Inducible expression of exogenous CDK2, CDK4R24C, and CDK6R31C in MEL cell transfectants.

(A, B) The extracts were prepared from the indicated CDK-HA MEL cell transfectants cultured in the absence (−) or presence (+) of Dox for 36 hours. The levels of exogenous HA-tagged CDKs were determined by immunoblotting with anti-HA–specific antibody. (C, D) Extracts were prepared from the indicated CDK-HA MEL cell transfectants that had been cultured in the presence of Dox for 24 hours (0 time in the figure) followed by treatment with 5 mmol/L HMBA for the indicated times. The levels of exogenous HA-tagged CDKs were determined by immunoblotting as in panels A and B. The upper band in the 2 lower sections of panel C is CDK4R24C-HA, and the lower band is CDK2-HA. The upper band in the 2 lower sections of panel D is CDK6R31C-HA, and the lower band is CDK2-HA.