試題詳解

26. Which of the following statements concerning cyclins is not correct?
(A) They catalyze the phosphorylation of cyclin-dependent protein kinases.
(B) They are regulatory subunits for enzymes that catalyze the phosphorylation of proteins.
(C) They are activated and degraded during the cell cycle.
(D) They can become linked to ubiquitin.
(E) They contain specific amino acid sequences that target them for proteolysis.