Fumarate is a terminal electron acceptor in the mammalian electron transport chain.
Science
; 374(6572): 1227-1237, 2021 Dec 03.
Article
en En
| MEDLINE
| ID: mdl-34855504
ABSTRACT
For electrons to continuously enter and flow through the mitochondrial electron transport chain (ETC), they must ultimately land on a terminal electron acceptor (TEA), which is known to be oxygen in mammals. Paradoxically, we find that complex I and dihydroorotate dehydrogenase (DHODH) can still deposit electrons into the ETC when oxygen reduction is impeded. Cells lacking oxygen reduction accumulate ubiquinol, driving the succinate dehydrogenase (SDH) complex in reverse to enable electron deposition onto fumarate. Upon inhibition of oxygen reduction, fumarate reduction sustains DHODH and complex I activities. Mouse tissues display varying capacities to use fumarate as a TEA, most of which net reverse the SDH complex under hypoxia. Thus, we delineate a circuit of electron flow in the mammalian ETC that maintains mitochondrial functions under oxygen limitation.
Texto completo:
1
Bases de datos:
MEDLINE
Asunto principal:
Transporte de Electrón
/
Electrones
/
Fumaratos
Límite:
Animals
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Female
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Humans
Idioma:
En
Revista:
Science
Año:
2021
Tipo del documento:
Article
País de afiliación:
Estados Unidos