Elsevier

Mitochondrion

Volume 53, July 2020, Pages 109-120
Mitochondrion

Mitochondrial uncoupling protein-dependent signaling in plant bioenergetics and stress response

https://doi.org/10.1016/j.mito.2020.05.001Get rights and content
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Highlights

  • Plant UCPs biochemical properties, 3D structure, and physiological role are reviewed.

  • UCPs transcriptional regulation and co-expression networks across species is revisited.

  • Plant UCPs play a major role in cell signaling towards cellular bioenergetics and stress response.

Abstract

The biological function of plant mitochondrial uncoupling proteins (pUCPs) has been a matter of considerable controversy. For example, the pUCP capacity to uncouple respiration from ATP synthesis in vivo has never been fully acknowledged, in contrast to the mammalian UCP1 (mUCP1) role in uncoupling respiration-mediated thermogenesis. Interestingly, both pUCPs and mUCPs have been associated with stress response and metabolic perturbations. Some central questions that remain are how pUCPs and mUCPs compare in biochemical properties, molecular structure and cell biology under physiological and metabolically perturbed conditions. This review takes advantage of the large amount of data available for mUCPs to review the biochemical properties, 3D structure models and potential physiological roles of pUCPs during plant development and response to stress. The biochemical properties and structure of pUCPs are revisited in light of the recent findings that pUCPs catalyse the transport of metabolites across the mitochondrial inner membrane and the resolved mUCP2 protein structure. Additionally, transcriptional regulation and co-expression networks of UCP orthologues across species are analysed, taking advantage of publicly available curated experimental datasets. Taking these together, the biological roles of pUCPs are analysed in the context of their potential roles in thermogenesis, ROS production, cell signalling and the regulation of plant cellular bioenergetics. Finally, pUCPs biological function is discussed in the context of their potential role in protecting against environmental stresses.

Abbreviations

UCP
mitochondrial uncoupling protein
pUCP
plant UCP
mUCP
mammalian UCP
ROS
reactive oxygen species
BAT
brown adipose tissue
FA
fatty acids
GTP
guanosine triphosphate
OXPHOS
oxidative phosphorylation
ETC
electron transport chain
H
helix
P-kinks
proline kinks
DIC
dicarboxylate carrier
AOx
alternative oxidase
GO
gene ontology
ER
endoplasmic reticulum
ABA
abscisic acid
HNE
4-Hydroxynonenal
BSA
bovine serum albumin
C4
four-carbon

Keywords

Mitochondrial uncoupling proteins
Retrograde signalling
Plant bioenergetics
Thermogenesis
Stress response

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