title: Ikarugamycin: A Natural Product Inhibitor of Clathrin-Mediated Endocytosis.
abstract: Ikarugamycin (IKA) is a previously discovered antibiotic, which has been shown to inhibit the uptake of oxidized low-density lipoproteins in macrophages. Furthermore, several groups have previously used IKA to inhibit clathrin-mediated endocytosis (CME) in plant cell lines. However, detailed characterization of IKA has yet to be performed. Consequently, we performed biochemistry and microscopy experiments to further characterize the effects of IKA on CME. We show that IKA has an IC50 of 2.7 μm in H1299 cells and acutely inhibits CME, but not other endocytic pathways, in a panel of cell lines. Although long-term incubation with IKA has cytotoxic effects, the short-term inhibitory effects on CME are reversible. Thus, IKA can be a useful tool for probing routes of endocytic trafficking.
authors.affiliation: Department of Cell Biology, UT Southwestern Medical Center, Dallas, TX, USA.
authors.forename: Sarah R
authors.initials: SR
authors.lastname: Elkin
authors.affiliation: Department of Biochemistry, UT Southwestern Medical Center, Dallas, TX, USA.
authors.forename: Nathaniel W
authors.initials: NW
authors.lastname: Oswald
authors.affiliation: Department of Cell Biology, UT Southwestern Medical Center, Dallas, TX, USA.
authors.forename: Dana K
authors.initials: DK
authors.lastname: Reed
authors.affiliation: Department of Cell Biology, UT Southwestern Medical Center, Dallas, TX, USA.
authors.forename: Marcel
authors.initials: M
authors.lastname: Mettlen
authors.affiliation: Department of Biochemistry, UT Southwestern Medical Center, Dallas, TX, USA.
authors.forename: John B
authors.initials: JB
authors.lastname: MacMillan
authors.affiliation: Department of Cell Biology, UT Southwestern Medical Center, Dallas, TX, USA. Sandra.Schmid@utsouthwestern.edu.
authors.forename: Sandra L
authors.initials: SL
authors.lastname: Schmid
mesh_terms: D018929:Cell Culture Techniques; D002460:Cell Line; D002470:Cell Survival / Q000187:drug effects; D002966:Clathrin / Q000378:metabolism*; D004305:Dose-Response Relationship, Drug; D004705:Endocytosis / Q000187:drug effects* / Q000502:physiology*; D006801:Humans; D007769:Lactams / Q000302:isolation & purification / Q000494:pharmacology*; D046529:Microscopy, Electron, Transmission; D008856:Microscopy, Fluorescence; D021381:Protein Transport
chemical_list: D002966:Clathrin; D007769:Lactams; C074292:ikarugamycin
keywords: IC50; caveolae-mediated endocytosis; clathrin-independent endocytosis; mammalian cells