Cardiolipin-dependent formation of mitochondrial respiratory supercomplexes

doi:10.1016/j.chemphyslip.2013.10.012

Chemistry and Physics of Lipids

Volume 179, April 2014, Pages 42-48

https://doi.org/10.1016/j.chemphyslip.2013.10.012 Get rights and content

Highlights

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Organization of supercomplexes (SCs) with integral cardiolipin (CL) is analyzed.
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CL content in different purified SCs correlated with spaces inside SCs is discussed.
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New in vitro SC reconstitution system using CL-containing liposomes is described.
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Importance of exchangeable CL bound on the membrane-exposed SC surfaces is discussed.
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Change in CL level as a potential metabolic signal for SC dynamics is postulated.

Abstract

The organization of individual respiratory Complexes I, III, and IV (mammalian cells) or III and IV (yeast) of the mitochondria into higher order supercomplexes (SCs) is generally accepted. However, the factors that regulate SC formation and the functional significance of SCs are not well understood. The mitochondrial signature phospholipid cardiolipin (CL) plays a central role in formation and stability of respiratory SCs from yeast to man. Studies in yeast mutants in which the CL level can be regulated displayed a direct correlation between CL levels and SC formation. Disease states in which CL levels are reduced also show defects in SC formation. Three-dimensional density maps of yeast and bovine SCs by electron cryo-microscopy show gaps between the transmembrane-localized interfaces of individual complexes consistent with the large excess of CL in SCs over that integrated into the structure of individual respiratory complexes. Finally, the yeast SC composed of Complex III and two Complexes IV was reconstituted in liposomes from purified individual complexes containing integrated CLs. Reconstitution was wholly dependent on inclusion of additional CL in the liposomes. Therefore, non-integral CL molecules play an important role in SC formation and may be involved in regulation of SC stability under metabolic conditions where CL levels fluctuate.

Introduction

The anionic phospholipid cardiolipin (CL), also called diphosphatidylglycerol, (1,3-bis(sn-3′-phosphatidyl)-sn-glycerol), is uniquely localized to energy-transducing membranes, which couple generation of an electrochemical potential with ATP synthesis and substrate transport. In eukaryotes CL is a signature phospholipid of mitochondria. The unique structure of CL is composed of two phosphates, four fatty acids, three chiral centers and a free central hydroxyl (Fig. 1), which has been suggested to serve as a proton sink. In animals and higher plants the majority of acyl chains of CL contain polyunsaturated fatty acids with 18 carbons, while in Saccharomyces cerevisiae (hereafter referred to as yeast) the fatty acids are 16 and 18 carbon monounsaturated chains (Schlame and Ren, 2009). CL interacts with many membrane proteins affecting their activity, stability, level of aggregation, and compartmentalization. In this review we will focus on the specific role CL plays in organization and function of the mitochondrial respiratory chain.

Section snippets

Synthesis of CL

The function and synthesis of mitochondrial lipids in mammalian cells and yeast are highly homologous. Yeast cells have a distinct research advantage over higher eukaryotes in ease of growth and genetic manipulation coupled with viability in the face of dramatic alterations in mitochondrial phospholipid composition. In yeast, CL and its precursor phosphatidylglycerol (PG) are synthesized from the common precursor phosphatidic acid (Fig. 1) by mitochondrial-localized enzymes that are encoded by

Mitochondrial respiratory chain organization and function

In mammalian mitochondria the respiratory chain is composed of four multi-subunit electron transfer protein complexes: Complex I (CI, NADH:ubiquinone oxidoreductase), Complex II (succinate:ubiquinone oxidoreductase), Complex III¹ or cytochrome bc₁ complex (CIII, ubiqunol:cytochrome c oxidoreductase), Complex IV (CIV, cytochrome c oxidase)

Direct involvement of CL in SC formation and pathological consequences

The role of CL was first demonstrated in the formation of the yeast tetrameric SC (III₂IV₂) using BN- and CN-PAGE of digitonin extracts of mitochondria and kinetic analysis of substrate oxidation by the respiratory chain in intact mitochondria. In yeast Δcrd1 null mutants lacking CL, but containing elevated amounts of its precursor PG, there was no formation of the stable III₂IV₂ SC or substrate channeling of cytochrome c in contrast to studies with the wild type strain containing CL (

Insights from structural analysis of SCs

Analysis of the structural organization of respiratory SCs can identify domains of individual complexes oriented toward each other, estimate distances between these domains, examine sites of protein contact, identify positions of tightly bound CL, and predict positions of loosely bound CLs. Three-dimensional (3D) density maps of the bovine heart respirasome (I₁III₂IV₁) were obtained by cryo-electron tomography (Dudkina et al., 2011) of digitonin-solubilized SC and by cryo-electron microscopy

In vitro and in silico CL-dependent reconstitution of SCs

To further study the role of CL, which may fill the spaces between transmembrane domains of CIII and CIV in the yeast III₂IV₂ SC, a minimal system for in vitro reconstitution of the SC dependent on added lipids was developed (Bázan et al., 2013). CIII and CIV were purified using dodecyl maltoside, which dissociates the SC and removes all but tightly bound and structurally integrated lipids. The purified individual complexes contained mostly integrated CL, as was determined by quantitative

Summary and future directions

The organization of individual respiratory complexes into higher order structures or SCs to form a functional respirasome has become generally accepted. These SCs contain additional CLs over those previously observed to be integrated into the structure of the individual complexes. 3D density maps of bovine and yeast SCs obtained by cryo-EM reveal spaces between the transmembrane domains of neighboring individual complexes that most likely contain many additional lipid molecules. Kinetic and

Acknowledgements

This work was supported in part by National Institutes of Health Grant GM R01 GM56389 and the John Dunn Research Foundation to W. D.

References (60)

R. Acin-Perez et al.
Respiratory active mitochondrial supercomplexes
Mol. Cell
(2008)
S. Bázan et al.
Cardiolipin-dependent reconstitution of respiratory supercomplexes from purified Saccharomyces cerevisiae complexes III and IV
J. Biol. Chem.
(2013)
A. Beranek et al.
Identification of a cardiolipin-specific phospholipase encoded by the gene CLD1 (YGR110W) in yeast
J. Biol. Chem.
(2009)
L. Bottinger et al.
Phosphatidylethanolamine and cardiolipin differentially affect the stability of mitochondrial respiratory chain supercomplexes
J. Mol. Biol.
(2012)
H. Boumans et al.
The respiratory chain in yeast behaves as a single functional unit
J. Biol. Chem.
(1998)
B. Chance et al.
Respiratory enzymes in oxidative phosphorylation. IV. The respiratory chain
J. Biol. Chem.
(1955)
Y.C. Chen et al.
Identification of a protein mediating respiratory supercomplex stability
Cell Metab.
(2012)
D.V. Dibrova et al.
Evolution of cytochrome bc complexes: from membrane-anchored dehydrogenases of ancient bacteria to triggers of apoptosis in vertebrates
Biochim. Biophys. Acta
(2013)
J. Dudek et al.
Cardiolipin deficiency affects respiratory chain function and organization in an induced pluripotent stem cell model of Barth syndrome
Stem Cell Res.
(2013)
N.V. Dudkina et al.
Structure and function of mitochondrial supercomplexes
Biochim. Biophys. Acta
(2010)

L.A. Gomez et al.

Age-related decline in mitochondrial bioenergetics: does supercomplex destabilization determine lower oxidative capacity and higher superoxide production?

Semin. Cell Dev. Biol.

(2012)

F. Gonzalvez et al.

Barth syndrome: cellular compensation of mitochondrial dysfunction and apoptosis inhibition due to changes in cardiolipin remodeling linked to tafazzin (TAZ) gene mutation

Biochim. Biophys. Acta

(2013)

T.H. Haines

A new look at Cardiolipin

Biochim. Biophys. Acta

(2009)

J. Heinemeyer et al.

A structural model of the cytochrome C reductase/oxidase supercomplex from yeast mitochondria

J. Biol. Chem.

(2007)

C. Hunte et al.

Protonmotive pathways and mechanisms in the cytochrome bc₁ complex

FEBS Lett.

(2003)

A.S. Joshi et al.

Cellular functions of cardiolipin in yeast

Biochim. Biophys. Acta

(2009)

G. Li et al.

New insights into the regulation of cardiolipin biosynthesis in yeast: implications for Barth syndrome

Biochim. Biophys. Acta

(2007)

L. Ma et al.

The human TAZ gene complements mitochondrial dysfunction in the yeast taz1Δ mutant. Implications for Barth syndrome

J. Biol. Chem.

(2004)

M. McKenzie et al.

Mitochondrial respiratory chain supercomplexes are destabilized in Barth Syndrome patients

J. Mol. Biol.

(2006)

E. Mileykovskaya et al.

Cardiolipin membrane domains in prokaryotes and eukaryotes

Biochim. Biophys. Acta

(2009)

E. Mileykovskaya et al.

Arrangement of the respiratory chain complexes in Saccharomyces cerevisiae supercomplex III₂IV₂ revealed by single particle cryo-electron microscopy

J. Biol. Chem.

(2012)

C. Morin et al.

Anoxia-reoxygenation-induced cytochrome c and cardiolipin release from rat brain mitochondria

Biochem. Biophys. Res. Commun.

(2003)

H. Palsdottir et al.

Lipids in membrane protein structures

Biochim. Biophys. Acta

(2004)

G. Paradies et al.

Mitochondrial dysfunction in brain aging: role of oxidative stress and cardiolipin

Neurochem. Int.

(2011)

K. Pfeiffer et al.

Cardiolipin stabilizes respiratory chain supercomplexes

J. Biol. Chem.

(2003)

M. Schlame et al.

Barth syndrome, a human disorder of cardiolipin metabolism

FEBS Lett.

(2006)

M. Schlame et al.

The role of cardiolipin in the structural organization of mitochondrial membranes

Biochim. Biophys. Acta

(2009)

F. Sun et al.

Revealing various coupling of electron transfer and proton pumping in mitochondrial respiratory chain

Curr. Opin. Struct. Biol.

(2013)

Y. Tamura et al.

Tam41 is a CDP-diacylglycerol synthase required for cardiolipin biosynthesis in mitochondria

Cell Metab.

(2013)

M. Vukotic et al.

Rcf1 mediates cytochrome oxidase assembly and respirasome formation, revealing heterogeneity of the enzyme complex

Cell Metab.

(2012)

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Cardiolipin-dependent formation of mitochondrial respiratory supercomplexes

Highlights

Abstract

Introduction

Section snippets

Synthesis of CL

Mitochondrial respiratory chain organization and function

Direct involvement of CL in SC formation and pathological consequences

Insights from structural analysis of SCs

In vitro and in silico CL-dependent reconstitution of SCs

Summary and future directions

Acknowledgements

Mol. Cell

J. Biol. Chem.

J. Biol. Chem.

J. Mol. Biol.

J. Biol. Chem.

J. Biol. Chem.

Cell Metab.

Biochim. Biophys. Acta

Stem Cell Res.

Biochim. Biophys. Acta

Semin. Cell Dev. Biol.

Biochim. Biophys. Acta

Biochim. Biophys. Acta

J. Biol. Chem.

FEBS Lett.

Biochim. Biophys. Acta

Biochim. Biophys. Acta

J. Biol. Chem.

J. Mol. Biol.

Biochim. Biophys. Acta

J. Biol. Chem.

Biochem. Biophys. Res. Commun.

Biochim. Biophys. Acta

Neurochem. Int.

J. Biol. Chem.

FEBS Lett.

Biochim. Biophys. Acta

Curr. Opin. Struct. Biol.

Cell Metab.

Cell Metab.