Effects of retinol on chromatin structure.

The effect of retinol is studied in 3T3 cultured cells. The vitamin induces a decreased rate of cell proliferation and an augmented sensitivity of chromatin to DNase I digestion. Biochemical analyses of chromosomal components establish that the rates of radioactive acetate uptake and turnover on histones are increased leaving unaltered the steady-state level of histone acetylation. The presence of retinol in the culture medium also causes the disappearance of a protein of Mr 20 000, which is co-extracted with the high-mobility-group proteins. The observed changes in chromatin structure and composition are reversible when retinol is removed from the culture medium.