Practice Questions

TLS Online TPP Program

#Question id: 12836

The final layer of control that is critical in the regulation of CDKs is a family of proteins known as CDK inhibitors, or CKIs, which bind directly to the cyclin-CDK complex and inhibit its activity. Which of the following function not done by CKIs?

#Unit 2. Cellular Organization

Binding of INK4s to CDK4 and CDK6 blocks their interaction with cyclin D and hence their protein kinase activity.
p27 prevents the premature activation of S phase CDKs during G1.
p21CIP plays an important role in the response of metazoan cells to DNA damage by inhibiting G1/S phase CDKs and S phase CDKs, and thereby blocking entry into or passage through S phase.
During ongoing DNA replication and in response to replication stress (slow DNA replication fork movement or DNA replication fork collapse), the ATR-Chk1 protein kinase cascade phosphorylates and inactivates Cdc25C, thereby preventing the activation of mitotic CDKs and inhibiting entry into mitosis.