Light-mediated retinoic acid production

摘要

Retinoids serve two main functions in boil- ogy: retinaldehyde forms the chromophore bound to opsins, and retinoic acid (RA) is the activating ligand of transcription factors. These two functions are linked in the vertebrate eye: we describe here that illumination of the retina results in an increase in RA synthesis, as detected with a RA bioassay and by HPLC. The synthesis is mediated by retinaldehyde dehy- drogenases which convert some of the chromophore all-trans retinaldehyde, released from bleached rhodopsin, into RA.