In vivo binding of retinol to chromatin. The binding is mediated by a lipoprotein.
We have previously shown that exposure of responding cells to vitamin A leads to profound modifications of chromatin structure as revealed by an increased susceptibility to DNase I digestion, modified patterns of histone acetylation, and impaired synthesis of a nonhistone chromosomal protein (Ferrari, N., and Vidali, G. (1985) Eur. J. Biochem. 151, 305-310). The present results show that these effects are most probably due to the direct interaction between retinol and chromatin, and analysis of mononucleosomes and higher oligomers obtained from retinol-treated cells shows that retinol is indeed tightly bound to chromatin. Enzymatic digestions of vitamin A containing nucleosomes with proteinase K, phospholipase C, and phospholipase A2 support a model where the final binding of retinol to chromatin is mediated by a lipoprotein: the recognition of the binding sites on DNA being dictated by the proteic component while the hydrophobic retinol is solubilized in the fatty acid moiety.
Ferrari
N
N
Molecular Biology Laboratory, Istituto Nazionale per la Ricerca sul Cancro, Genova, Italy.
Pfeffer
U
U
Vidali
G
G
D002467:Cell Nucleus / Q000378:metabolism*; D002843:Chromatin / Q000378:metabolism*; D006367:HeLa Cells / Q000378:metabolism; D006801:Humans; D007700:Kinetics; D008074:Lipoproteins / Q000378:metabolism*; D019308:Palmitic Acid; D010169:Palmitic Acids / Q000378:metabolism; D014316:Tritium; D014801:Vitamin A / Q000378:metabolism*
D002843:Chromatin; D008074:Lipoproteins; D010169:Palmitic Acids; D014316:Tritium; D014801:Vitamin A; D019308:Palmitic Acid