Open AccessCofilin is a component of intranuclear and cytoplasmic actin rods induced in cultured cells.
Author(s) -
Eisuke Nishida,
Kei Iida,
Naoto Yonezawa,
Shigeo Koyasu,
Ichiro Yahara,
Hikoichi Sakai
Publication year - 1987
Publication title -
proceedings of the national academy of sciences of the united states of america
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 5.011
H-Index - 771
eISSN - 1091-6490
pISSN - 0027-8424
DOI - 10.1073/pnas.84.15.5262
Subject(s) - cofilin , phalloidin , actin remodeling of neurons , actin remodeling , actin , actin binding protein , cytoplasm , microbiology and biotechnology , mdia1 , actina , biophysics , microfilament , biology , chemistry , actin cytoskeleton , cytoskeleton , biochemistry , cell
Incubation of cultured cells under specific conditions induces a dramatic change in the actin organization: induction of intranuclear and/or cytoplasmic actin rods (actin paracrystal-like intracellular structures). We have found that cofilin, a 21-kDa actin-binding protein, is a component of these rods. Antibodies directed against cofilin labeled intranuclear actin rods induced in cells treated with dimethyl sulfoxide or exposed to heat shock and also labeled cytoplasmic actin rods induced in cells incubated in specific salt buffers. Moreover, we found that these actin rods are not stained with fluorescent phalloidin derivatives at all and appear to be right-handed helices, different from straight bundles of F-actin such as stress fibers. In vitro experiments revealed that cofilin and phalloidin compete with each other for binding to F-actin. Since cofilin and phalloidin have the ability to stoichiometrically bind actin molecule in the filament in vitro, the above results seem to suggest that cofilin directly binds to actin molecule in nearly an equimolar ratio in these rods. We call these rods "actin/cofilin rods."