scholarly journals Mitochondria, oxidative stress and the petite phenotype in Saccharomyces cerevisiae

2010 ◽  
Vol 31 (2) ◽  
pp. 82
Author(s):  
Anita Ayer ◽  
Ian W Dawes ◽  
Gabriel G Perrone

Oxidative stress has long been recognised as biologically important and is increasingly implicated in a variety of phenomena, such as mutation, carcinogenesis, degenerative and other diseases, inflammation, ageing, and development. The role of the mitochondrion in oxidative stress and the production of reactive oxygen species (ROS) and other radical species is well-established, with mitochondria providing a fascinating area of study within the oxidative stress field. Mitochondria are essential organelles for the viability of all eukaryotic organisms. While mitochondria perform important processes associated with oxidative phosphorylation and energy production, and numerous other metabolic processes, such as iron sulfur cluster biogenesis, lipid and amino acid synthesis, they also appear to be the largest intracellular source of ROS in aerobic cells. The steady state concentration of O2 in the mitochondrial matrix is five- to tenfold higher than in the cytosol or nuclear space according to one estimation. Therefore, mitochondrial macromolecules such as mitochondrial DNA are particularly susceptible to oxidative damage.

2017 ◽  
Vol 1861 (1) ◽  
pp. 3154-3163 ◽  
Author(s):  
Danilo di Maio ◽  
Balasubramanian Chandramouli ◽  
Robert Yan ◽  
Giuseppe Brancato ◽  
Annalisa Pastore

2008 ◽  
Vol 36 (6) ◽  
pp. 1112-1119 ◽  
Author(s):  
Sibali Bandyopadhyay ◽  
Kala Chandramouli ◽  
Michael K. Johnson

Iron–sulfur (Fe–S) clusters are present in more than 200 different types of enzymes or proteins and constitute one of the most ancient, ubiquitous and structurally diverse classes of biological prosthetic groups. Hence the process of Fe–S cluster biosynthesis is essential to almost all forms of life and is remarkably conserved in prokaryotic and eukaryotic organisms. Three distinct types of Fe–S cluster assembly machinery have been established in bacteria, termed the NIF, ISC and SUF systems, and, in each case, the overall mechanism involves cysteine desulfurase-mediated assembly of transient clusters on scaffold proteins and subsequent transfer of pre-formed clusters to apo proteins. A molecular level understanding of the complex processes of Fe–S cluster assembly and transfer is now beginning to emerge from the combination of in vivo and in vitro approaches. The present review highlights recent developments in understanding the mechanism of Fe–S cluster assembly and transfer involving the ubiquitous U-type scaffold proteins and the potential roles of accessory proteins such as Nfu proteins and monothiol glutaredoxins in the assembly, storage or transfer of Fe–S clusters.


2015 ◽  
Vol 112 (44) ◽  
pp. 13735-13740 ◽  
Author(s):  
Anna Moseler ◽  
Isabel Aller ◽  
Stephan Wagner ◽  
Thomas Nietzel ◽  
Jonathan Przybyla-Toscano ◽  
...  

The iron-sulfur cluster (ISC) is an ancient and essential cofactor of many proteins involved in electron transfer and metabolic reactions. In Arabidopsis, three pathways exist for the maturation of iron-sulfur proteins in the cytosol, plastids, and mitochondria. We functionally characterized the role of mitochondrial glutaredoxin S15 (GRXS15) in biogenesis of ISC containing aconitase through a combination of genetic, physiological, and biochemical approaches. Two Arabidopsis T-DNA insertion mutants were identified as null mutants with early embryonic lethal phenotypes that could be rescued by GRXS15. Furthermore, we showed that recombinant GRXS15 is able to coordinate and transfer an ISC and that this coordination depends on reduced glutathione (GSH). We found the Arabidopsis GRXS15 able to complement growth defects based on disturbed ISC protein assembly of a yeast Δgrx5 mutant. Modeling of GRXS15 onto the crystal structures of related nonplant proteins highlighted amino acid residues that after mutation diminished GSH and subsequently ISC coordination, as well as the ability to rescue the yeast mutant. When used for plant complementation, one of these mutant variants, GRXS15K83/A, led to severe developmental delay and a pronounced decrease in aconitase activity by approximately 65%. These results indicate that mitochondrial GRXS15 is an essential protein in Arabidopsis, required for full activity of iron-sulfur proteins.


2008 ◽  
Vol 190 (13) ◽  
pp. 4512-4520 ◽  
Author(s):  
Jiae Yun ◽  
Byeonghwa Jeon ◽  
Yi-Wen Barton ◽  
Paul Plummer ◽  
Qijing Zhang ◽  
...  

ABSTRACT DksA is well known for its regulatory role in the transcription of rRNA and genes involved in amino acid synthesis in many bacteria. DksA has also been reported to control expression of virulence genes in pathogenic bacteria. Here, we elucidated the roles of a DksA-like protein (CJJ81176_0160, Cj0125c) in the pathogenesis of Campylobacter jejuni. As in other bacteria, transcription of stable RNA was repressed by the DksA-like protein under stress conditions in C. jejuni. Transcriptomic and proteomic analyses of C. jejuni 81-176 and an isogenic mutant lacking the DksA-like protein showed differential expression of many genes involved in amino acid metabolism, iron-related metabolism, and other metabolic reactions. Also, the C. jejuni DksA-like protein mutant exhibited a decreased ability to invade intestinal cells and induce release of interleukin-8 from intestinal cells. These results suggest that the DksA-like protein plays an important regulatory role in diverse metabolic events and the virulence of C. jejuni.


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