Structural bias in vitamin A metabolism: Why α-retinoids miss the eye.

ABSTRACT: Provitamin A carotenoids are metabolized to retinoids, critical for vision and transcriptional regulation, through oxidative cleavage by carotenoid oxygenases. β-Carotene, a symmetric carotenoid, undergoes central cleavage by β-carotene oxygenase 1 (BCO1), generating two molecules of retinaldehyde. In contrast, the metabolism of asymmetric carotenoids, such as α-carotene (β,ε-carotene) and β-cryptoxanthin (β,β-carotene-3-ol), produces noncanonical apocarotenoid derivatives in addition to retinaldehyde. Here, we dissect the enzymatic pathways and transport mechanisms governing these metabolic fates in mice. We demonstrate that α-carotene is cleaved exclusively by BCO1 to yield retinaldehyde and α-retinaldehyde, bypassing mitochondrial processing. β-Cryptoxanthin, however, undergoes an initi

SUBMITTER: Bandara S 

PROVIDER: S-EPMC12550161 | biostudies-literature | 2025 Oct

REPOSITORIES: biostudies-literature