Amphidinolide h, a potent cytotoxic macrolide, covalently binds on actin subdomain 4 and stabilizes actin filament.
The actin-targeting toxins have not only proven to be invaluable tools in studies of actin cytoskeleton structure and function but they also served as a foundation for a new class of anticancer drugs. Here, we describe that amphidinolide H (AmpH) targets actin cytoskeleton. AmpH induced multinucleated cells by disrupting actin organization in the cells, and the hyperpolymerization of purified actin into filaments of apparently normal morphology in vitro. AmpH covalently binds on actin, and the AmpH binding site is determined as Tyr200 of actin subdomain 4 by mass spectrometry and halo assay using the yeast harboring site-directed mutagenized actins. Time-lapse analyses showed that AmpH stimulated the formation of small actin-patches, followed by F-actin rearrangement into aggregates via the retraction of actin fibers. These results indicate that AmpH is a novel actin inhibitor that covalently binds on actin.
Usui
Takeo
T
Antibiotics Laboratory, RIKEN Discovery Research Institute, 2-1 Hirosawa, Wako-shi, Saitama 351-0198, Japan.
Kazami
Sayaka
S
Dohmae
Naoshi
N
Mashimo
Yoshikazu
Y
Kondo
Hisae
H
Tsuda
Masashi
M
Terasaki
Asako Goi
AG
Ohashi
Kazuyo
K
Kobayashi
Jun'ichi
J
Osada
Hiroyuki
H
D008841:Actin Cytoskeleton / Q000378:metabolism*; D000199:Actins / Q000378:metabolism*; D000818:Animals; D000970:Antineoplastic Agents / Q000378:metabolism / Q000494:pharmacology; D001665:Binding Sites; D045744:Cell Line, Tumor; D025141:Drug Resistance, Fungal; D005347:Fibroblasts; D006801:Humans; D018942:Macrolides / Q000378:metabolism* / Q000494:pharmacology*; D008854:Microscopy, Electron; D016297:Mutagenesis, Site-Directed; D010446:Peptide Fragments / Q000378:metabolism*; D051381:Rats; D019032:Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization; D014443:Tyrosine / Q000378:metabolism; D015003:Yeasts / Q000187:drug effects / Q000235:genetics / Q000378:metabolism; D000097442:Amphidinolides
D000199:Actins; D000970:Antineoplastic Agents; D018942:Macrolides; D010446:Peptide Fragments; D014443:Tyrosine; C033025:actin subfragments; C414664:amphidinolide H; D000097442:Amphidinolides