title: The human Ino80 binds to microtubule via the E-hook of tubulin: implications for the role in spindle assembly.
abstract: The human INO80 chromatin remodeling complex, comprising the Ino80 ATPase (hIno80) and the associated proteins such as Tip49a, has been implicated in a variety of nuclear processes other than transcription. We previously have found that hIno80 interacts with tubulin and co-localizes with the mitotic spindle and is required for spindle formation. To better understand the role of hIno80 in spindle formation, we further investigated the interaction between hIno80 and microtubule. Here, we show that the N-terminal domain, dispensable for the nucleosome remodeling activity, is important for hIno80 to interact with tubulin and co-localize with the spindle. The hIno80 N-terminal domain binds to monomeric tubulin and polymerized microtubule in vitro, and the E-hook of tubulin, involved in the polymerization of microtubule, is critical for this binding. Tip49a, which has been reported to associate with the spindle, does not bind to microtubule in vitro and dispensable for spindle formation in vivo. These results suggest that hIno80 can play a direct role in the spindle assembly independent of its chromatin remodeling activity.
authors: Department of Life Science, Division of Life and Pharmaceutical Sciences, Ewha Womans University, Seoul 120-750, Republic of Korea.
authors: Eun-Jung
authors: EJ
authors: Park
authors: Shin-Kyoung
authors: SK
authors: Hur
authors: Han-Sae
authors: HS
authors: Lee
authors: Shin-Ai
authors: SA
authors: Lee
authors: Jongbum
authors: J
authors: Kwon
mesh_terms: D000074183:ATPases Associated with Diverse Cellular Activities; D042002:Chromatin Assembly and Disassembly; D004265:DNA Helicases / Q000235:genetics / Q000378:metabolism*; D004268:DNA-Binding Proteins; D057809:HEK293 Cells; D006801:Humans; D008870:Microtubules / Q000378:metabolism*; D011487:Protein Conformation; D017384:Sequence Deletion; D008941:Spindle Apparatus / Q000378:metabolism*; D014404:Tubulin / Q000737:chemistry / Q000378:metabolism*
chemical_list: D004268:DNA-Binding Proteins; D014404:Tubulin; D000074183:ATPases Associated with Diverse Cellular Activities; D004265:DNA Helicases; C524421:INO80 protein, human