title: Phalloidin perturbs the interaction of human non-muscle myosin isoforms 2A and 2C1 with F-actin.
abstract: Phalloidin and fluorescently labeled phalloidin analogs are established reagents to stabilize and mark actin filaments for the investigation of acto-myosin interactions. In the present study, we employed transient and steady-state kinetic measurements as well as in vitro motility assays to show that phalloidin perturbs the productive interaction of human non-muscle myosin-2A and -2C1 with filamentous actin. Phalloidin binding to F-actin results in faster dissociation of the complex formed with non-muscle myosin-2A and -2C1, reduced actin-activated ATP turnover, and slower velocity of actin filaments in the in vitro motility assay. In contrast, phalloidin binding to F-actin does not affect the interaction with human non-muscle myosin isoform 2B and Dictyostelium myosin-2 and myosin-5b.
authors.affiliation: Institute for Biophysical Chemistry, Hannover Medical School, Germany.
authors.forename: Ralph P
authors.initials: RP
authors.lastname: Diensthuber
authors.forename: Mirco
authors.initials: M
authors.lastname: Müller
authors.forename: Sarah M
authors.initials: SM
authors.lastname: Heissler
authors.forename: Manuel H
authors.initials: MH
authors.lastname: Taft
authors.forename: Igor
authors.initials: I
authors.lastname: Chizhov
authors.forename: Dietmar J
authors.initials: DJ
authors.lastname: Manstein
mesh_terms: D008841:Actin Cytoskeleton / Q000187:drug effects / Q000378:metabolism; D000199:Actins / Q000378:metabolism*; D004023:Dictyostelium / Q000378:metabolism; D006801:Humans; D007700:Kinetics; D018995:Myosin Heavy Chains / Q000378:metabolism*; D024462:Myosin Type II / Q000378:metabolism*; D024507:Nonmuscle Myosin Type IIA / Q000378:metabolism*; D010590:Phalloidine / Q000494:pharmacology*; D010782:Photolysis / Q000187:drug effects; D011485:Protein Binding / Q000187:drug effects; D020033:Protein Isoforms / Q000378:metabolism
chemical_list: D000199:Actins; D018995:Myosin Heavy Chains; D024462:Myosin Type II; D024507:Nonmuscle Myosin Type IIA; D010590:Phalloidine; D020033:Protein Isoforms; C477830:MYH7b protein, human