The tumor inhibitor and antiangiogenic agent withaferin A targets the intermediate filament protein vimentin.
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.
Bargagna-Mohan
Paola
P
Department of Ophthalmology and Visual Sciences, University of Kentucky, Lexington, KY 40536, USA.
Hamza
Adel
A
Kim
Yang-eon
YE
Khuan Abby Ho
Yik
Y
Mor-Vaknin
Nirit
N
Wendschlag
Nicole
N
Liu
Junjun
J
Evans
Robert M
RM
Markovitz
David M
DM
Zhan
Chang-Guo
CG
Kim
Kyung Bo
KB
Mohan
Royce
R
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
D020533:Angiogenesis Inhibitors; D000970:Antineoplastic Agents; D014746:Vimentin; D054358:Withanolides; C009684:withaferin A; D004875:Ergosterol