Identification of genes essential for the cell death induced by OSW-1 using the Genome-wide CRISPR-Cas9 knockout (GeCKO) screening

The Golgi stress response is an important cytoprotective system that enhances Golgi function in response to cellular demand, while cells damaged by prolonged Golgi stress undergo cell death. OSW-1, a natural compound with anticancer activity, potently inhibits OSBP that transports cholesterol and phosphatidylinositol-4-phosphate (PI4P) at contact sites between the endoplasmic reticulum and the Golgi apparatus. Previously, we reported that OSW-1 induces the Golgi stress response, resulting in Golgi stress- induced transcription and cell death. However, the underlying molecular mechanism has been unknown. To reveal the mechanism of a novel pathway of the Golgi stress response regulating transcriptional induction and cell death (the PI4P pathway), we performed a genome-wide knockout screen and found that transcriptional induction as well as cell death induced by OSW-1 was repressed by the loss of regulators of PI4P synthesis, such as PITPNB and PI4KB. Our data indicate that OSW-1 induces Golgi stress-dependent transcriptional induction and cell death through dysregulation of the PI4P metabolism in the Golgi. Overall design: OSW-1 is a natural anticancer compound and activates the Golgi stress response. To search for genes essential for the cell death induced by OSW-1, we performed the Genome-wide CRISPR-Cas9 knockout (GeCKO) screening using OSW-1-resistant HeLa cells.