@article{oai:tsukuba.repo.nii.ac.jp:00043460, author = {中野, 賢太郎 and 沼田, 治 and Morita, Rikuri and Takaine, Masak and Numata, Osamu and Nakano, Kentaro}, issue = {2}, journal = {The journal of biochemistry}, month = {Aug}, note = {A contractile ring (CR) is involved in cytokinesis in animal and yeast cells. Although several types of actin-bundling proteins associate with F-actin in the CR, their individual roles in the CR have not yet been elucidated in detail. Ain1 is the sole α-actinin homologue in the fission yeast Schizosaccharomyces pombe and specifically localizes to the CR with a high turnover rate. S. pombe cells lacking the ain1+ gene show defects in cytokinesis under stress conditions. We herein investigated the biochemical activity and cellular localization mechanisms of Ain1. Ain1 showed weaker affinity to F-actin in vitro than other actin-bundling proteins in S. pombe. We identified a mutation that presumably loosened the interaction between two calponin-homology domains constituting the single actin-binding domain (ABD) of Ain1, which strengthened the actin-binding activity of Ain1. This mutant protein induced a deformation in the ring shape of the CR. Neither a truncated protein consisting only of an N-terminal ABD nor a truncated protein lacking a C-terminal region containing an EF-hand motif localized to the CR, whereas the latter was involved in the bundling of F-actin in vitro. We herein propose detailed mechanisms for how each part of the molecule is involved in the proper cellular localization and function of Ain1.}, pages = {93--102}, title = {Molecular dissection of the actin-binding ability of the fission yeast α-actinin, Ain1, in vitro and in vivo}, volume = {162}, year = {2017} }