End of the line: proteolytic degradation of cyclin-dependent kinase inhibitors Review Article

Cyclin-dependent kinase inhibitors (CKIs) are crucial regulators of cell-cycle progression. The CKI Sic1 controls the timing of DNA replication by inhibiting Clb-Cdc28 kinase. Phosphorylation of Sic1t by Cln-Cdc28 kinase alleviates this inhibition by targeting Sic1 for degradation through the ubiquitin-mediated proteolytic pathway.