Triazoles inhibit cholesterol export from lysosomes by binding to NPC1

• DOI: 10.1073/pnas.1619571114
• Publication Date: 2016-12-20T03:00:44Z
• Authors: Michael N. Trinh; Feiran Lu; Xiaochun Li; Akash Das; Qiren Liang; Jef K. De Brabander; Michael S. Brown; Joseph L. Goldstein
• Keywords: 0303 health sciences; Antifungal Agents; Binding Sites; Membrane Glycoproteins; Biological Transport; CHO Cells; Triazoles; Endocytosis; Cell Line; 3. Good health; 03 medical and health sciences; Cholesterol; Cricetulus; Ketoconazole; Protein Domains; Animals; Androstenes; Itraconazole; Carrier Proteins; Lysosomes; Protein Binding

SignificanceIn animal cells, cholesterol is essential for the assembly of membranes and production of steroid hormones and bile acids. Cells obtain cholesterol through receptor-mediated endocytosis of LDL into lysosomes. After lysosomal degradation, LDL-derived cholesterol must cross the lysosomal membrane to execute its functions. Lysosomal export is mediated by Niemann–Pick C1 (NPC1), a membrane protein. Here we show that the triazole drugs posaconazole and itraconazole inhibit lysosomal cholesterol export. A photoactivatable derivative of posaconazole cross-links to NPC1 in intact cells and to purified NPC1 in lipid nanodiscs. A point mutation in the membrane domain of NPC1 prevents lysosomal export of cholesterol and blocks posaconazole cross-linking.