Retinol (vitamin A) is a precursor of retinal used in vision and retinoic acid involved in gene regulation. BCO1 generates two retinal molecules through oxidative cleavage of beta-carotene. Retinol is reversibly interconverted with retinal and can be stored as retinyl esters through LRAT-mediated esterification, while ester hydrolysis releases retinol. In the visual cycle, RPE65 converts all-trans-retinyl esters to 11-cis-retinol, which is oxidized to 11-cis-retinal by retinol dehydrogenases such as RDH5. Retinal dehydrogenases of the ALDH1A family oxidize retinal to retinoic acid. Retinoic acid undergoes CYP26-mediated hydroxylation, and 4-hydroxyretinoic acid can be glucuronidated by human UGT2B7.
Gene essentiality, reactions and expression in the selected subsystem
Explore how the genes of the selected subsystem vary across human cell types and cell type groups. The toggles switch between three views: whether each gene is predicted to be essential, non-essential or not present in each cell-type model, the number of reactions each gene is associated with in the selected subsystem of each model, and mRNA expression in each cell type or cell type group. Selecting a gene highlights its associated reactions in the subsystem map above. Some genes are predicted to be essential in all cell types, suggesting that they catalyse steps for which the model has no alternative route, whereas others are essential only in certain cell types or non-essential throughout, which may reflect alternative enzymes, isoforms or pathways that can compensate for their loss. Comparing the three views helps to show whether differences between cell types reflect differences in gene expression or in the metabolism of each cell type.
We use cookies to enhance the usability of our website. If you continue, we'll assume that you are happy to receive all cookies. More information. Don't show this again.