Anaerobic Mitochondria: Properties and Origins

Tielens, Aloysius G.M.; Hellemond, Jaap J. van

doi:10.1007/978-3-540-38502-8_5

Cited by 16 publications

(10 citation statements)

References 54 publications

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“…Depending on the metabolic state of the cell, the NADH pool might be subject to large fluctuations. The presence of alternative oxidases in anaerobic mitochondria provides a means for the cell to cope with such fluctuations in the NADH pool [ 29 ]. Such an alternative oxidase appears to be absent in N .…”

Section: Resultsmentioning

confidence: 99%

The [FeFe] hydrogenase of Nyctotherus ovalis has a chimeric origin

et al. 2007

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Background: The hydrogenosomes of the anaerobic ciliate Nyctotherus ovalis show how mitochondria can evolve into hydrogenosomes because they possess a mitochondrial genome and parts of an electrontransport chain on the one hand, and a hydrogenase on the other hand. The hydrogenase permits direct reoxidation of NADH because it consists of a [FeFe] hydrogenase module that is fused to two modules, which are homologous to the 24 kDa and the 51 kDa subunits of a mitochondrial complex I.

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Section: Resultsmentioning

confidence: 99%

The [FeFe] hydrogenase of Nyctotherus ovalis has a chimeric origin

et al. 2007

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“…Many eukaryotes can use their mitochondria for ATP synthesis and growth under aerobic or anaerobic conditions (Tielens et al 2002;Tielens and van Hellemond 2007;Müller et al 2012). Such organisms can be said to possess facultatively anaerobic mitochondria, which is the case for E. gracilis.…”

Section: Aerobic and Anaerobic Metabolic Pathwaysmentioning

confidence: 99%

The Mitochondrion of Euglena gracilis

Zimorski

Rauch

Hellemond

et al. 2017

Advances in Experimental Medicine and Biology

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In the presence of oxygen, Euglena gracilis mitochondria function much like mammalian mitochondria. Under anaerobiosis, E. gracilis mitochondria perform a malonyl-CoA independent synthesis of fatty acids leading to accumulation of wax esters, which serve as the sink for electrons stemming from glycolytic ATP synthesis and pyruvate oxidation. Some components (enzymes and cofactors) of Euglena's anaerobic energy metabolism are found among the anaerobic mitochondria of invertebrates, others are found among hydrogenosomes, the H-producing anaerobic mitochondria of protists.

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“…An estimate for the ATP yield per amino acid with mitochondria, but without O 2 , is more challenging because anaerobic mitochondria can use different pathways for ATP synthesis (19,175). For glucose, the ATP yields are well known.…”

Section: With Mitochondria Phagocytosis Has Energetic Benefitmentioning

confidence: 99%

The Physiology of Phagocytosis in the Context of Mitochondrial Origin

Martin

Tielens

Mentel

et al. 2017

Microbiol Mol Biol Rev

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103

132

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How mitochondria came to reside within the cytosol of their host has been debated for 50 years. Though current data indicate that the last eukaryote common ancestor possessed mitochondria and was a complex cell, whether mitochondria or complexity came first in eukaryotic evolution is still discussed. In autogenous models (complexity first), the origin of phagocytosis poses the limiting step at eukaryote origin, with mitochondria coming late as an undigested growth substrate. In symbiosis-based models (mitochondria first), the host was an archaeon, and the origin of mitochondria was the limiting step at eukaryote origin, with mitochondria providing bacterial genes, ATP synthesis on internalized bioenergetic membranes, and mitochondrion-derived vesicles as the seed of the eukaryote endomembrane system. Metagenomic studies are uncovering new host-related archaeal lineages that are reported as complex or phagocytosing, although images of such cells are lacking. Here we review the physiology and components of phagocytosis in eukaryotes, critically inspecting the concept of a phagotrophic host. From ATP supply and demand, a mitochondrion-lacking phagotrophic archaeal fermenter would have to ingest about 34 times its body weight in prokaryotic prey to obtain enough ATP to support one cell division. It would lack chemiosmotic ATP synthesis at the plasma membrane, because phagocytosis and chemiosmosis in the same membrane are incompatible. It would have lived from amino acid fermentations, because prokaryotes are mainly protein. Its ATP yield would have been impaired relative to typical archaeal amino acid fermentations, which involve chemiosmosis. In contrast, phagocytosis would have had great physiological benefit for a mitochondrion-bearing cell.

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Anaerobic Mitochondria: Properties and Origins

Cited by 16 publications

References 54 publications

The [FeFe] hydrogenase of Nyctotherus ovalis has a chimeric origin

The [FeFe] hydrogenase of Nyctotherus ovalis has a chimeric origin

The Mitochondrion of Euglena gracilis

The Physiology of Phagocytosis in the Context of Mitochondrial Origin

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