Mechanisms and physiological impact of the dual localization of mitochondrial intermembrane space proteins

2014 ◽  
Vol 42 (4) ◽  
pp. 952-958 ◽  
Author(s):  
Carmelina Petrungaro ◽  
Jan Riemer
Keyword(s):  
Oxidative Stress ◽  
Mitochondrial Function ◽  
The Other ◽  
Yeast Cells ◽  
Eukaryotic Cells ◽  
Intermembrane Space ◽  
Dual Localization ◽  
Mitochondrial Intermembrane Space ◽  
Physiological Impact ◽  
Cellular Compartments

Eukaryotic cells developed diverse mechanisms to guide proteins to more than one destination within the cell. Recently, the proteome of the IMS (intermembrane space) of mitochondria of yeast cells was identified showing that approximately 20% of all soluble IMS proteins are dually localized to the IMS, as well as to other cellular compartments. Half of these dually localized proteins are important for oxidative stress defence and the other half are involved in energy homoeostasis. In the present review, we discuss the mechanisms leading to the dual localization of IMS proteins and the implications for mitochondrial function.

scholarly journals Phosphatidylserine transport by Ups2–Mdm35 in respiration-active mitochondria

2016 ◽  
Vol 214 (1) ◽  
pp. 77-88 ◽  
Author(s):  
Non Miyata ◽  
Yasunori Watanabe ◽  
Yasushi Tamura ◽  
Toshiya Endo ◽  
Osamu Kuge
Keyword(s):  
Yeast Cells ◽  
Intermembrane Space ◽  
Diauxic Shift ◽  
Inner Membrane ◽  
Mitochondrial Inner Membrane ◽  
Mitochondrial Functions ◽  
Phospholipid Transfer ◽  
Metabolic Transition ◽  
Mitochondrial Intermembrane Space

Phosphatidylethanolamine (PE) is an essential phospholipid for mitochondrial functions and is synthesized mainly by phosphatidylserine (PS) decarboxylase at the mitochondrial inner membrane. In Saccharomyces cerevisiae, PS is synthesized in the endoplasmic reticulum (ER), such that mitochondrial PE synthesis requires PS transport from the ER to the mitochondrial inner membrane. Here, we provide evidence that Ups2–Mdm35, a protein complex localized at the mitochondrial intermembrane space, mediates PS transport for PE synthesis in respiration-active mitochondria. UPS2- and MDM35-null mutations greatly attenuated conversion of PS to PE in yeast cells growing logarithmically under nonfermentable conditions, but not fermentable conditions. A recombinant Ups2–Mdm35 fusion protein exhibited phospholipid-transfer activity between liposomes in vitro. Furthermore, UPS2 expression was elevated under nonfermentable conditions and at the diauxic shift, the metabolic transition from glycolysis to oxidative phosphorylation. These results demonstrate that Ups2–Mdm35 functions as a PS transfer protein and enhances mitochondrial PE synthesis in response to the cellular metabolic state.

scholarly journals Compartmentation of cellular activities

2007 ◽  
Vol 28 (2) ◽  
pp. 64
Author(s):  
Trevor Lithgow
Keyword(s):  
Protein Transport ◽  
Yeast Cells ◽  
Yeast Genome ◽  
Intermembrane Space ◽  
Yeast Saccharomyces Cerevisiae ◽  
Technological Advances ◽  
The Matrix ◽  
Cellular Compartments ◽  
New Applications ◽  
Yeast Mutants

In the yeast Saccharomyces cerevisiae, almost one third of cellular function is concerned with maintaining the compartmentation of cellular activities. From classic studies in yeast genetics we have come to understand a great deal of the processes driving the delivery of proteins into these compartments and the metabolic advantages that this provides. With the publication of the yeast genome sequence, ?-omics? level studies began to provide further detail on the compartmentation of yeast cells. Very recent technological advances, including new applications in mass spectrometry, NMR, cryo-electron microscopy and the use of live-cell imaging have also been applied to yeast, because of the comparative analyses that can be done on yeast mutants. The mitochondrion is a complex compartment, carrying more than a thousand proteins that must be transported into and then distributed between, four sub-mitochondrial compartments. Essential molecular machinery in the outer and inner membranes, the intermembrane space and the matrix of mitochondria, drive protein transport, sorting and assembly. A glimpse of how S. cerevisiae and other microbes have provided understanding of cellular compartments is the aim of this review.

scholarly journals Mitochondrial Protein Oxidation in Yeast Mutants Lacking Manganese-(MnSOD) or Copper- and Zinc-containing Superoxide Dismutase (CuZnSOD)

2004 ◽  
Vol 279 (50) ◽  
pp. 51817-51827 ◽  
Author(s):  
Kristin M. O'Brien ◽  
Reinhard Dirmeier ◽  
Marcella Engle ◽  
Robert O. Poyton
Keyword(s):  
Oxidative Stress ◽  
Superoxide Dismutase ◽  
Stationary Phases ◽  
Mitochondrial Protein ◽  
Protein Carbonylation ◽  
Intermembrane Space ◽  
Flight Mass Spectrometry ◽  
Specific Proteins ◽  
Mitochondrial Intermembrane Space ◽  
Yeast Mutants

Saccharomyces cerevisiaeexpresses two forms of superoxide dismutase (SOD): MnSOD, encoded bySOD2, which is located within the mitochondrial matrix, and CuZnSOD, encoded bySOD1, which is located in both the cytosol and the mitochondrial intermembrane space. Because two different SOD enzymes are located in the mitochondrion, we examined the relative roles of each in protecting mitochondria against oxidative stress. Using protein carbonylation as a measure of oxidative stress, we have found no correlation between overall levels of respiration and the level of oxidative mitochondrial protein damage in either wild type orsodmutant strains. Moreover, mitochondrial protein carbonylation levels insod1,sod2, andsod1sod2mutants are not elevated in cells harvested from mid-logarithmic and early stationary phases, suggesting that neither MnSOD nor CuZnSOD is required for protecting the majority of mitochondrial proteins from oxidative damage during these early phases of growth. During late stationary phase, mitochondrial protein carbonylation increases in all strains, particularly insod1andsod1sod2mutants. By using matrix-assisted laser desorption ionization time-of-flight mass spectrometry, we have found that specific proteins become carbonylated insod1andsod2mutants. We identified six mitochondrial protein spots representing five unique proteins that become carbonylated in asod1mutant and 19 mitochondrial protein spots representing 11 unique proteins that become carbonylated in asod2mutant. Although some of the same proteins are carbonylated in both mutants, other proteins are not. These findings indicate that MnSOD and CuZnSOD have both unique and overlapping functions in the mitochondrion.

Conserved substrate binding by chaperones in the bacterial periplasm and the mitochondrial intermembrane space

2007 ◽  
Vol 409 (2) ◽  
pp. 377-387 ◽  
Author(s):  
Felicity H. Alcock ◽  
J. Günter Grossmann ◽  
Ian E. Gentle ◽  
Vladimir A. Likić ◽  
Trevor Lithgow ◽  
...  
Keyword(s):  
Substrate Binding ◽  
Binding Specificity ◽  
Yeast Cells ◽  
Mitochondrial Outer Membrane ◽  
Intermembrane Space ◽  
Hydrophobic Membrane ◽  
Inner Membrane ◽  
Mitochondrial Inner Membrane ◽  
Mitochondrial Intermembrane Space ◽  
Substrate Proteins

Mitochondria were derived from intracellular bacteria and the mitochondrial intermembrane space is topologically equivalent to the bacterial periplasm. Both compartments contain ATP-independent chaperones involved in the transport of hydrophobic membrane proteins. The mitochondrial TIM (translocase of the mitochondrial inner membrane) 10 complex and the periplasmic chaperone SurA were examined in terms of evolutionary relation, structural similarity, substrate binding specificity and their function in transporting polypeptides for insertion into membranes. The two chaperones are evolutionarily unrelated; structurally, they are also distinct both in their characteristics, as determined by SAXS (small-angle X-ray scattering), and in pairwise structural comparison using the distance matrix alignment (DALILite server). Despite their structural differences, SurA and the TIM10 complex share a common binding specificity in Pepscan assays of substrate proteins. Comprehensive analysis of the binding on a total of 1407 immobilized 13-mer peptides revealed that the TIM10 complex, like SurA, does not bind hydrophobic peptides generally, but that both chaperones display selectivity for peptides rich in aromatic residues and with net positive charge. This common binding specificity was not sufficient for SurA to completely replace TIM10 in yeast cells in vivo. In yeast cells lacking TIM10, when SurA is targeted to the intermembrane space of mitochondria, it binds translocating substrate proteins, but fails to completely transfer the substrate to the translocase in the mitochondrial inner membrane. We suggest that SurA was incapable of presenting substrates effectively to the primitive TOM (translocase of the mitochondrial outer membrane) and TIM complexes in early mitochondria, and was replaced by the more effective small Tim chaperone.

scholarly journals Armadillo repeat-containing protein 1 is a dual localization protein associated with mitochondrial intermembrane space bridging complex

2019 ◽  
Author(s):  
Fabienne Wagner ◽  
Tobias C. Kunz ◽  
Suvagata R. Chowdhury ◽  
Bernd Thiede ◽  
Martin Fraunholz ◽  
...  
Keyword(s):  
Intermembrane Space ◽  
Large Protein ◽  
Contact Site ◽  
Cellular Processes ◽  
Large Protein Complex ◽  
Dual Localization ◽  
Mammalian Mitochondria ◽  
Mitochondrial Distribution ◽  
Mitochondrial Intermembrane Space ◽  
Armadillo Repeat

AbstractCristae architecture is important for the function of mitochondria, the organelles that play the central role in many cellular processes. The mitochondrial contact site and cristae organizing system (MICOS) together with the sorting and assembly machinery (SAM) forms the mitochondrial intermembrane space bridging complex (MIB), a large protein complex present in mammalian mitochondria that partakes in the formation and maintenance of cristae. We report here a new subunit of the mammalian MICOS/MIB complex, an armadillo repeat-containing protein 1 (ArmC1). ArmC1 localizes both to cytosol and mitochondria, where it associates with the outer mitochondrial membrane through its carboxy-terminus. ArmC1 interacts with other constituents of the MICOS/MIB complex and its amounts are reduced upon MICOS/MIB complex depletion. Mitochondria lacking ArmC1 do not show defects in cristae structure, respiration or protein content, but appear fragmented and with reduced motility. ArmC1 represents therefore a peripheral MICOS/MIB component that appears to play a role in mitochondrial distribution in the cell.

scholarly journals Armadillo repeat-containing protein 1 is a dual localization protein associated with mitochondrial intermembrane space bridging complex

PLoS ONE ◽  
2019 ◽  
Vol 14 (10) ◽  
pp. e0218303 ◽  
Author(s):  
Fabienne Wagner ◽  
Tobias C. Kunz ◽  
Suvagata R. Chowdhury ◽  
Bernd Thiede ◽  
Martin Fraunholz ◽  
...  
Keyword(s):  
Intermembrane Space ◽  
Dual Localization ◽  
Mitochondrial Intermembrane Space ◽  
Armadillo Repeat
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