title: Usual and unusual biochemical properties of ADF/cofilin-like protein Adf73p in ciliate Tetrahymena thermophila.
abstract: Actin-depolymerizing factor (ADF)/cofilin is a well-conserved actin-modulating protein, which induces reorganization of the actin cytoskeleton by severing and depolymerizing F-actin. ADF/cofilin also binds to G-actin and inhibits nucleotide exchange, and hence, is supposed to regulate the nucleotide-bound state of the cellular G-actin pool cooperating with profilin, another well-conserved G-actin-binding protein that promotes nucleotide exchange. In this report, we investigated the biochemical properties of the ADF/cofilin-like protein Adf73p from ciliate Tetrahymena thermophila. Adf73p also binds to both G- and F-actin and severs and depolymerizes F-actin. Unlike canonical ADF/cofilin, however, Adf73p accelerates nucleotide exchange on actin and allows repolymerization of disassembled actin. These results suggest that the actin cytoskeleton of T. thermophila is regulated by Adf73p in a different way from those of mammals, plants, and yeasts.
authors.affiliation: Structural Biosciences, Graduate School of Life and Environmental Sciences, University of Tsukuba, Tsukuba, Ibaraki 305-8572, Japan.
authors.forename: Nanami
authors.initials: N
authors.lastname: Shiozaki
authors.forename: Kentaro
authors.initials: K
authors.lastname: Nakano
authors.forename: Masak
authors.initials: M
authors.lastname: Takaine
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Abe
authors.forename: Osamu
authors.initials: O
authors.lastname: Numata
mesh_terms: D051339:Actin Depolymerizing Factors / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D000199:Actins / Q000378:metabolism; D000818:Animals; D015800:Protozoan Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D016808:Tetrahymena thermophila / Q000235:genetics / Q000378:metabolism*
chemical_list: D051339:Actin Depolymerizing Factors; D000199:Actins; D015800:Protozoan Proteins