Retinol bound to cellular retinol-binding protein is a substrate for cytosolic retinoic acid synthesis.

Cellular Retinol- and Retinoic Acid-binding Proteins of Bovine Retina

A three-step purification has been developed for the cellular retinoland cellular retinoic acid-binding proteins from extracts of bovine retina. The two binding proteins elute together in Step 1 (gel filtration) and separate in Step 2 (DEAE-cellulose chromatography), and each is purified to apparent homogeneity in the third step (calcium phosphate gel chromatography). The retinoland retinoic ac...

Uptake of retinol and retinoic acid from serum retinol-binding protein by retinal pigment epithelial cells.

Isolated pigment epithelial cells from bovine eyes were shown to be capable of taking up retinol and retinoic acid. The uptake was dependent on the ligands being presented to the cells as complexes with serum retinol-binding protein. Neither free retinol nor retinol or retinoic acid presented as serum albumin complexes were taken up by the pigment epithelial cells. The transport of retinal and ...

Mutations in the gene encoding retinol binding protein and retinol deficiency: is there compensation by retinyl esters and retinoic acid?

Effects of dietary retinoic acid on cellular retinol- and retinoic acid-binding protein levels in various rat tissues.

A study was conducted to explore the effects of retinoic acid, fed to retinol-deficient rats, on the tissue distribution and levels of cellular retinol-binding protein (CRBP) and cellular retinoic acid-binding protein (CRABP). Sensitive and specific radioimmunoassays were employed to measure the levels of both CRBP and CRABP. Two groups of six male rats each were fed a purified retinoid-deficie...

Acyl-CoA-independent esterification of retinol bound to cellular retinol-binding protein (type II) by microsomes from rat small intestine.

Cellular retinol-binding protein (type II) (CRBP(II)), a newly described retinol-binding protein, is present in the small intestinal absorptive cell at high levels. Retinol (vitamin A alcohol) presented as a complex with CRBP(II) was found here to be esterified by microsomal preparations from rat small intestinal mucosa. The esterification observed utilized an endogenous acyl donor(s) and produ...