Mitochondrial cristae remodeling: Mechanisms, functions, and pathology

ABSTRACT Mitochondrial cristae are the principal sites of oxidative phosphorylation and are central to mitochondria-dependent energy metabolism. Rather than static folds, cristae are dynamic bioenergetic compartments that remodel in response to physiological and stress cues. During remodeling, their number, length, width, lateral alignment, curvature/stiffness, and the geometry of crista junctions (CJs) can change. Depending on cellular context, cristae may increase in abundance, tighten or widen, and exhibit opening or closure of CJs, with corresponding effects on respiratory-chain organization and supercomplex assembly. Key regulators include OPA1 (and its proteolytic processing), the MICOS complex that scaffolds CJs, F1Fo-ATP synthase dimerization/oligomerization that shapes high-curvature ridges, and cardiolipin, which stabilizes inner-membrane architecture. Abnormal cristae compromise electron transport, ATP production, and mitochondrial metabolism, contributing to neurodegeneration and metabolic disease etc. In this review, we synthesize current insights into the molecular control of cristae ultrastructure and its impact on mitochondrial metabolism, delineate structural features and quantitative readouts, and highlight mechanisms that govern cristae remodeling under physiological and stress conditions, with an emphasis on diseases arising from aberrant crista architecture.