What would be likely to happen to cultured cells if you were

What would be likely to happen to cultured cells if you were able to treat them with an inhibitor that specifically depressed the activity of Cdk? Cdc25 phosphatase activity would be activated earlier than usual. The cells would remain in G_2 and would not move toward mitosis. Wee1 kinase activity would be turned off as well. The cells would be driven from G_2 to mitosis.

Solution

Cyclin-dependent kinases fall under the family of sugar kinases and have a major role in regulating the cell cycle. CDK is involved in regulation of the transcription process, mRNA processing, and differentiation of the nerve cells. When the CDK is inhibited the cells will be arrested.

The cells will remain in G2 phase because the activity of the Cdk enzyme is inhibited. Moreover, the wee1 kinase activity is turned on which will not allow the cells to enter into the mitosis phase and thereby arresting the cells in the G2 phase. Hence, option 2 is correct.

CDK is dependent on the Cdc25 phosphatase enzyme and activates the CDK enzyme by eliminating the phosphates from the residue in the CDK active sites. However, cdc25 phosphatase will not be activated earlier than usual as CDK depends on the cdc25 phosphatase enzyme. Hence, option 1 is incorrect.

Wee1 kinase activity inhibits the cells to enter the mitosis and also blocks the activity of the Cdk1. However, in this case, the CDK enzyme is inhibited and hence this will not affect the activity of the wee1 enzyme. Therefore, the Wee1 kinase should not be turned off. Hence, option 3 is incorrect.

The cells will not move to the mitosis phase as the Cdk enzyme is inhibited and wee1 kinase activity is present. this will not allow the cells to enter the mitosis phase. Hence, option 4 is incorrect.