title: The tumor inhibitor and antiangiogenic agent withaferin A targets the intermediate filament protein vimentin.
abstract: The natural product withaferin A (WFA) exhibits antitumor and antiangiogenesis activity in vivo, which results from this drug's potent growth inhibitory activities. Here, we show that WFA binds to the intermediate filament (IF) protein, vimentin, by covalently modifying its cysteine residue, which is present in the highly conserved alpha-helical coiled coil 2B domain. WFA induces vimentin filaments to aggregate in vitro, an activity manifested in vivo as punctate cytoplasmic aggregates that colocalize vimentin and F-actin. WFA's potent dominant-negative effect on F-actin requires vimentin expression and induces apoptosis. Finally, we show that WFA-induced inhibition of capillary growth in a mouse model of corneal neovascularization is compromised in vimentin-deficient mice. These findings identify WFA as a chemical genetic probe of IF functions, and illuminate a potential molecular target for withanolide-based therapeutics for treating angioproliferative and malignant diseases.
authors.affiliation: Department of Ophthalmology and Visual Sciences, University of Kentucky, Lexington, KY 40536, USA.
authors.forename: Paola
authors.initials: P
authors.lastname: Bargagna-Mohan
authors.forename: Adel
authors.initials: A
authors.lastname: Hamza
authors.forename: Yang-eon
authors.initials: YE
authors.lastname: Kim
authors.forename: Yik
authors.initials: Y
authors.lastname: Khuan Abby Ho
authors.forename: Nirit
authors.initials: N
authors.lastname: Mor-Vaknin
authors.forename: Nicole
authors.initials: N
authors.lastname: Wendschlag
authors.forename: Junjun
authors.initials: J
authors.lastname: Liu
authors.forename: Robert M
authors.initials: RM
authors.lastname: Evans
authors.forename: David M
authors.initials: DM
authors.lastname: Markovitz
authors.forename: Chang-Guo
authors.initials: CG
authors.lastname: Zhan
authors.forename: Kyung Bo
authors.initials: KB
authors.lastname: Kim
authors.forename: Royce
authors.initials: R
authors.lastname: Mohan
mesh_terms: D020533:Angiogenesis Inhibitors / Q000737:chemistry / Q000494:pharmacology / Q000627:therapeutic use; D000818:Animals; D000970:Antineoplastic Agents / Q000737:chemistry / Q000494:pharmacology* / Q000627:therapeutic use; D017209:Apoptosis / Q000187:drug effects; D001665:Binding Sites; D015153:Blotting, Western; D002460:Cell Line; D016510:Corneal Neovascularization / Q000188:drug therapy; D015180:Electrophoresis, Gel, Two-Dimensional; D004875:Ergosterol / Q000031:analogs & derivatives* / Q000737:chemistry / Q000494:pharmacology / Q000627:therapeutic use; D005347:Fibroblasts / Q000187:drug effects / Q000378:metabolism; D005434:Flow Cytometry; D006801:Humans; D051379:Mice; D018345:Mice, Knockout; D008958:Models, Molecular; D015394:Molecular Structure; D011485:Protein Binding; D014746:Vimentin / Q000235:genetics / Q000378:metabolism*; D054358:Withanolides
chemical_list: D020533:Angiogenesis Inhibitors; D000970:Antineoplastic Agents; D014746:Vimentin; D054358:Withanolides; C009684:withaferin A; D004875:Ergosterol