scholarly journals Genome-Wide CRISPR Screen Reveals Autophagy Disruption as the Convergence Mechanism That Regulates the NRF2 Transcription Factor

2019 ◽  
Vol 39 (13) ◽  
Author(s):  
Michael J. Kerins ◽  
Pengfei Liu ◽  
Wang Tian ◽  
William Mannheim ◽  
Donna D. Zhang ◽  
...  
Keyword(s):  
Transcription Factor ◽  
Negative Regulator ◽  
Cell Type ◽  
Genome Wide ◽  
A Genome ◽  
Nrf2 Activation ◽  
Crispr Screen ◽  
Short Palindromic Repeat ◽  
Intimate Link ◽  
Convergence Mechanism

ABSTRACT The nuclear factor (erythroid 2)-like 2 (NRF2 or NFE2L2) transcription factor regulates the expression of many genes that are critical in maintaining cellular homeostasis. Its deregulation has been implicated in many diseases, including cancer and metabolic and neurodegenerative diseases. While several mechanisms by which NRF2 can be activated have gradually been identified over time, a more complete regulatory network of NRF2 is still lacking. Here we show through a genome-wide clustered regularly interspaced short palindromic repeat (CRISPR) screen that a total of 273 genes, when knocked out, will lead to sustained NRF2 activation. Pathway analysis revealed a significant overrepresentation of genes (18 of the 273 genes) involved in autophagy. Molecular validation of a subset of the enriched genes identified 8 high-confidence genes that negatively regulate NRF2 activity irrespective of cell type: ATG12, ATG7, GOSR1, IFT172, NRXN2, RAB6A, VPS37A, and the well-known negative regulator of NRF2, KEAP1. Of these, ATG12, ATG7, KEAP1, and VPS37A are known to be involved in autophagic processes. Our results present a comprehensive list of NRF2 negative regulators and reveal an intimate link between autophagy and NRF2 regulation.

scholarly journals Computational prediction of CRISPR-impaired non-coding regulatory regions

2020 ◽  
Author(s):  
Nina Baumgarten ◽  
Florian Schmidt ◽  
Martin Wegner ◽  
Marie Hebel ◽  
Manuel Kaulich ◽  
...  
Keyword(s):  
Computational Prediction ◽  
Regulatory Elements ◽  
Cell Type ◽  
Coding Regions ◽  
Gene Coding ◽  
Genome Wide ◽  
A Genome ◽  
Crispr Screen ◽  
Genomic Regions ◽  
Made In

AbstractGenome-wide CRISPR screens are becoming more widespread and allow the simultaneous interrogation of thousands of genomic regions. Although recent progress has been made in the analysis of CRISPR screens, it is still an open problem how to interpret CRISPR mutations in non-coding regions of the genome. Most of the tools concentrate on the interpretation of mutations introduced in gene coding regions. We introduce a computational pipeline that uses epigenomic information about regulatory elements for the interpretation of CRISPR mutations in non-coding regions. We illustrate our approach on the analysis of a genome-wide CRISPR screen in hTERT-RPE-1 cells and reveal novel regulatory elements that mediate chemoresistance against doxorubicin in these cells. We infer links to established and to novel chemoresistance genes. Our approach is general and can be applied on any cell type and with different CRISPR enzymes.

scholarly journals Genome-wide CRISPR screen identifies noncanonical NF-κB signaling as a regulator of density-dependent proliferation

eLife ◽  
2020 ◽  
Vol 9 ◽  
Author(s):  
Maria Fomicheva ◽  
Ian G Macara
Keyword(s):  
Cell Cycle ◽  
Epithelial Cells ◽  
Kinase Inhibitors ◽  
Mammary Epithelial Cells ◽  
Mammary Epithelial ◽  
Negative Regulator ◽  
Density Dependent ◽  
Genome Wide ◽  
A Genome ◽  
Crispr Screen

Epithelial cells possess intrinsic mechanisms to maintain an appropriate cell density for normal tissue morphogenesis and homeostasis. Defects in such mechanisms likely contribute to hyperplasia and cancer initiation. To identify genes that regulate the density-dependent proliferation of murine mammary epithelial cells, we developed a fluorescence-activated cell sorting assay based on fluorescence ubiquitination cell cycle indicator, which marks different stages of the cell cycle with distinct fluorophores. Using this powerful assay, we performed a genome-wide CRISPR/Cas9 knockout screen, selecting for cells that proliferate normally at low density but continue to divide at high density. Unexpectedly, one top hit was Traf3, a negative regulator of NF-κB signaling that has never previously been linked to density-dependent proliferation. We demonstrate that loss of Traf3 specifically activates noncanonical NF-κB signaling. This in turn triggers an innate immune response and drives cell division independently of known density-dependent proliferation mechanisms, including YAP/TAZ signaling and cyclin-dependent kinase inhibitors, by blocking entry into quiescence.

scholarly journals Genome-Wide CRISPR Screen Identifies Non-Canonical NF-κB Signaling as a Potent Regulator of Density-dependent Proliferation

2020 ◽  
Author(s):  
Maria Fomicheva ◽  
Ian G. Macara
Keyword(s):  
Epithelial Cells ◽  
Kinase Inhibitors ◽  
Mammary Epithelial Cells ◽  
Mammary Epithelial ◽  
Negative Regulator ◽  
Density Dependent ◽  
Genome Wide ◽  
A Genome ◽  
Cancer Initiation ◽  
Crispr Screen

ABSTRACTEpithelial cells possess intrinsic mechanisms to maintain an appropriate cell density for normal tissue morphogenesis and homeostasis. Defects in such mechanisms likely contribute to hyperplasia and cancer initiation. To identify genes that regulate the density-dependent proliferation of murine mammary epithelial cells, we developed a fluorescence-activated cell sorting assay based on FUCCI, which marks different stages of the cell cycle with distinct fluorophores. Using this powerful assay, we performed a genome-wide CRISPR/Cas9 knockout screen, selecting for cells that proliferate normally at low density but continue to divide at high density. Unexpectedly, one top hit was Traf3, a negative regulator of NF-κB signaling that has never previously been linked to density-dependent proliferation. We demonstrate that loss of Traf3 specifically activates non-canonical NF-κB signaling. This in turn triggers an innate immune response and drives cell division independently of known density-dependent proliferation mechanisms, including YAP/TAZ signaling and cyclin kinase inhibitors, by blocking entry into quiescence.

scholarly journals Genome-wide screens identify Toxoplasma gondii determinants of parasite fitness in IFNγ-activated murine macrophages

2020 ◽  
Vol 11 (1) ◽  
Author(s):  
Yifan Wang ◽  
Lamba Omar Sangaré ◽  
Tatiana C. Paredes-Santos ◽  
Musa A. Hassan ◽  
Shruthi Krishnamurthy ◽  
...  
Keyword(s):  
Dense Granule ◽  
Cell Type ◽  
Murine Macrophages ◽  
Parasite Fitness ◽  
Early Immune Response ◽  
Host Cytoplasm ◽  
Genome Wide ◽  
A Genome ◽  
Crispr Screen

Abstract Macrophages play an essential role in the early immune response against Toxoplasma and are the cell type preferentially infected by the parasite in vivo. Interferon gamma (IFNγ) elicits a variety of anti-Toxoplasma activities in macrophages. Using a genome-wide CRISPR screen we identify 353 Toxoplasma genes that determine parasite fitness in naїve or IFNγ-activated murine macrophages, seven of which are further confirmed. We show that one of these genes encodes dense granule protein GRA45, which has a chaperone-like domain, is critical for correct localization of GRAs into the PVM and secretion of GRA effectors into the host cytoplasm. Parasites lacking GRA45 are more susceptible to IFNγ-mediated growth inhibition and have reduced virulence in mice. Together, we identify and characterize an important chaperone-like GRA in Toxoplasma and provide a resource for the community to further explore the function of Toxoplasma genes that determine fitness in IFNγ-activated macrophages.

scholarly journals A genome-wide CRISPR screen identifies UFMylation and TRAMP-like complexes as host factors required for hepatitis A virus infection

Cell Reports ◽  
2021 ◽  
Vol 34 (11) ◽  
pp. 108859
Author(s):  
Jessie Kulsuptrakul ◽  
Ruofan Wang ◽  
Nathan L. Meyers ◽  
Melanie Ott ◽  
Andreas S. Puschnik
Keyword(s):  
Virus Infection ◽  
Hepatitis A ◽  
Hepatitis A Virus ◽  
Host Factors ◽  
Genome Wide ◽  
A Genome ◽  
Crispr Screen

scholarly journals A Genome-wide CRISPR Screen Identifies CDC25A as a Determinant of Sensitivity to ATR Inhibitors

2016 ◽  
Vol 62 (2) ◽  
pp. 307-313 ◽  
Author(s):  
Sergio Ruiz ◽  
Cristina Mayor-Ruiz ◽  
Vanesa Lafarga ◽  
Matilde Murga ◽  
Maria Vega-Sendino ◽  
...  
Keyword(s):  
Genome Wide ◽  
A Genome ◽  
Crispr Screen

scholarly journals Functional CRISPR screening identifies the ufmylation pathway as a regulator of SQSTM1/p62

eLife ◽  
2016 ◽  
Vol 5 ◽  
Author(s):  
Rowena DeJesus ◽  
Francesca Moretti ◽  
Gregory McAllister ◽  
Zuncai Wang ◽  
Phil Bergman ◽  
...  
Keyword(s):  
Adaptor Protein ◽  
Er Stress Response ◽  
Genome Wide ◽  
A Genome ◽  
Crispr Screen ◽  
Selection Step ◽  
A Cell ◽  
Cell Type Specific ◽  
Cellular Pathways ◽  
Mtor Signalling

SQSTM1 is an adaptor protein that integrates multiple cellular signaling pathways and whose expression is tightly regulated at the transcriptional and post-translational level. Here, we describe a forward genetic screening paradigm exploiting CRISPR-mediated genome editing coupled to a cell selection step by FACS to identify regulators of SQSTM1. Through systematic comparison of pooled libraries, we show that CRISPR is superior to RNAi in identifying known SQSTM1 modulators. A genome-wide CRISPR screen exposed MTOR signalling and the entire macroautophagy machinery as key regulators of SQSTM1 and identified several novel modulators including HNRNPM, SLC39A14, SRRD, PGK1 and the ufmylation cascade. We show that ufmylation regulates SQSTM1 by eliciting a cell type-specific ER stress response which induces SQSTM1 expression and results in its accumulation in the cytosol. This study validates pooled CRISPR screening as a powerful method to map the repertoire of cellular pathways that regulate the fate of an individual target protein.

scholarly journals Genome-wide CRISPR screen identifies regulators of MAPK and MTOR pathways mediating sorafenib resistance in acute myeloid leukemia

Haematologica ◽  
2020 ◽  
Author(s):  
Alisa Damnernsawad ◽  
Daniel Bottomly ◽  
Stephen E. Kurtz ◽  
Christopher A. Eide ◽  
Shannon K. McWeeney ◽  
...  
Keyword(s):  
Acute Myeloid Leukemia ◽  
Myeloid Leukemia ◽  
Ex Vivo ◽  
Mek Inhibitors ◽  
Genome Wide ◽  
A Genome ◽  
Flt3 Mutations ◽  
Flt3 Inhibitors ◽  
Crispr Screen ◽  
Acute Myeloid

Drug resistance impedes the long-term effect of targeted therapies in acute myeloid leukemia (AML), necessitating the identification of mechanisms underlying resistance. Approximately 25% of AML patients carry FLT3 mutations and develop post-treatment insensitivity to FLT3 inhibitors, including sorafenib. Using a genome-wide CRISPR screen, we identified LZTR1, NF1, TSC1 or TSC2, negative regulators of the MAPK and MTOR pathways, as mediators of sorafenib resistance. Analyses of ex vivo drug sensitivity assays in FLT3-ITD AML patient samples revealed lower expression of LZTR1, NF1, and TSC2 correlated with sorafenib sensitivity. Importantly, MAPK and/or MTOR complex1 (MTORC1) activity were upregulated in AML cells made resistant to several FLT3 inhibitors, including crenolanib, quizartinib, or sorafenib. These cells were sensitive to MEK inhibitors, and the combination of FLT3 and MEK inhibitors showed enhanced efficacy, suggesting its effectiveness in AML patients with FLT3 mutations and those with resistance to FLT3 inhibitors.

Controlling quality and amount of mitochondria by mitophagy: insights into the role of ubiquitination and deubiquitination

2016 ◽  
Vol 397 (7) ◽  
pp. 637-647 ◽  
Author(s):  
Tao Tan ◽  
Marcel Zimmermann ◽  
Andreas S. Reichert
Keyword(s):  
Mammalian Cells ◽  
Mitochondrial Fission ◽  
Baker’S Yeast ◽  
Negative Regulator ◽  
Mitochondrial Outer Membrane ◽  
Baker's Yeast ◽  
Genome Wide ◽  
A Genome ◽  
Autophagy Pathway ◽  
Quantity Control

Abstract Mitophagy is a selective autophagy pathway conserved in eukaryotes and plays an essential role in mitochondrial quality and quantity control. Mitochondrial fission and fusion cycles maintain a certain amount of healthy mitochondria and allow the isolation of damaged mitochondria for their elimination by mitophagy. Mitophagy can be classified into receptor-dependent and ubiquitin-dependent pathways. The mitochondrial outer membrane protein Atg32 is identified as the only known receptor for mitophagy in baker’s yeast, whereas mitochondrial proteins FUNDC1, NIX/BNIP3L, BNIP3 and Bcl2L13 are recognized as mitophagy receptors in mammalian cells. Earlier studies showed that ubiquitination and deubiquitination occurs in yeast, yet there is no direct evidence for an ubiquitin-dependent mitophagy pathway in this organism. In contrast, a ubiquitin-/PINK1-/Parkin-dependent mitophagy pathway was unraveled and was extensively characterized in mammals in recent years. Recently, a quantitative method termed synthetic quantitative array (SQA) technology was developed to identify modulators of mitophagy in baker’s yeast on a genome-wide level. The Ubp3-Bre5 deubiquitination complex was found as a negative regulator of mitophagy while promoting other autophagic pathways. Here we discuss how ubiquitination and deubiquitination regulates mitophagy and other selective forms of autophagy and what argues for using baker’s yeast as a model to study the ubiquitin-dependent mitophagy pathway.

Sign in / Sign up

Export Citation Format

Share Document