scholarly journals Mitochondrial Phospholipid Homeostasis Is Regulated by the i-AAA Protease PaIAP and Affects Organismic Aging

Cells ◽  
2021 ◽  
Vol 10 (10) ◽  
pp. 2775
Author(s):  
Timo Löser ◽  
Aljoscha Joppe ◽  
Andrea Hamann ◽  
Heinz D. Osiewacz

Mitochondria are ubiquitous organelles of eukaryotic organisms with a number of essential functions, including synthesis of iron-sulfur clusters, amino acids, lipids, and adenosine triphosphate (ATP). During aging of the fungal aging model Podospora anserina, the inner mitochondrial membrane (IMM) undergoes prominent morphological alterations, ultimately resulting in functional impairments. Since phospholipids (PLs) are key components of biological membranes, maintenance of membrane plasticity and integrity via regulation of PL biosynthesis is indispensable. Here, we report results from a lipidomic analysis of isolated mitochondria from P. anserina that revealed an age-related reorganization of the mitochondrial PL profile and the involvement of the i-AAA protease PaIAP in proteolytic regulation of PL metabolism. The absence of PaIAP enhances biosynthesis of characteristic mitochondrial PLs, leads to significant alterations in the acyl composition of the mitochondrial signature PL cardiolipin (CL), and induces mitophagy. These alterations presumably cause the lifespan increase of the PaIap deletion mutant under standard growth conditions. However, PaIAP is required at elevated temperatures and for degradation of superfluous CL synthase PaCRD1 during glycolytic growth. Overall, our study uncovers a prominent role of PaIAP in the regulation of PL homeostasis in order to adapt membrane plasticity to fluctuating environmental conditions as they occur in nature.

1997 ◽  
Vol 69 (3) ◽  
pp. 183-195 ◽  
Author(s):  
A. G. NIKITIN ◽  
R. J. SHMOOKLER REIS

Genetic instability is associated with aging in many species. One of the initiating factors for genetic instability is the movement of transposable elements (TEs), which occur in all prokaryotic and eukaryotic organisms. The hypothesis that TEs could be involved in the aging process is discussed and the correlation between aging and activity of TEs is analysed in a variety of biological systems.


Author(s):  
Alisha G. Lewis ◽  
Robert Caldwell ◽  
Jason V. Rogers ◽  
Maria Ingaramo ◽  
Rebecca Y. Wang ◽  
...  

The electron transport chain (ETC) is a well-studied and highly conserved metabolic pathway that produces ATP through generation of a proton gradient across the inner mitochondrial membrane coupled to oxidative phosphorylation. ETC mutations are associated with a wide array of human disease conditions and to aging-related phenotypes in a number of different organisms. In this study, we sought to better understand the role of the ETC in aging using a yeast model. A panel of ETC mutant strains that fail to survive starvation was used to isolate suppressor mutants that survive. These suppressors tend to fall into major nutrient sensing and signaling pathways, suggesting that the ETC is involved in proper starvation signaling to these pathways in yeast. These suppressors also partially restore ETC-associated gene expression and pH homeostasis defects, though it remains unclear if these phenotypes directly cause the suppression or are simply effects. This work further highlights the complex cellular network connections between metabolic pathways and signaling events in the cell, and their potential roles in aging and age-related diseases.


Metallomics ◽  
2021 ◽  
Author(s):  
Stephen A Pearson ◽  
J A Cowan

Abstract Glutathione is the major thiol-containing species in both prokaryotes and eukaryotes and plays a wide variety of roles, including detoxification of metals by sequestration, reduction, and efflux. ABC transporters such as MRP1 and MRP2 detoxify the cell from certain metals by exporting the cations as a metal-glutathione complex. The ability of the bacterial Atm1 protein to efflux metal-glutathione complexes appears to have evolved over time to become the ABCB7 transporter in mammals, located in the inner mitochondrial membrane. No longer needed for the role of cellular detoxification, ABCB7 appears to be used to transport glutathione-coordinated iron-sulfur clusters from mitochondria to the cytosol.


Author(s):  
B.J. Panessa-Warren ◽  
G.T. Tortora ◽  
J.B. Warren

Some bacteria are capable of forming highly resistant spores when environmental conditions are not adequate for growth. Depending on the genus and species of the bacterium, these endospores are resistant in varying degrees to heat, cold, pressure, enzymatic degradation, ionizing radiation, chemical sterilants,physical trauma and organic solvents. The genus Clostridium, responsible for botulism poisoning, tetanus, gas gangrene and diarrhea in man, produces endospores which are highly resistant. Although some sporocides can kill Clostridial spores, the spores require extended contact with a sporocidal agent to achieve spore death. In most clinical situations, this extended period of treatment is not possible nor practical. This investigation examines Clostridium sporogenes endospores by light, transmission and scanning electron microscopy under various dormant and growth conditions, cataloging each stage in the germination and outgrowth process, and analyzing the role played by the exosporial membrane in the attachment and germination of the spore.


2010 ◽  
Author(s):  
Charlotte Froger ◽  
Badiaa Bouazzaoui ◽  
Laurence Taconnat

2020 ◽  
Vol 17 ◽  
Author(s):  
Christina Karakosta ◽  
Argyrios Tzamalis ◽  
Michalis Aivaliotis ◽  
Ioannis Tsinopoulos

Background/Objective:: The aim of this systematic review is to identify all the available data on human lens proteomics with a critical role to age-related cataract formation in order to elucidate the physiopathology of the aging lens. Materials and Methods:: We searched on Medline and Cochrane databases. The search generated 328 manuscripts. We included nine original proteomic studies that investigated human cataractous lenses. Results:: Deamidation was the major age-related post-translational modification. There was a significant increase in the amount of αA-crystallin D-isoAsp58 present at all ages, while an increase in the extent of Trp oxidation was apparent in cataract lenses when compared to aged normal lenses. During aging, enzymes with oxidized cysteine at critical sites included GAPDH, glutathione synthase, aldehyde dehydrogenase, sorbitol dehydrogenase, and PARK7. Conclusion:: D-isoAsp in αA crystallin could be associated with the development of age-related cataract in human, by contributing to the denaturation of a crystallin, and decreasing its ability to act as a chaperone. Oxidation of Trp may be associated with nuclear cataract formation in human, while the role of oxidant stress in age-related cataract formation is dominant.


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