Oxysterol-binding protein (OSBP)-related protein 4 (ORP4) is essential for cell proliferation and survival

Abstract

Background: The function of oxysterol-binding protein-related protein (ORP4) is unknown. Results: Silencing ORP4L or all ORP4 isoforms triggers growth arrest and apoptosis, which is suppressed by H-Ras and involves the C-terminal lipid binding domain. Conclusion: ORP4 is a sterol and PI-4P-binding protein required for survival and proliferation of immortalized and transformed cells. Significance: This is the first study to identify a mammalian ORP with growth regulatory activity. © 2014 by The American Society for Biochemistry and Molecular Biology, Inc. Published in the U.S.A.