Rapid and specific degradation of endogenous proteins in mouse models using auxin-inducible degrons
Abstract
Auxin-inducible degrons are a chemical genetic tool for targeted protein degradation and are widely used to study protein function in cultured mammalian cells. Here we develop CRISPR-engineered mouse lines that enable rapid and highly specific degradation of tagged endogenous proteins in vivo. Most but not all cell types are competent for degradation. By combining ligand titrations with genetic crosses to generate animals with different allelic combinations, we show that degradation kinetics depend upon the dose of the tagged protein, ligand, and the E3 ligase substrate receptor TIR1. Rapid degradation of condensin I and condensin II - two essential regulators of mitotic chromosome structure - revealed that both complexes are individually required for cell division in precursor lymphocytes, but not in their differentiated peripheral lymphocyte derivatives. This generalisable approach provides unprecedented temporal control over the dose of endogenous proteins in mouse models, with implications for studying essential biological pathways and modelling drug activity in mammalian tissues.
Data availability
Proteomics data underlying Figure 6B have been submitted to the PRIDE database under accession PXD032374. All other primary data, including flow cytometry files, fluorescence imaging and uncropped western blot scans are available through the DRYAD digital repository at https://doi.org/10.5061/dryad.g1jwstqt9. Requests for the Rosa26Tir1 transgenic mouse line should be addressed to Bin Gu (guibin1@msu.edu), and requests for the Ncaph- and Ncaph2-AID:Clover lines should be addressed to Andrew Wood (Andrew.j.wood@ed.ac.uk).
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Rapid and specific degradation of endogenous proteins in mouse models using auxin-inducible degronsDryad Digital Repository, doi:10.5061/dryad.g1jwstqt9.
Article and author information
Author details
Funding
Medical Research Council
- Lewis Macdonald
- Gillian C Taylor
- Jennifer Margaret Brisbane
- Ersi Christodoulou
- Lucy Scott
- Andrew J Wood
Wellcome Trust (102560/Z/13/Z)
- Lewis Macdonald
- Gillian C Taylor
- Jennifer Margaret Brisbane
- Ersi Christodoulou
- Lucy Scott
- Andrew J Wood
Canadian Institutes of Health Research (JR FDN-143334)
- Janet Rossant
- Bin Gu
Medical Research Council (MC_PC_21040)
- Andrew J Wood
The funders had no role in study design, data collection and interpretation, or the decision to submit the work for publication.
Ethics
Animal experimentation: All animal work was approved by a University of Edinburgh internal ethics committee and was performed in accordance with institutional guidelines under license by the UK Home Office. AID knock-in alleles were generated under project license PPL 60/4424. Rosa26Tir1 knockin mouse lines were generated under the Canadian Council on Animal Care Guidelines for Use of Animals in Research and Laboratory Animal Care under protocols approved by the Centre for Phenogenomics Animal Care Committee (20-0026H). Experiments involving double transgenic animals were conducted under the authority of UK project license PPL P16EFF7EE
Reviewing Editor
- Guillaume Pavlovic, PHENOMIN, Institut Clinique de la Souris (ICS), CELPHEDIA, France
Publication history
- Received: February 18, 2022
- Accepted: May 19, 2022
- Accepted Manuscript published: June 23, 2022 (version 1)
Copyright
© 2022, Macdonald 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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Further reading
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CRISPR technology has made generation of gene knock-outs widely achievable in cells. However, once inactivated, their re-activation remains difficult, especially in diploid cells. Here, we present DExCon (Doxycycline-mediated endogenous gene Expression Control), DExogron (DExCon combined with auxin-mediated targeted protein degradation), and LUXon (light responsive DExCon) approaches which combine one-step CRISPR-Cas9-mediated targeted knockin of fluorescent proteins with an advanced Tet-inducible TRE3GS promoter. These approaches combine blockade of active gene expression with the ability to re-activate expression on demand, including activation of silenced genes. Systematic control can be exerted using doxycycline or spatiotemporally by light, and we demonstrate functional knock-out/rescue in the closely related Rab11 family of vesicle trafficking regulators. Fluorescent protein knock-in results in bright signals compatible with low-light live microscopy from monoallelic modification, the potential to simultaneously image different alleles of the same gene, and bypasses the need to work with clones. Protein levels are easily tunable to correspond with endogenous expression through cell sorting (DExCon), timing of light illumination (LUXon), or by exposing cells to different levels of auxin (DExogron). Furthermore, our approach allowed us to quantify previously unforeseen differences in vesicle dynamics, transferrin receptor recycling, expression kinetics, and protein stability among highly similar endogenous Rab11 family members and their colocalization in triple knock-in ovarian cancer cell lines.
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