scholarly journals Significance of AtMTM1 and AtMTM2 for Mitochondrial MnSOD Activation in Arabidopsis

2021 ◽  
Vol 12 ◽  
Author(s):  
Shu-Hsuan Hu ◽  
Shu-Fan Lin ◽  
Ya-Chen Huang ◽  
Chien-Hsun Huang ◽  
Wen-Yu Kuo ◽  
...  
Keyword(s):  
Transient Expression ◽  
Methyl Viologen ◽  
Ion Homeostasis ◽  
Activation Mechanism ◽  
Mitochondrial Carrier ◽  
Evolutionarily Conserved ◽  
Mitochondrial Carrier Family ◽  
Fe Homeostasis ◽  
Mutant Cells ◽  
Mnsod Activity

The manganese (Mn) tracking factor for mitochondrial Mn superoxide dismutase (MnSOD) has been annotated as yMTM1 in yeast, which belongs to the mitochondrial carrier family. We confirmed that Arabidopsis AtMTM1 and AtMTM2 are functional homologs of yMYM1 as they can revive yeast MnSOD activity in yMTM1-mutant cells. Transient expression of AtMnSOD-3xFLAG in the AtMTM1 and AtMTM2-double mutant protoplasts confirmed that AtMTM1 and AtMTM2 are required for AtMnSOD activation. Our study revealed that AtMnSOD interacts with AtMTM1 and AtMTM2 in the mitochondria. The expression levels of AtMTM1, AtMTM2, and AtMnSOD respond positively to methyl viologen (MV) and metal stress. AtMTM1 and AtMTM2 are involved in Mn and Fe homeostasis, root length, and flowering time. Transient expression of chloroplast-destined AtMnSOD revealed that an evolutionarily conserved activation mechanism, like the chloroplastic-localized MnSOD in some algae, still exists in Arabidopsis chloroplasts. This study strengthens the proposition that AtMTM1 and AtMTM2 participate in the AtMnSOD activation and ion homeostasis.

scholarly journals Antioxidant Synergy of Mitochondrial Phospholipase PNPLA8/iPLA2γ with Fatty Acid–Conducting SLC25 Gene Family Transporters

Antioxidants ◽  
2021 ◽  
Vol 10 (5) ◽  
pp. 678
Author(s):  
Martin Jabůrek ◽  
Pavla Průchová ◽  
Blanka Holendová ◽  
Alexander Galkin ◽  
Petr Ježek
Keyword(s):  
Lipid Peroxidation ◽  
Unsaturated Fatty Acids ◽  
Second Messengers ◽  
Redox Status ◽  
Mitochondrial Uncoupling ◽  
Mitochondrial Carrier ◽  
Mitochondrial Superoxide ◽  
Redox Activation ◽  
Mitochondrial Carrier Family ◽  
Alternatively Activated

Patatin-like phospholipase domain-containing protein PNPLA8, also termed Ca2+-independent phospholipase A2γ (iPLA2γ), is addressed to the mitochondrial matrix (or peroxisomes), where it may manifest its unique activity to cleave phospholipid side-chains from both sn-1 and sn-2 positions, consequently releasing either saturated or unsaturated fatty acids (FAs), including oxidized FAs. Moreover, iPLA2γ is directly stimulated by H2O2 and, hence, is activated by redox signaling or oxidative stress. This redox activation permits the antioxidant synergy with mitochondrial uncoupling proteins (UCPs) or other SLC25 mitochondrial carrier family members by FA-mediated protonophoretic activity, termed mild uncoupling, that leads to diminishing of mitochondrial superoxide formation. This mechanism allows for the maintenance of the steady-state redox status of the cell. Besides the antioxidant role, we review the relations of iPLA2γ to lipid peroxidation since iPLA2γ is alternatively activated by cardiolipin hydroperoxides and hypothetically by structural alterations of lipid bilayer due to lipid peroxidation. Other iPLA2γ roles include the remodeling of mitochondrial (or peroxisomal) membranes and the generation of specific lipid second messengers. Thus, for example, during FA β-oxidation in pancreatic β-cells, H2O2-activated iPLA2γ supplies the GPR40 metabotropic FA receptor to amplify FA-stimulated insulin secretion. Cytoprotective roles of iPLA2γ in the heart and brain are also discussed.

Thermoregulation: What Role for UCPs in Mammals and Birds?

2005 ◽  
Vol 25 (3-4) ◽  
pp. 227-249 ◽  
Author(s):  
Julien Mozo ◽  
Yalin Emre ◽  
Frederic Bouillaud ◽  
Daniel Ricquier ◽  
Francois Criscuolo
Keyword(s):  
Adipose Tissue ◽  
Heat Generation ◽  
Cold Exposure ◽  
Mitochondrial Respiration ◽  
Physiological Function ◽  
Mitochondrial Carrier ◽  
Brown Adipose ◽  
Mitochondrial Carrier Family ◽  
Cell Energy ◽  
Avian Ucp

Mammals and birds are endotherms and respond to cold exposure by the means of regulatory thermogenesis, either shivering or non-shivering. In this latter case, waste of cell energy as heat can be achieved by uncoupling of mitochondrial respiration. Uncoupling proteins, which belong to the mitochondrial carrier family, are able to transport protons and thus may assume a thermogenic function. The mammalian UCP1 physiological function is now well understood and gives to the brown adipose tissue the capacity for heat generation. But is it really the case for its more recently discovered isoforms UCP2 and UCP3? Additionally, whereas more and more evidence suggests that non-shivering also exists in birds, is the avian UCP also involved in response to cold exposure? In this review, we consider the latest advances in the field of UCP biology and present putative functions for UCP1 homologues.

scholarly journals Presence of a Member of the Mitochondrial Carrier Family in Hydrogenosomes: Conservation of Membrane-Targeting Pathways between Hydrogenosomes and Mitochondria

2000 ◽  
Vol 20 (7) ◽  
pp. 2488-2497 ◽  
Author(s):  
Sabrina D. Dyall ◽  
Carla M. Koehler ◽  
Maria G. Delgadillo-Correa ◽  
Peter J. Bradley ◽  
Evelyn Plümper ◽  
...  
Keyword(s):  
Trichomonas Vaginalis ◽  
Protein Targeting ◽  
Phylogenetic Analyses ◽  
Eukaryotic Cell ◽  
Membrane Targeting ◽  
Carrier Proteins ◽  
Mitochondrial Carrier ◽  
Mitochondrial Carrier Family ◽  
Targeting Signal ◽  
Mitochondrial Carrier Proteins

ABSTRACT A number of microaerophilic eukaryotes lack mitochondria but possess another organelle involved in energy metabolism, the hydrogenosome. Limited phylogenetic analyses of nuclear genes support a common origin for these two organelles. We have identified a protein of the mitochondrial carrier family in the hydrogenosome ofTrichomonas vaginalis and have shown that this protein, Hmp31, is phylogenetically related to the mitochondrial ADP-ATP carrier (AAC). We demonstrate that the hydrogenosomal AAC can be targeted to the inner membrane of mitochondria isolated from Saccharomyces cerevisiae through the Tim9-Tim10 import pathway used for the assembly of mitochondrial carrier proteins. Conversely, yeast mitochondrial AAC can be targeted into the membranes of hydrogenosomes. The hydrogenosomal AAC contains a cleavable, N-terminal presequence; however, this sequence is not necessary for targeting the protein to the organelle. These data indicate that the membrane-targeting signal(s) for hydrogenosomal AAC is internal, similar to that found for mitochondrial carrier proteins. Our findings indicate that the membrane carriers and membrane protein-targeting machinery of hydrogenosomes and mitochondria have a common evolutionary origin. Together, they provide strong evidence that a single endosymbiont evolved into a progenitor organelle in early eukaryotic cells that ultimately give rise to these two distinct organelles and support the hydrogen hypothesis for the origin of the eukaryotic cell.

Computational studies of the mitochondrial carrier family SLC25. Present status and future perspectives

2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Andrea Pasquadibisceglie ◽  
Fabio Polticelli
Keyword(s):  
Transport Mechanism ◽  
Experimental Studies ◽  
Intermembrane Space ◽  
Mitochondrial Carrier ◽  
Mitochondrial Homeostasis ◽  
The Matrix ◽  
Mitochondrial Carrier Family ◽  
Mitochondrial Intermembrane Space ◽  
Computational Analyses

Abstract The members of the mitochondrial carrier family, also known as solute carrier family 25 (SLC25), are transmembrane proteins involved in the translocation of a plethora of small molecules between the mitochondrial intermembrane space and the matrix. These transporters are characterized by three homologous domains structure and a transport mechanism that involves the transition between different conformations. Mutations in regions critical for these transporters’ function often cause several diseases, given the crucial role of these proteins in the mitochondrial homeostasis. Experimental studies can be problematic in the case of membrane proteins, in particular concerning the characterization of the structure–function relationships. For this reason, computational methods are often applied in order to develop new hypotheses or to support/explain experimental evidence. Here the computational analyses carried out on the SLC25 members are reviewed, describing the main techniques used and the outcome in terms of improved knowledge of the transport mechanism. Potential future applications on this protein family of more recent and advanced in silico methods are also suggested.

scholarly journals Activation of an Essential Calcium Signaling Pathway in Saccharomyces cerevisiae by Kch1 and Kch2, Putative Low-Affinity Potassium Transporters

2012 ◽  
Vol 12 (2) ◽  
pp. 204-214 ◽  
Author(s):  
Christopher P. Stefan ◽  
Nannan Zhang ◽  
Takaaki Sokabe ◽  
Alberto Rivetta ◽  
Clifford L. Slayman ◽  
...  
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Animal Cell ◽  
Cell Types ◽  
Activation Mechanism ◽  
Homologous Pair ◽  
Content Type ◽  
Mating Pheromones ◽  
Inwardly Rectifying ◽  
Low K ◽  
Mutant Cells

ABSTRACT In the budding yeast Saccharomyces cerevisiae , mating pheromones activate a high-affinity Ca 2+ influx system (HACS) that activates calcineurin and is essential for cell survival. Here we identify extracellular K + and a homologous pair of transmembrane proteins, Kch1 and Kch2 (Prm6), as necessary components of the HACS activation mechanism. Expression of Kch1 and especially Kch2 was strongly induced during the response to mating pheromones. When forcibly overexpressed, Kch1 and Kch2 localized to the plasma membrane and activated HACS in a fashion that depended on extracellular K + but not pheromones. They also promoted growth of trk1 trk2 mutant cells in low K + environments, suggesting they promote K + uptake. Voltage-clamp recordings of protoplasts revealed diminished inward K + currents in kch1 kch2 double-mutant cells relative to the wild type. Conversely, heterologous expression of Kch1 in HEK293T cells caused the appearance of inwardly rectifying K + currents. Collectively, these findings suggest that Kch1 and Kch2 directly promote K + influx and that HACS may electrochemically respond to K + influx in much the same way as the homologous voltage-gated Ca 2+ channels in most animal cell types.

Expansion of the mitochondrial carrier family

1993 ◽  
Vol 144 (8) ◽  
pp. 671-672 ◽  
Author(s):  
J. Kuan ◽  
M.H. Saier
Keyword(s):  
Mitochondrial Carrier ◽  
Mitochondrial Carrier Family

scholarly journals Identification of the mitochondrial pyruvate carrier in Saccharomyces cerevisiae

2003 ◽  
Vol 374 (3) ◽  
pp. 607-611 ◽  
Author(s):  
John C. W. HILDYARD ◽  
Andrew P. HALESTRAP
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Deletion Mutant ◽  
Homologous Proteins ◽  
Mitochondrial Carrier ◽  
Mitochondrial Pyruvate Carrier ◽  
Mitochondrial Carrier Family ◽  
Human And Mouse

Mitochondrial pyruvate transport is fundamental for metabolism and mediated by a specific inhibitable carrier. We have identified the yeast mitochondrial pyruvate carrier by measuring inhibitor-sensitive pyruvate uptake into mitochondria from 18 different Saccharomyces cerevisiae mutants, each lacking an unattributed member of the mitochondrial carrier family (MCF). Only mitochondria from the YIL006w deletion mutant exhibited no inhibitor-sensitive pyruvate transport, but otherwise behaved normally. YIL006w encodes a 41.9 kDa MCF member with homologous proteins present in both the human and mouse genomes.

Phylogenetic Classification of the Mitochondrial Carrier Family ofSaccharomyces cerevisiae

Yeast ◽  
1997 ◽  
Vol 13 (6) ◽  
pp. 573-581 ◽  
Author(s):  
BENAISSA EL MOUALIJ ◽  
CLAIRE DUYCKAERTS ◽  
JOSETTE LAMOTTE-BRASSEUR ◽  
FRANCIS E. SLUSE
Keyword(s):  
Mitochondrial Carrier ◽  
Phylogenetic Classification ◽  
Mitochondrial Carrier Family
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