Calcium oscillations optimize the energetic efficiency of mitochondrial metabolism.
iScience
; 27(3): 109078, 2024 Mar 15.
Article
in En
| MEDLINE
| ID: mdl-38375217
ABSTRACT
Energy transduction is central to living organisms, but the impact of enzyme regulation and signaling on its thermodynamic efficiency is generally overlooked. Here, we analyze the efficiency of ATP production by the tricarboxylic acid cycle and oxidative phosphorylation, which generate most of the chemical energy in eukaryotes. Calcium signaling regulates this pathway and can affect its energetic output, but the concrete energetic impact of this cross-talk remains elusive. Calcium enhances ATP production by activating key enzymes of the tricarboxylic acid cycle while calcium homeostasis is ATP-dependent. We propose a detailed kinetic model describing the calcium-mitochondria cross-talk and analyze it using nonequilibrium thermodynamics after identifying the effective reactions driving mitochondrial metabolism out of equilibrium, we quantify the mitochondrial thermodynamic efficiency for different conditions. Calcium oscillations, triggered by extracellular stimulation or energy deficiency, boost the thermodynamic efficiency of mitochondrial metabolism, suggesting a compensatory role of calcium signaling in mitochondrial bioenergetics.
Full text:
1
Collection:
01-internacional
Database:
MEDLINE
Language:
En
Journal:
IScience
Year:
2024
Document type:
Article
Affiliation country:
Luxemburgo
Country of publication:
Estados Unidos