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Updated: Jul 13, 2026
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Proliferation and Differentiation of Murine Myeloid Precursor 32D/G-CSF-R Cells
Published on: February 21, 2018
Cdc6 is a rate-limiting factor for proliferative capacity during HL60 cell differentiation
Laura R Barkley1, Hye Kyung Hong, Sarah R Kingsbury
1Wolfson Institute for Biomedical Research, University College London, The Cruciform Building, Gower Street, London, WC1E 6BT, UK.
Experimental Cell Research
|August 11, 2007
Summary
Cell differentiation halts proliferation by down-regulating the MCM licensing factor Cdc6, which controls DNA replication licensing. Restoring Cdc6 levels re-enables DNA replication in differentiating cells.
Area of Science:
- Cell Biology
- Molecular Biology
- Biochemistry
Background:
- Cell proliferation is tightly regulated by growth signaling pathways.
- Exiting the cell cycle involves down-regulation of DNA replication licensing factors like MCM (minichromosome maintenance) proteins.
- This down-regulation reduces proliferative capacity in quiescent, differentiated, or senescent cells.
Purpose of the Study:
- To biochemically investigate the link between DNA replication origin licensing and cell differentiation.
- To identify the molecular mechanisms controlling the loss of proliferative capacity during differentiation.
Main Methods:
- Utilized the HL60 monocyte/macrophage differentiation model.
- Employed a cell-free DNA replication assay.
- Investigated the role of Cdc6 (activator of the MCM complex) during differentiation.
Main Results:
- Down-regulation of Cdc6 acts as a molecular switch for loss of proliferative capacity during differentiation.
- Recombinant Cdc6 protein restored DNA replication in differentiating cells.
- Overexpression of Cdc6, particularly a non-phosphorylatable mutant (Cdc6A4), extended cell proliferation.
- CDK phosphorylation of Cdc6 is linked to its down-regulation and subsequent loss of proliferation.
Conclusions:
- Cdc6 plays a critical role in repressing DNA replication origin licensing during cell differentiation.
- Cdc6 down-regulation, mediated by CDK phosphorylation, is a key event leading to the loss of proliferative capacity.
- Targeting Cdc6 may offer strategies to modulate cell proliferation in differentiation contexts.
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