Indicate whether each of the following descriptions better applies to a Wee1 protein (W) or a Cdc25 protein (C). Your answer would be a four-letter string composed of letters W and C only, e.g. WWCW.
( ) It is a protein kinase.
( ) It activates M-Cdk complexes.
( ) It is activated by M-Cdk complexes.
( ) Its loss in fission yeast results in small cell size.

Question

Indicate whether each of the following descriptions better applies to a Wee1 protein (W) or a Cdc25 protein (C). Your answer would be a four-letter string composed of letters W and C only, e.g. WWCW.
( )	It is a protein kinase.
( )	It activates M-Cdk complexes.
( )	It is activated by M-Cdk complexes.
( )	Its loss in fission yeast results in small cell size.

Quizplus · Accepted Answer

Wee1 kinases phosphorylate and inactivate cyclin-Cdk complexes; Cdc25 phosphatases do the opposite. In a positive feedback loop at the onset of mitosis, M-Cdk inactivates its inactivator, Wee1, and activates its activator, a Cdc25. The small cell size in wee mutants can result from Wee1 depletion.

Indicate Whether Each of the Following Descriptions Better Applies to a Wee1