Michael P Murphy

..RECENT ADVANCES: Here, mitochondrial thiol systems are reviewed, and areas of uncertainty are pointed out, focusing on recent developments in our understanding of their roles...

..Considerable progress is being made in addressing these issues, and here we survey some recent developments for those contemplating research in this area...

..These findings strengthen the growing view that elevated mitochondrial ROS contributes to the etiology of the metabolic syndrome and suggest a potential therapeutic role for mitochondria-targeted antioxidants...

..These findings are consistent with roles for mitochondrial vicinal dithiol proteins in antioxidant defence and redox signalling and these methodologies will enable these roles to be explored...

..More generally, the development of SNO-DIGE facilitates robust investigation of protein S-nitrosation across the proteome...

..This method facilitates the investigation of mitochondrial H(2)O(2) in fly models of pathology and metabolic alteration, and it can also be extended to assess mitochondrial H(2)O(2) production in mouse and cell culture studies...

..These results support the idea that selectively targeting NO(*) donors to mitochondria is an effective strategy to reversibly modulate respiration and to protect mitochondria against ischemia-reperfusion injury...

..Here, we discuss a number of these approaches and their application to the identification of a variety of cysteine-centered redox modifications...

..Here we review the mechanisms and physiological significance of the glutathionylation of mitochondrial thiol proteins...

..Importantly, this method is not only applicable to studies in isolated mitochondria but can also be applied to more complicated systems such as intact cells and perhaps even whole organisms...

..Therefore, exposed protein thiols are the dominant free thiol within the cell and may play a critical role in intracellular antioxidant defences against oxidative damage...

..Here we outline some of the approaches that can be used to accomplish these goals and thereby infer the multiple roles of mammalian mitochondrial protein thiols in antioxidant defense and redox signaling...

..Thiol redox modification affected enzyme activity, suggesting that the reversible modification of enzyme activity by ROS from the respiratory chain may be an important and unexplored mode of mitochondrial redox signaling...

..Furthermore, as TEMPOL is also reduced to a hydroxylamine in vivo, many of its antioxidant effects may also be mediated by its hydroxylamine...

..To help understand how Coenzyme Q contributes to both mitochondrial oxidative damage and antioxidant defences, we have reviewed its antioxidant and prooxidant properties...

..Using a DeltaCoQ double-knockout library we identified a number of genes that decrease the ability of yeast to grow on exogenous CoQ. Here we suggest that CoQ or its redox state may be a signal for growth during the shift to respiration...

..Here, we outline the background to these strategies and discuss how antioxidants targeted to mitochondria, or selective mitochondrial uncoupling, may be potential therapies for diabetes...

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..Therefore, mitochondria-targeted single-chain ZFNs are a promising candidate approach for the treatment of mtDNA diseases...

..Superoxide releases iron from iron-sulfur center proteins, which then generates carbon-centered radicals that initiate lipid peroxidation, yielding breakdown products that activate UCPs...

..These data resolve reported discrepancies on the effect of NO on HIF-1alpha stability at low oxygen concentrations and suggest that inhibition of mitochondrial respiration by NO may affect oxygen sensing by HIF-1 in vivo...

..Here we review the background and work to date on this class of mitochondria-targeted antioxidants...

..This is a proof of principle that it is possible to target and alter mtDNA in a sequence-specific manner by using zinc finger technology...

..Here we outline some of the background to the development of these compounds...

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..This method of directing PNAs into cells is a significant improvement on current procedures and will facilitate in vitro and pharmacological applications of PNAs...

..Here we review mitochondrial thiol metabolism, outline how NO and its metabolites interact with thiols, and discuss the implications of these reactions for mitochondrial and cell function...

..DNA damage is present in both genomic and mitochondrial DNA in atherosclerosis. However, whether DNA damage itself promotes atherosclerosis, or is simply a byproduct of the risk factors that promote atherosclerosis, is unknown...

..This inability to alkylate mtDNA in situ has significant implications for the design of therapies for mtDNA diseases and for studies on the packaging, expression and turnover of mtDNA in general...

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..A better understanding of these processes will eventually clarify why particular mtDNA mutations cause defined syndromes in some cases but not in others and why the same mutation can lead to different phenotypes...

..This combination of a hierarchical framework and the methodologies of MCA may prove useful both for thinking about aging and for analyzing it experimentally...

..The protocol can be completed within a week, although time-consuming DNA cloning steps may extend this...