An engineered transcriptional reporter of protein localization identifies regulators of mitochondrial and ER membrane protein trafficking in high-throughput CRISPRi screens
- Stanford University, United States
- Broad Institute of MIT and Harvard, United States
- Whitehead Institute, United States
Abstract
The trafficking of specific protein cohorts to correct subcellular locations at correct times is essential for every signaling and regulatory process in biology. Gene perturbation screens could provide a powerful approach to probe the molecular mechanisms of protein trafficking, but only if protein localization or mislocalization can be tied to a simple and robust phenotype for cell selection, such as cell proliferation or fluorescence-activated cell sorting (FACS). To empower the study of protein trafficking processes with gene perturbation, we developed a genetically-encoded molecular tool named HiLITR. HiLITR converts protein colocalization into proteolytic release of a membrane-anchored transcription factor, which drives the expression of a chosen reporter gene. Using HiLITR in combination with FACS-based CRISPRi screening in human cell lines, we identified genes that influence the trafficking of mitochondrial and ER tail-anchored proteins. We show that loss of the SUMO E1 component SAE1 results in mislocalization and destabilization of many mitochondrial tail-anchored proteins. We also demonstrate a distinct regulatory role for EMC10 in the ER membrane complex, opposing the transmembrane-domain insertion activity of the complex. Through transcriptional integration of complex cellular functions, HiLITR expands the scope of biological processes that can be studied by genetic perturbation screening technologies.
Data availability
Lead contact: Further information and requests for resources or reagents should be directed to the lead contact, Alice Ting (ayting@stanford.edu)Materials availability: Plasmids generated in the study have been deposited to Addgene or are available upon request (Supplementary File 1)Data and code availability: HiLITR screen sequencing data has been deposited to Dryad (doi:10.5061/dryad.tb2rbp00n). The original mass spectra and the protein sequence database used for searches have been deposited in the public proteomics repository MassIVE (http://massive.ucsd.edu) and are accessible at ftp://massive.ucsd.edu/MSV000087769/.
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HiLITR CRISPR screenshttps://creativecommons.org/publicdomain/zero/1.0/.
Article and author information
Author details
Mateo Lopez Sanchez
Funding
National Institute of Mental Health (MH119353)
- Alice Y Ting
NIH Office of the Director (1DP2HD084069-01)
- Michael C Bassik
National Science Foundation (1656518)
- David Yao
Stanford Bio-X
- Robert W Coukos
National Institute of Standards and Technology
- Robert W Coukos
National Human Genome Research Institute (2T32HG000044)
- Robert W Coukos
- David Yao
The funders had no role in study design, data collection and interpretation, or the decision to submit the work for publication.
Copyright
© 2021, Coukos 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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An engineered transcriptional reporter of protein localization identifies regulators of mitochondrial and ER membrane protein trafficking in high-throughput CRISPRi screens
eLife 10:e69142.
https://doi.org/10.7554/eLife.69142
