"the gene for the RA-degrading enzyme Cyp26a1 is mutated"

"Cyp26D1 expressed in 293T cells could metabolize all-trans RA, 9-cis RA, and 13-cis RA"

"expression of the RA-degrading enzyme cyp26a1 in the tailbud was controlled by Su(H) activity"

"metabolize RA into polar derivatives, function redundantly to shape RA-dependent gene-expression domains during hindbrain development"

"all-trans-13,14-dihydroretinol is transiently oxidized to all-trans-13,14-dihydroretinoic acid before being oxidized further by Cyp26 enzymes"

"The loss of the forebrain-specific RA-degrading enzyme cyp26a1 causes a forebrain phenotype that mimics tgif morphants"

"the RA-degrading Cyp26 enzymes play a critical role in defining the normal anterior limit of the pancreatic field"

"A reporter assay confirmed that cyp26a1 is a bona fide target of miR-19 in vivo"

"Cyp26a1, an enzyme that facilitates degradation of RA"

"Cyp26 enzymes largely act cell non-autonomously to promote appropriate cardiovascular development"

"posterior kidney progenitors are protected ventrally by the RA-catabolizing enzyme Cyp26a1"

"zebrafish embryos deficient for Cyp26a1 and Cyp26c1 enzymes, which promote RA degradation, have OFT defects"

"all-trans-RA is rapidly metabolized to more polar metabolites"

"A cytochrome P450 monooxygenase involved in the metabolism of all-trans retinoic acid"

"Zebrafish Cyp26a1 catalyzes oxidative metabolism of atRA, generating metabolites dominated by **4-hydroxy-RA (4-OH-RA)** and **4-oxo-RA (4-oxo-RA)** in microsome assays from transfected cells "

"Reviews of CYP26A1 metabolism emphasize **4-hydroxylation as the primary transformation** for CYP26A1 (and CYP26B1), with additional products such as **18-hydroxy-RA** and more polar secondary metabolites "

"Cell/microsome assays of zebrafish CYP26 family members show activity toward **RA isomers** (atRA, 9-cis RA, 13-cis RA) and **no detectable metabolism of retinol or retinal** under the tested conditions, supporting specialization for RA "

"CYP26 enzymes are described as **membrane-anchored microsomal (endoplasmic reticulum, ER) cytochrome P450s** with a heme center and class II P450 electron-transfer architecture: each catalytic cycle requires electrons supplied from **NADPH via cytochrome P450 oxidoreductase (POR)**, which uses **FAD and FMN** cofactors "

"A review summarizing CYP26 biochemical studies reports **high catalytic activity** for atRA, including **Km < 100 nM** (in COS-1 transfected cell systems) and **turnover ~1–10 pmol/min/pmol** "

"Hernandez et al. (2007; published Jan 2007; https://doi.org/10.1242/dev.02706) demonstrate that zebrafish orthologs of mammalian CYP26 genes (**cyp26a1, cyp26b1, cyp26c1**) act **redundantly** to shape the RA response pattern necessary for hindbrain development "

"cyp26a1 is expressed early in presumptive anterior neural ectoderm, and later in forebrain, midbrain, anterior hindbrain, and tailbud territories, contributing to establishment of anterior RA-depleted domains opposing posterior RA synthesis and shaping the rostrocaudal RA signaling landscape "

"cyp26a1 is under complex feedback and feedforward control by RA and Fgf signaling "

"microinjection of cyp26a1 mRNA reduces endogenous RA activity and yields phenotypes resembling reduced-RA conditions, consistent with a role in RA clearance "

"ER/microsomal cytochrome P450 enzyme that **hydroxylates/oxidizes retinoic acid**, producing **4-OH-RA and 4-oxo-RA** (major products), thereby reducing RA signaling capacity "