Efficient Down-Regulation of Cyclin A-Associated Activity and Expression in Suspended Primary Keratinocytes

When suspended in methylcellulose, primary mouse keratinocytes cease proliferation and differentiate. Suspension also reduces the activity of the cyclindependent kinase cdk2, an important cell cycle regulatory enzyme. To determine how suspension modulates these events, we examined its effects on wild-type keratinocytes and keratinocytes nullizygous for the cdk2 inhibitor p21 Cip1 . After suspension of