Distinct Roles for Cyclin-Dependent Kinases in Cell Cycle Control

TLDR

Cdc2 is a key cell‑cycle regulator that belongs to the cyclin‑dependent kinase family in higher eukaryotes. The study sought to determine the specific roles of cyclin‑dependent kinases in human cell‑cycle progression. Dominant‑negative mutations were introduced to interrogate the function of these kinases. A dominant‑negative Cdc2 mutant arrested cells at the G2‑to‑M transition, while Cdk2 and Cdk3 mutants caused a G1 block, and the phenotypes were rescued by the corresponding wild‑type kinases, demonstrating that Cdk3, alongside Cdc2 and Cdk2, executes a distinct essential function in the mammalian cell cycle.

Abstract

The key cell-cycle regulator Cdc2 belongs to a family of cyclin-dependent kinases in higher eukaryotes. Dominant-negative mutations were used to address the requirement for kinases of this family in progression through the human cell cycle. A dominant-negative Cdc2 mutant arrested cells at the G 2 to M phase transition, whereas mutants of the cyclin-dependent kinases Cdk2 and Cdk3 caused a G 1 block. The mutant phenotypes were specifically rescued by the corresponding wild-type kinases. These data reveal that Cdk3, in addition to Cdc2 and Cdk2, executes a distinct and essential function in the mammalian cell cycle.