Cyclin F drives proliferation through SCF-dependent degradation of the retinoblastoma-like tumor suppressor p130/RBL2
- University of North Carolina at Chapel Hill, United States
- University of California, Santa Cruz, United States
Abstract
Cell cycle gene expression programs fuel proliferation and are universally dysregulated in cancer. The retinoblastoma (RB)-family of proteins, RB1, RBL1/p107 and RBL2/p130, coordinately repress cell cycle gene expression, inhibiting proliferation and suppressing tumorigenesis. Phosphorylation of RB-family proteins by cyclin dependent kinases is firmly established. Like phosphorylation, ubiquitination is essential to cell cycle control, and numerous proliferative regulators, tumor suppressors, and oncoproteins are ubiquitinated. However, little is known about the role of ubiquitin signaling in controlling RB-family proteins. A systems genetics analysis of CRISPR/Cas9 screens suggested the potential regulation of the RB-network by cyclin F, a substrate recognition receptor for the SCF family of E3 ligases. We demonstrate that RBL2/p130 is a direct substrate of SCFcyclin F. We map a cyclin F regulatory site to a flexible linker in the p130 pocket domain, and show that this site mediates binding, stability, and ubiquitination. Expression of a mutant version of p130, which cannot be ubiquitinated, severely impaired proliferative capacity and cell cycle progression. Consistently, we observed reduced expression of cell cycle gene transcripts, as well a reduced abundance of cell cycle proteins, analyzed by quantitative, iterative immunofluorescent imaging. These data suggest a key role for SCFcyclin F in the CDK-RB network and raise the possibility that aberrant p130 degradation could dysregulate the cell cycle in human cancers.
Data availability
Unprocessed, uncropped, immunoblots are made available in the supplemental source data. All raw, unprocessed imaging data is available at Dryad. Raw data related to cell proliferation assays (cell counting and Presto-blue analysis), RT-qPCR, immunoblot quantification for cycloheximide chase experiments and flow cytometry is available in the supplemental source data. All reagents related to this work will be made fully available upon request.
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Data from: Cyclin F drives proliferation through SCF-dependent degradation of the retinoblastoma-like tumor suppressor p130/RBL2Dryad Digital Repository, doi:10.5061/dryad.69p8cz93d.
Article and author information
Author details
Michael J Emanuele
Funding
National Institute of General Medical Sciences (R01GM120309)
- Taylor P Enrico
- Xianxi Wang
- Michael J Emanuele
National Institute of General Medical Sciences (NIGMS,T32 GM007040)
- Taylor P Enrico
National Institute of General Medical Sciences (R01GM134231)
- Taylor P Enrico
- Xianxi Wang
- Michael J Emanuele
National Institute of General Medical Sciences (R35GM128855)
- Elizaveta T Wick
- Nicholas G Brown
American Cancer Society (RSG-18-220-01-TBG)
- Taylor P Enrico
- Xianxi Wang
- Michael J Emanuele
National Cancer Institute (R01CA163834)
- Elizaveta T Wick
National Institute of General Medical Sciences (R01GM127707)
- Peter Ngoi
- Seth M Rubin
National Institute of General Medical Sciences (GM138834)
- Wayne Stallaert
- Jeremy Purvis
National Institute of General Medical Sciences (DP2-HD091800)
- Wayne Stallaert
- Jeremy Purvis
National Science Foundation (1845796)
- Jeremy Purvis
The funders had no role in study design, data collection and interpretation, or the decision to submit the work for publication.
Copyright
© 2021, Enrico et al.
This article is distributed under the terms of the Creative Commons Attribution License permitting unrestricted use and redistribution provided that the original author and source are credited.
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Cyclin F drives proliferation through SCF-dependent degradation of the retinoblastoma-like tumor suppressor p130/RBL2
eLife 10:e70691.
https://doi.org/10.7554/eLife.70691
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