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Updated: Aug 12, 2026

Assaying Proteasomal Degradation in a Cell-free System in Plants
Published on: March 26, 2014
Ubiquitin-mediated proteolysis of vertebrate G1- and S-phase regulators
1Department of Molecular Medicine, Institute of Biotechnology, University of Texas Health Science Center at San Antonio, 15355 Lambda Drive, San Antonio, TX 78245-3207, USA. yew@uthscsa.edu
Abstract:
Cell-cycle progression in all eukaryotes is driven by cyclin-dependent kinases (CDKs) and their cyclin partners. In vertebrates, the proper and timely duplication of the genome during S-phase relies on the coordinated activities of positive regulators such as CDK-cyclins and E2F, and negative regulators such as CDK inhibitors of the Cip/Kip and INK4 families. Recent and ongoing work indicates that many important regulators of G1- and S-phases are targeted for ubiquitination and subsequent degradation by the 26S proteasome. The proteolysis of key proteins during G1- and S-phases appears to be central for proper custodial regulation of DNA replication and the maintenance of cellular homeostasis in general. This review highlights the current literature regarding ubiquitin-mediated proteolysis of G1- and S-phase regulators and the control of events during the initiation and completion of DNA replication in vertebrates.
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