Effects of Anoxia and the Mitochondrion on Expression of Aerobic Nuclear COX Genes in Yeast

Dagsgaard, Chris; Taylor, Lynn E.; O’Brien, Kristin M.; Poyton, Robert O.

doi:10.1074/jbc.m009180200

Cited by 54 publications

(20 citation statements)

References 65 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Insofar as oxygen is the electron acceptor for this process, it was surprising that gene expression studies with yeast revealed that most COX genes are expressed, albeit at low levels, under anoxic conditions (31,65). Moreover, the promitochondria from anoxic yeast cells retain significant levels of the polypeptide subunits of Cco (66) and the ability to respire (67). These findings suggested a physiological role for Cco in the absence of O 2 .…”

Section: Discussionmentioning

confidence: 63%

“…Yeast cells were grown in SSG-TEA, a semisynthetic medium (66), supplemented with Tween 80, ergosterol, silicon antifoam, and amino acids and uracil, as needed (14). Aerobic cultures and precultures were grown in a controlled environment incubator shaker (New Brunswick Scientific) at 200 rpm and 28°C and harvested in midlogarithmic growth phase.…”

Section: Methodsmentioning

confidence: 99%

See 1 more Smart Citation

Oxygen-regulated isoforms of cytochrome c oxidase have differential effects on its nitric oxide production and on hypoxic signaling

Castello

Woo

Ball

et al. 2008

Proc. Natl. Acad. Sci. U.S.A.

Self Cite

104

View full text Add to dashboard Cite

Recently, it has been reported that mitochondria possess a novel pathway for nitric oxide (NO) synthesis. This pathway is induced when cells experience hypoxia, is nitrite (NO 2 ؊ )-dependent, is independent of NO synthases, and is catalyzed by cytochrome c oxidase (Cco). It has been proposed that this mitochondrially produced NO is a component of hypoxic signaling and the induction of nuclear hypoxic genes. In this study, we examine the NO 2 ؊ -dependent NO production in yeast engineered to contain alternative isoforms, Va or Vb, of Cco subunit V. Previous studies have shown that these isoforms have differential effects on oxygen reduction by Cco, and that their genes (COX5a and COX5b, respectively) are inversely regulated by oxygen. Here, we find that the Vb isozyme has a higher turnover rate for NO production than the Va isozyme and that the Vb isozyme produces NO at much higher oxygen concentrations than the Va isozyme. We have also found that the hypoxic genes CYC7 and OLE1 are induced to higher levels in a strain carrying the Vb isozyme than in a strain carrying the Va isozyme. Together, these results demonstrate that the subunit V isoforms have differential effects on NO 2 ؊ -dependent NO production by Cco and provide further support for a role of Cco in hypoxic signaling. These findings also suggest a positive feedback mechanism in which mitochondrially produced NO induces expression of COX5b, whose protein product then functions to enhance the ability of Cco to produce NO in hypoxic/anoxic cells.hypoxia ͉ mitochondria ͉ reactive oxygen species ͉ nitrite ͉ yeast I t has been known for quite some time that the mitochondrial respiratory chain is capable of generating reactive oxygen species (ROS) that account for much of the oxidative stress experienced by cells (1-3). The levels of these ROS increase when electron flow through the respiratory chain is inhibited by respiratory inhibitors (4-6) or altered by uncoupling electron transport from oxidative phosphorylation (7,8). Several studies have shown that exposure of cells and tissues to hypoxia increases ROS levels and oxidative stress (9-11). This increase in oxidative stress during exposure to hypoxia depends on a functional mitochondrial respiratory chain (10). It is currently unclear whether this increase is the result of increased generation or decreased destruction of ROS under hypoxic conditions. In yeast cells, the increase in ROS levels and oxidative stress is transient, as determined by shifting cells from normoxia to anoxia (10). During this shift, cells experience a continuum of decreasing oxygen concentrations and a transient increase in the levels of carbonylation of both mitochondrial and cytosolic protein, an increase in 8-OH-dG levels in mtDNA, and an increase in expression of the SOD1 gene. Many of the proteins that are carbonylated during a shift from normoxia to anoxia are the same proteins that are carbonylated when cells are exposed to menadione, a redox recycling agent that produces elevated intracellular levels of superoxide (12). ...

show abstract

Section: Discussionmentioning

confidence: 63%

Section: Methodsmentioning

confidence: 99%

Oxygen-regulated isoforms of cytochrome c oxidase have differential effects on its nitric oxide production and on hypoxic signaling

Castello

Woo

Ball

et al. 2008

Proc. Natl. Acad. Sci. U.S.A.

Self Cite

104

View full text Add to dashboard Cite

show abstract

“…Reduced mitochondrial structures have been observed in both dried seeds and in meristematic zones in a variety of plants (41)(42)(43). Anaerobiosis is another scenario where such protomitochondria have been proposed to exist in both plants and yeast (2,6,12,19,23). Plant studies, like those in many animals, have been hampered by the lack of extended anoxia tolerance of cells to truly observe mitochondria that have been formed in the absence of oxygen.…”

Section: Bn-polyacrylamide Gels Of Electron Transport Chainmentioning

confidence: 99%

“…Such studies have shown that mammalian mitochondria may function as oxygen sensors and secondary messengers by increasing their generation of reactive oxygen species during the early stages of oxygen deprivation (5). Induction of some "hypoxic nuclear genes" in both mammals and yeast requires mitochondrial respiration and cytochrome c oxidase has been shown to function as a key oxygen sensor during this process (6).…”

mentioning

confidence: 99%

Changes in the Mitochondrial Proteome during the Anoxia to Air Transition in Rice Focus around Cytochrome-containing Respiratory Complexes

Millar

Trend

Heazlewood

2004

Journal of Biological Chemistry

View full text Add to dashboard Cite

The ability of rice seedlings to grow from dry seed under anoxia provides a rare opportunity in a multicellular eukaryote to study the stages of mitochondrial biogenesis triggered by oxygen availability. The function and proteome of rice mitochondria synthesized under 6 days of anoxia following 1 day of air adaptation have been compared with mitochondria isolated from 7-day aerobically grown rice seedlings. Rice coleoptiles grown under anoxia, and the mitochondria isolated from them respired very slowly compared with airadapted and air-grown seedlings. Immunodetection of key mitochondrial protein markers, isoelectric focusing electrophoresis followed by SDS-PAGE to make soluble mitochondria proteome maps, and shotgun sequencing of mitochondrial proteins by liquid chromatographytandem mass spectrometry all revealed similar patterns of the major function categories of mitochondrial proteins from both anoxic and air-adapted samples. Activity analysis showed respiratory oxidases markedly increased in activity during the air adaptation of seedlings. Blue-native electrophoresis followed by SDS-PAGE of mitochondrial membrane proteins clearly showed the very low abundance of assembled b/c 1 complex and cytochrome c oxidase complex in the mitochondrial membrane in anoxic samples and the dramatic increase in the abundance of these complexes on air adaptation. Total heme content, cytochrome absorbance spectra, and the electron carrier, cytochrome c, also increased markedly on air adaptation. These results likely reflect limited heme synthesis for cytochrome assembly in the absence of oxygen and represent a discrete and reversible blockage of full mitochondrial biogenesis in this anoxia-tolerant species.

show abstract

“…Our results pointed to an exciting possibility of using CcO activity modulators for controlling myocardial injury associated with ischemia and oxidative stress conditions. Cytochrome c oxidase (CcO) 3 is the terminal oxidase of the mitochondrial electron transport chain, whose activity is modulated in response to O 2 tension and the work load of the tissue (1)(2)(3)(4)(5)(6). This rate-limiting enzyme is an important site of regulation of mitochondrial respiration and oxidative phosphorylation (7).…”

mentioning

confidence: 99%

Protein Kinase A-mediated Phosphorylation Modulates Cytochrome c Oxidase Function and Augments Hypoxia and Myocardial Ischemia-related Injury

Prabu

Anandatheerthavarada

Raza³

et al. 2006

Journal of Biological Chemistry

168

195

View full text Add to dashboard Cite

We have investigated the effects of hypoxia and myocardial ischemia/reperfusion on the structure and function of cytochrome c oxidase (CcO). Hypoxia (0.1% O 2 for 10 h) and cAMP-mediated inhibition of CcO activity were accompanied by hyperphosphorylation of subunits I, IVi1, and Vb and markedly increased reactive O 2 species production by the enzyme complex in an in vitro system that uses reduced cytochrome c as an electron donor. Both subunit phosphorylation and enzyme activity were effectively reversed by 50 nM H89 or 50 nM myristoylated peptide inhibitor (MPI), specific inhibitors of protein kinase A, but not by inhibitors of protein kinase C. In rabbit hearts subjected to global and focal ischemia, CcO activity was inhibited in a time-dependent manner and was accompanied by hyperphosphorylation as in hypoxia. Additionally, CcO activity and subunit phosphorylation in the ischemic heart were nearly completely reversed by H89 or MPI added to the perfusion medium. Hyperphosphorylation of subunits I, IVi1, and Vb was accompanied by reduced subunit contents of the immunoprecipitated CcO complex. Most interestingly, both H89 and MPI added to the perfusion medium dramatically reduced the ischemia/reperfusion injury to the myocardial tissue. Our results pointed to an exciting possibility of using CcO activity modulators for controlling myocardial injury associated with ischemia and oxidative stress conditions. Cytochrome c oxidase (CcO) 3 is the terminal oxidase of the mitochondrial electron transport chain, whose activity is modulated in response to O 2 tension and the work load of the tissue (1-6). This rate-limiting enzyme is an important site of regulation of mitochondrial respiration and oxidative phosphorylation (7). In the yeast, altered CcO activity in response to aerobic and anaerobic conditions is associated with the differential expression of the two isologs of the CcO Vb gene (8), although the precise mechanism by which the mammalian CcO modulates its activity remains unknown. Mitochondrial electron transport chain complexes are major sources of cellular ROS under both normoxic and hypoxic conditions (9, 10). Hypoxia-tolerant and hypoxia-sensitive human glioma cells exhibit distinct patterns of mitochondrial function in response to hypoxia (9, 11). Submitochondrial particles exposed to hypoxic conditions in vitro show reduced CcO activity (1,10,12). Some studies also suggest that the myocardial ischemia/reperfusion injury is manifested through altered CcO activity and reduced mitochondrial oxidative phosphorylation (13,14).Protein kinases have been suggested to play a role in the modulation of myocardial ischemia/reperfusion injury (15), although the roles of different cellular components in mediating this injury remain unclear. The presence of PKA and PKC activities in the mitochondrial inner membrane-matrix compartment and the role of PKC-mediated phosphorylation in the regulation of pyruvate dehydrogenase activity are well established (16). An 18-kDa subunit of the NADH dehydrogenase (complex I) (17)...

show abstract

Effects of Anoxia and the Mitochondrion on Expression of Aerobic Nuclear COX Genes in Yeast

Cited by 54 publications

References 65 publications

Oxygen-regulated isoforms of cytochrome c oxidase have differential effects on its nitric oxide production and on hypoxic signaling

Oxygen-regulated isoforms of cytochrome c oxidase have differential effects on its nitric oxide production and on hypoxic signaling

Changes in the Mitochondrial Proteome during the Anoxia to Air Transition in Rice Focus around Cytochrome-containing Respiratory Complexes

Protein Kinase A-mediated Phosphorylation Modulates Cytochrome c Oxidase Function and Augments Hypoxia and Myocardial Ischemia-related Injury

Contact Info

Product

Resources

About