| First Author | Brodeur H | Year | 2003 |
| Journal | J Lipid Res | Volume | 44 |
| Issue | 2 | Pages | 303-13 |
| PubMed ID | 12576512 | Mgi Jnum | J:82059 |
| Mgi Id | MGI:2450793 | Doi | 10.1194/jlr.M200359-JLR200 |
| Citation | Brodeur H, et al. (2003) Cloning of monkey RALDH1 and characterization of retinoid metabolism in monkey kidney proximal tubule cells. J Lipid Res 44(2):303-13 |
| abstractText | All-trans and 9-cis retinoic acids function as ligands for retinoic acid receptors (RARs and RXRs), which are ligand-dependent transcription factors and play important roles in development and cellular differentiation. Several retinal dehydrogenases are likely to contribute to the production of all-trans and 9-cis RAs in vivo, but their respective roles in different tissues are still poorly characterized. We have previously characterized and cloned from kidney tissues the rat retinal dehydrogenase type 1 (RALDH1), which oxidizes all-trans and 9-cis retinal with high efficiency but is inactive with 13-cis retinal. Here we have characterized the retinal-oxidizing activity in monkey JTC12 cells, which are derived from kidney proximal tubules. In vitro assay of cell lysates revealed the presence of a NAD+-dependent dehydrogenase that catalyzed the oxidation of all-trans, 9-cis, and 13-cis retinal. Northern blot analysis of JTC12 RNAs and cloning by reverse transcription-polymerase chain reaction demonstrated expression of a monkey homolog of RALDH1. Bacterially expressed JTC12 RALDH1 catalyzed conversion of all three retinal isomers, with a higher catalytic efficiency for 9-cis retinal than for all-trans and 13-cis retinal. Accordingly, live JTC12 produced 9-cis retinoic acid more efficiently than all-trans retinoic acid from their respective retinal precursors. Only metabolites corresponding to the same steric conformation were formed from 9-cis or all-trans retinal, indicating a lack of detectable isomerizing activity in JTC12 cells. |
