title: Spontaneous structural changes in actin regulate G-F transformation.
abstract: Transformations between G- (monomeric) and F-actin (polymeric) are important in cellular behaviors such as migration, cytokinesis, and morphing. In order to understand these transitions, we combined single-molecule Förster resonance energy transfer with total internal reflection fluorescence microscopy to examine conformational changes of individual actin protomers. We found that the protomers can take different conformational states and that the transition interval is in the range of hundreds of seconds. The distribution of these states was dependent on the environment, suggesting that actin undergoes spontaneous structural changes that accommodate itself to polymerization.
authors.affiliation: Nanobiology Laboratories, Graduate School of Frontier Biosciences, Osaka University, Suita, Osaka, Japan.
authors.forename: Masatoshi
authors.initials: M
authors.lastname: Morimatsu
authors.forename: Yuichi
authors.initials: Y
authors.lastname: Togashi
authors.forename: So
authors.initials: S
authors.lastname: Nishikawa
authors.forename: Mitsuhiro
authors.initials: M
authors.lastname: Sugawa
authors.forename: Atsuko H
authors.initials: AH
authors.lastname: Iwane
authors.forename: Toshio
authors.initials: T
authors.lastname: Yanagida
mesh_terms: D000199:Actins / Q000737:chemistry*; D000818:Animals; D031541:Fluorescence Resonance Energy Transfer; D008856:Microscopy, Fluorescence; D008958:Models, Molecular; D058105:Polymerization; D011487:Protein Conformation; D051381:Rats
chemical_list: D000199:Actins