Figure 1. A short form of Mcl-1 is detected in the S and G2 phases of the cell cycle.

(A) Cytosolic and nuclear proteins were extracted from HL-60 cells that were sorted into G1, S and G2 stages of the cell cycle. Expression of Mcl-1 and Cdk1 was determined by immunoblotting. (B) Cytosolic and nuclear fractions from TF-1 and Jurkat cells were blotted for Mcl-1 as well as for actin, or histone H3 to define the purity of fractions. Results are representative of three independent experiments.