursor proteins into the mitochondrial outer membrane?

2005 ◽  
Vol 171 (3) ◽  
pp. 419-423 ◽  
Author(s):  
Doron Rapaport
Keyword(s):  
Membrane Proteins ◽  
Outer Membrane ◽  
Mitochondrial Membrane ◽  
Mitochondrial Outer Membrane ◽  
Outer Face ◽  
Outer Mitochondrial Membrane ◽  
Lipid Core ◽  
Tom Complex ◽  
Precursor Proteins

A multisubunit translocase of the outer mitochondrial membrane (TOM complex) mediates both the import of mitochondrial precursor proteins into the internal compartments of the organelle and the insertion of proteins residing in the mitochondrial outer membrane. The proposed β-barrel structure of Tom40, the pore-forming component of the translocase, raises the question of how the apparent uninterrupted β-barrel topology can be compatible with a role of Tom40 in releasing membrane proteins into the lipid core of the bilayer. In this review, I discuss insertion mechanisms of proteins into the outer membrane and present alternative models based on the opening of a multisubunit β-barrel TOM structure or on the interaction of outer membrane precursors with the outer face of the Tom40 β-barrel structure.

scholarly journals Reduction of ferric haemoproteins by tetrahydropterins: a kinetic study

2005 ◽  
Vol 392 (3) ◽  
pp. 583-587 ◽  
Author(s):  
Chantal Capeillere-Blandin ◽  
Delphine Mathieu ◽  
Daniel Mansuy
Keyword(s):  
Electron Transfer ◽  
Cytochrome C ◽  
Cytochrome B5 ◽  
Reduction Rate ◽  
Cation Radical ◽  
Order Reduction ◽  
Reduction Potentials ◽  
Electron Reduction ◽  
The One

We previously showed that one-electron transfer from tetrahydropterins to iron porphyrins is a very general reaction, with formation of an intermediate cation radical similar to the one detected in NO synthase. As a model reaction, the rates of reduction of eight haemoproteins by diMePH4 (6,7-dimethyltetrahydropterin) have been studied and correlated with their one-electron reduction potentials, Em (FeIII/FeII). On the basis of kinetic data analyses, a bimolecular collisional mechanism is proposed for the electron transfer from diMePH4 to ferrihaemoproteins. Haemoproteins with reduction potentials below −160 mV were shown not to be reduced by diMePH4 to the corresponding ferrohaemoproteins. For haemoproteins with reduction potentials more positive than −160 mV, such as chloroperoxidase, cytochrome b5, methaemoglobin and cytochrome c, there was a good correlation between the second-order reduction rate constant and the redox potential, Em (FeIII/FeII):The rate of reduction of cytochrome c by BH4 [(6R)-5,6,7,8-tetrahydrobiopterin] was determined to be similar to that of the reduction of cytochrome c by diMePH4. These results confirm the role of tetrahydropterins as one-electron donors to FeIII porphyrins.

scholarly journals Role of cytochrome c heme lyase in mitochondrial import and accumulation of cytochrome c in Saccharomyces cerevisiae.

1991 ◽  
Vol 11 (11) ◽  
pp. 5487-5496 ◽  
Author(s):  
M E Dumont ◽  
T S Cardillo ◽  
M K Hayes ◽  
F Sherman
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Cytochrome C ◽  
Mitochondrial Membrane ◽  
Intermembrane Space ◽  
Inner Mitochondrial Membrane ◽  
Yeast Saccharomyces Cerevisiae ◽  
Apocytochrome C ◽  
Cytochrome C Heme Lyase

Heme is covalently attached to cytochrome c by the enzyme cytochrome c heme lyase. To test whether heme attachment is required for import of cytochrome c into mitochondria in vivo, antibodies to cytochrome c have been used to assay the distributions of apo- and holocytochromes c in the cytoplasm and mitochondria from various strains of the yeast Saccharomyces cerevisiae. Strains lacking heme lyase accumulate apocytochrome c in the cytoplasm. Similar cytoplasmic accumulation is observed for an altered apocytochrome c in which serine residues were substituted for the two cysteine residues that normally serve as sites of heme attachment, even in the presence of normal levels of heme lyase. However, detectable amounts of this altered apocytochrome c are also found inside mitochondria. The level of internalized altered apocytochrome c is decreased in a strain that completely lacks heme lyase and is greatly increased in a strain that overexpresses heme lyase. Antibodies recognizing heme lyase were used to demonstrate that the enzyme is found on the outer surface of the inner mitochondrial membrane and is not enriched at sites of contact between the inner and outer mitochondrial membranes. These results suggest that apocytochrome c is transported across the outer mitochondrial membrane by a freely reversible process, binds to heme lyase in the intermembrane space, and is then trapped inside mitochondria by an irreversible conversion to holocytochrome c accompanied by folding to the native conformation. Altered apocytochrome c lacking the ability to have heme covalently attached accumulates in mitochondria only to the extent that it remains bound to heme lyase.

Hemin Is Kinetically Trapped in Cytochrome b5 from Rat Outer Mitochondrial Membrane

2000 ◽  
Vol 273 (2) ◽  
pp. 467-472 ◽  
Author(s):  
Svetlana Silchenko ◽  
Michelle L. Sippel ◽  
Olga Kuchment ◽  
David R. Benson ◽  
A.Grant Mauk ◽  
...  
Keyword(s):  
Mitochondrial Membrane ◽  
Cytochrome B5 ◽  
Outer Mitochondrial Membrane
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