Studies on the mechanism of substrate induction and L-cyst(e)ine repression of alkaline phosphatase in mammalian cell cultures.

The mechanisms of substrate induction and L-cyst(e)ine repression of alkaline phosphatase were studied in tissue culture using an established African green monkey kidney cell line (BS-C-I). L-Cyst(e)ine repression and substrate induction are mutually antagonistic. Evidence is presented which suggests that the increase in alkaline phosphatase levels induced by monophosphate esters may in part be due to protection of the enzyme from cellular degradation, while L-cyst(e)ine is believed to act either by repressing the synthesis of the enzyme or by selectively increasing its catabolism.