title: Amphidinolide h, a potent cytotoxic macrolide, covalently binds on actin subdomain 4 and stabilizes actin filament.
abstract: 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.
authors.affiliation: Antibiotics Laboratory, RIKEN Discovery Research Institute, 2-1 Hirosawa, Wako-shi, Saitama 351-0198, Japan.
authors.forename: Takeo
authors.initials: T
authors.lastname: Usui
authors.forename: Sayaka
authors.initials: S
authors.lastname: Kazami
authors.forename: Naoshi
authors.initials: N
authors.lastname: Dohmae
authors.forename: Yoshikazu
authors.initials: Y
authors.lastname: Mashimo
authors.forename: Hisae
authors.initials: H
authors.lastname: Kondo
authors.forename: Masashi
authors.initials: M
authors.lastname: Tsuda
authors.forename: Asako Goi
authors.initials: AG
authors.lastname: Terasaki
authors.forename: Kazuyo
authors.initials: K
authors.lastname: Ohashi
authors.forename: Jun'ichi
authors.initials: J
authors.lastname: Kobayashi
authors.forename: Hiroyuki
authors.initials: H
authors.lastname: Osada
mesh_terms: 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
chemical_list: D000199:Actins; D000970:Antineoplastic Agents; D018942:Macrolides; D010446:Peptide Fragments; D014443:Tyrosine; C033025:actin subfragments; C414664:amphidinolide H; D000097442:Amphidinolides