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Updated: Aug 19, 2026

Experimental Approaches to Study Mitochondrial Localization and Function of a Nuclear Cell Cycle Kinase, Cdk1
Published on: February 25, 2016
Cyclin-mediated export of human Orc1
1Molecular Oncology Laboratory, Gene Regulation Laboratory, Imperial Cancer Research Fund, 44 Lincoln's Inn Fields, London, WC2A 3PX, United Kingdom.
Abstract:
Viral cyclin/cdk6 complexes interact with and phosphorylate human Orc1, a component of the origin recognition complex (ORC) that functions in DNA replication. Here we assess the effect that viral cyclin has on the intracellular location of human Orc1, which is present in both nuclear and cytoplasmic pools. Overexpression of K cyclin or cyclin A results in Crm1-dependent export of Orc1 to the cytoplasm, and this process is dependent on the phosphorylation status of several cdk target sites in Orc1. These findings support a model where S phase promoting cyclin activity drives the export of a component of replication complexes.
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