Distribution of 11-cis LRAT, 11-cis RD and 11-cis REH in bovine retinal pigment epithelium membranes

Biochim Biophys Acta. 1998 Oct 2;1394(1):16-22. doi: 10.1016/s0005-2760(98)00078-2.


Our recent finding of the co-localization of 11-cis retinyl esters and 11-cis retinyl ester hydrolase (11-cis REH) activity in bovine retinal pigment epithelium (RPE) plasma membrane (PM) has led us to explore the possibility that the PM may provide 11-cis retinal for rhodopsin regeneration. In the RPE, visual chromophore is synthesized via a membrane associated 11-cis retinol dehydrogenase (11-cis RD). Accordingly, bovine RPE membranes enriched with either endoplasmic reticulum (ER) or plasma membrane (PM) enzyme markers were prepared and assayed for visual cycle enzyme activities. Pronounced 11-cis RD activity was associated with both ER- and PM-enriched membrane fractions. In contrast, 11-cis REH activity was mostly recovered in PM-enriched fractions while LRAT activity was found only in ER-enriched membranes. The finding that both 11-cis retinol and 11-cis retinal can be produced at the PM of the bovine RPE strongly suggests that 11-cis retinyl esters at this subcellular locale serve as a precursor of visual chromophore for pigment regeneration.

Publication types

  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Alcohol Oxidoreductases / metabolism*
  • Animals
  • Carboxylic Ester Hydrolases / metabolism*
  • Cattle
  • Pigment Epithelium of Eye / enzymology*
  • Pigment Epithelium of Eye / ultrastructure
  • Retinaldehyde / metabolism
  • Vitamin A / metabolism*


  • Vitamin A
  • Alcohol Oxidoreductases
  • retinol dehydrogenase
  • Carboxylic Ester Hydrolases
  • retinyl esterase
  • Retinaldehyde