Increase in cell-surface N-acetylglucosaminide β(1→4)galactosyltransferase activity with retinoic acid-induced differentiation of F₉ embryonal carcinoma cells

Exposure of F₉ cells to all-trans-retinoic acid over a period of 6 days resulted in 4-fold induction of cell surface N-acetylglucosaminide β(1→4)galactosyltransferase (GT) activity. The retinoic acid-induced GT activity was further enhanced by treatment of the cells with 8-bromo cyclic AMP. The ability of retinoic acid alone, or retinoic acid in combination with 8-bromo cyclic AMP, to induce GT activity was inhibited by both actinomycin D and cycloheximide. These findings indicate that the induction of galactosyltransferase activity noted with differentiation of F₉ cells involves de novo synthesis of new enzyme protein.