The Dependency Map (DepMap) is a genome-wide pooled CRISPR-Cas9 knockout proliferation screen conducted in more than 700 cancer cell lines spanning many different tumor lineages. Each cell line in the DepMap contains a unique barcode, and each gene knockout is assigned a “dependency score” on a per cell-line basis which quantifies the rate of CRISPR-Cas9 guide drop. It has been found that proteins with similar DepMap scores across cell lines, a phenomenon known as co-dependent genes, have closely related biological functions. This can include activity in the same or parallel pathways or membership in the same protein complex or the same pathway.
We identified the strongest seven co-dependent genes (“Symbol”) for DUBs and ran GO enrichment analysis. We used Biogrid, IntAct, and Pathway Commons PPIDs, and the NURSA protein-protein interaction databases (PPIDs) to determine whether co-dependent genes interact with one another. The “Evidence” column contains the PPIDs in which the interaction appears as well as whether there is support for the association by an INDRA statement. As another approach to identify potential interactors, we looked at proteomics data from the Broad Institute's Cancer Cell Line Encyclopedia (CCLE) for proteins whose expression across ~375 cell lines strongly correlated with the abundance of each DUB; it has previously been observed that proteins in the same complex are frequently significantly co-expressed. The correlations and associated p-values in the CCLE proteomics dataset are provided. And, we determined whether co-dependent genes yield similar transcriptomic signatures in the Broad Institute's Connectivity Map (CMap). A CMap score greater than 90 is considered significantly similar.
Symbol | Name | DepMap Correlation | Evidence | CCLE Correlation | CCLE Z-score | CCLE p-value (adj) | CCLE Significant | CMAP Score | CMAP Type |
---|---|---|---|---|---|---|---|---|---|
CDKN1A | cyclin dependent kinase inhibitor 1A | -0.323 | -0.10 | -0.63 | 3.49e-01 | ||||
TP53 | tumor protein p53 | -0.318 | -0.10 | -0.62 | 2.94e-01 | ||||
ADRM1 | ADRM1 26S proteasome ubiquitin receptor | 0.288 | 0.16 | 0.78 | 6.82e-02 | ||||
CHEK2 | checkpoint kinase 2 | -0.251 | 0.21 | 1.08 | 1.08e-02 | ||||
TP53BP1 | tumor protein p53 binding protein 1 | -0.248 | -0.30 | -1.76 | 1.24e-04 | ||||
MDM2 | MDM2 proto-oncogene | 0.244 | -0.11 | -0.67 | 4.03e-01 | ||||
IPO9 | importin 9 | 0.223 | 0.32 | 1.68 | 4.33e-05 |
Gene set enrichment analysis was done on the genes correlated with USP38using the terms from Gene Ontology and gene sets derived from the Gene Ontology Annotations database via MSigDB.
Using the biological processes and other Gene Ontology terms from well characterized DUBs as a positive control, several gene set enrichment analyses were considered. Threshold-less methods like GSEA had relatively poor results. Over-representation analysis with a threshold of of the top 7 highest absolute value Dependency Map correlations yielded the best results and is reported below.
GO Identifier | GO Name | GO Type | p-value | p-value (adj.) | q-value |
---|---|---|---|---|---|
GO:0071479 | cellular response to ionizing radiation | Biological Process | 1.33e-11 | 7.07e-09 | 1.93e-09 |
GO:0010212 | response to ionizing radiation | Biological Process | 5.60e-10 | 2.98e-07 | 3.77e-08 |
GO:0031570 | DNA integrity checkpoint | Biological Process | 7.79e-10 | 4.15e-07 | 3.77e-08 |
GO:0071478 | cellular response to radiation | Biological Process | 1.97e-09 | 1.05e-06 | 7.17e-08 |
GO:0000075 | cell cycle checkpoint | Biological Process | 3.76e-09 | 2.01e-06 | 9.90e-08 |
GO:0072395 | signal transduction involved in cell cycle checkpoint | Biological Process | 7.39e-09 | 3.94e-06 | 1.53e-07 |
GO:0090399 | replicative senescence | Biological Process | 1.12e-08 | 5.96e-06 | 1.81e-07 |
GO:0071158 | positive regulation of cell cycle arrest | Biological Process | 1.12e-08 | 5.98e-06 | 1.81e-07 |
GO:0044774 | mitotic DNA integrity checkpoint | Biological Process | 3.30e-08 | 1.76e-05 | 3.83e-07 |
GO:0071156 | regulation of cell cycle arrest | Biological Process | 3.43e-08 | 1.83e-05 | 3.83e-07 |
GO:0071214 | cellular response to abiotic stimulus | Biological Process | 2.79e-08 | 1.49e-05 | 3.83e-07 |
GO:0030330 | DNA damage response, signal transduction by p53 class mediator | Biological Process | 3.18e-08 | 1.69e-05 | 3.83e-07 |
GO:1902807 | negative regulation of cell cycle G1/S phase transition | Biological Process | 7.25e-08 | 3.86e-05 | 7.46e-07 |
GO:0042770 | signal transduction in response to DNA damage | Biological Process | 7.71e-08 | 4.11e-05 | 7.46e-07 |
GO:0071480 | cellular response to gamma radiation | Biological Process | 1.12e-07 | 5.96e-05 | 1.02e-06 |
GO:0009314 | response to radiation | Biological Process | 1.45e-07 | 7.73e-05 | 1.24e-06 |
GO:0007093 | mitotic cell cycle checkpoint | Biological Process | 1.89e-07 | 1.01e-04 | 1.53e-06 |
GO:1902806 | regulation of cell cycle G1/S phase transition | Biological Process | 4.09e-07 | 2.18e-04 | 3.13e-06 |
GO:0010332 | response to gamma radiation | Biological Process | 8.00e-07 | 4.26e-04 | 5.81e-06 |
GO:0007050 | cell cycle arrest | Biological Process | 9.06e-07 | 4.83e-04 | 6.27e-06 |
GO:0072331 | signal transduction by p53 class mediator | Biological Process | 1.28e-06 | 6.82e-04 | 8.05e-06 |
GO:1901988 | negative regulation of cell cycle phase transition | Biological Process | 1.26e-06 | 6.71e-04 | 8.05e-06 |
GO:0002039 | p53 binding | Molecular Function | 1.33e-06 | 7.09e-04 | 8.05e-06 |
GO:0097193 | intrinsic apoptotic signaling pathway | Biological Process | 1.76e-06 | 9.36e-04 | 1.02e-05 |
GO:0044843 | cell cycle G1/S phase transition | Biological Process | 1.88e-06 | 1.00e-03 | 1.05e-05 |
GO:0090068 | positive regulation of cell cycle process | Biological Process | 1.98e-06 | 1.06e-03 | 1.07e-05 |
GO:0072332 | intrinsic apoptotic signaling pathway by p53 class mediator | Biological Process | 2.22e-06 | 1.18e-03 | 1.12e-05 |
GO:0044389 | ubiquitin-like protein ligase binding | Molecular Function | 2.23e-06 | 1.19e-03 | 1.12e-05 |
GO:0034644 | cellular response to UV | Biological Process | 2.40e-06 | 1.28e-03 | 1.16e-05 |
GO:2001021 | negative regulation of response to DNA damage stimulus | Biological Process | 2.59e-06 | 1.38e-03 | 1.21e-05 |
GO:0045930 | negative regulation of mitotic cell cycle | Biological Process | 3.20e-06 | 1.71e-03 | 1.44e-05 |
GO:0090400 | stress-induced premature senescence | Biological Process | 3.26e-06 | 1.74e-03 | 1.44e-05 |
GO:0010948 | negative regulation of cell cycle process | Biological Process | 4.17e-06 | 2.22e-03 | 1.78e-05 |
GO:0045787 | positive regulation of cell cycle | Biological Process | 6.67e-06 | 3.56e-03 | 2.77e-05 |
GO:0007569 | cell aging | Biological Process | 7.66e-06 | 4.08e-03 | 3.09e-05 |
GO:0071482 | cellular response to light stimulus | Biological Process | 1.03e-05 | 5.48e-03 | 4.04e-05 |
GO:0009411 | response to UV | Biological Process | 1.29e-05 | 6.87e-03 | 4.88e-05 |
GO:1901987 | regulation of cell cycle phase transition | Biological Process | 1.31e-05 | 6.99e-03 | 4.88e-05 |
GO:0042772 | DNA damage response, signal transduction resulting in transcription | Biological Process | 1.58e-05 | 8.43e-03 | 5.75e-05 |
GO:0046827 | positive regulation of protein export from nucleus | Biological Process | 2.44e-05 | 1.30e-02 | 8.65e-05 |
GO:1901796 | regulation of signal transduction by p53 class mediator | Biological Process | 2.81e-05 | 1.50e-02 | 9.72e-05 |
GO:0071157 | negative regulation of cell cycle arrest | Biological Process | 2.94e-05 | 1.57e-02 | 9.93e-05 |
GO:2001020 | regulation of response to DNA damage stimulus | Biological Process | 4.59e-05 | 2.45e-02 | 1.52e-04 |
GO:0010165 | response to X-ray | Biological Process | 5.40e-05 | 2.88e-02 | 1.74e-04 |
GO:0097718 | disordered domain specific binding | Molecular Function | 5.76e-05 | 3.07e-02 | 1.82e-04 |
GO:0046825 | regulation of protein export from nucleus | Biological Process | 9.04e-05 | 4.82e-02 | 2.77e-04 |
GO:0031668 | cellular response to extracellular stimulus | Biological Process | 9.15e-05 | 4.88e-02 | 2.77e-04 |
The following table shows the significantly differentially expressed genes after knocking out USP38 using CRISPR-Cas9.
Symbol | Name | log2-fold-change | p-value | p-value (adj.) |
---|---|---|---|---|
IFIT3 | interferon induced protein with tetratricopeptide repeats 3 | 6.29e-01 | 3.83e-07 | 4.23e-03 |
UBC | ubiquitin C | 3.38e-01 | 3.28e-07 | 4.23e-03 |
HMGB2 | high mobility group box 2 | -4.77e-01 | 4.22e-06 | 3.10e-02 |
There were too few differentially expressed genes to run a meaningful GSEA.
INDRA was used to automatically assemble known mechanisms related to USP38 from literature and knowledge bases. The first section shows only DUB activity and the second shows all other results.