A Chemogenetic CRISPR Knock-out Screen Uncovers Synergy Between Ubiquitin Signalling and C16orf72/HAPSTR1 for safeguarding S-phase integrity.

To comprehensively identify ubiquitin signalling components critical for cell proliferation, we employed a chemical-genetic CRISPR knock-out screen, exploiting the first-in-class ubiquitin E1 inhibitor TAK-243.

Our findings provide a systems view of key protein networks underpinning cell cycle progression. We identified 239 genes, including C16orf72/HAPSTR1, whose ablation rendered cells sensitive to diminished ubiquitin signalling, and 55 genes that conferred resistance under the same conditions. We reveal broad transcriptional changes accompanied with proteome-wide alterations in the ubiquitin signalling landscape as a function of HAPSTR1 expression and show HAPSTR1 is involved in homeostasis of cell cycle regulators such as CDK6 and CDC6.