The cholesterol pathway of the Golgi stress response induces cell death and transcription of Golgi-related genes through metabolic dysregulation of phosphatidylinositol-4-phosphate
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 to ensure the survival of organisms. OSW-1, a natural compound with anticancer activity, acts as a potent inhibitor of 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 cholesterol pathway), we performed a genome-wide knockout screen and found that transcriptional induction as well as cell death induced by OSW-1 was repressed in HeLa cells deficient in factors involved in the PI4P metabolism, such as PITPNB and PI4KB genes. Our data indicate that OSW-1 induces Golgi stress-dependent transcriptional induction and cell death through dysregulation of the PI4P metabolism in the Golgi apparatus.