The effect of biotin on cellular functions in HeLa cells.

HeLa cells cultured in a biotin-deficient medium show reduced rate of protein synthesis, DNA synthesis and growth. Addition of exogenous biotin to the cells cultured in biotin-deficient medium results in enhanced protein synthesis, DNA synthesis and cell growth. Continuous protein synthesis is required for the increase in DNA synthesis observed upon the addition of exogenous biotin to the cells cultured in biotin-deficient medium. These results suggest that cells cultured in biotin-deficient medium are arrested in the G1 stage of cell cycle and this block is removed upon the addition of biotin to the deficient medium.