title: Actin Migration Driven by Directional Assembly and Disassembly of Membrane-Anchored Actin Filaments.
abstract: Actin and actin-associated proteins migrate within various cell types. To uncover the mechanism of their migration, we analyzed actin waves, which translocate actin and actin-associated proteins along neuronal axons toward the growth cones. We found that arrays of actin filaments constituting waves undergo directional assembly and disassembly, with their polymerizing ends oriented toward the axonal tip, and that the lateral side of the filaments is mechanically anchored to the adhesive substrate. A combination of live-cell imaging, molecular manipulation, force measurement, and mathematical modeling revealed that wave migration is driven by directional assembly and disassembly of actin filaments and their anchorage to the substrate. Actin-associated proteins co-migrate with actin filaments by interacting with them. Furthermore, blocking this migration, by creating an adhesion-free gap along the axon, disrupts axonal protrusion. Our findings identify a molecular mechanism that translocates actin and associated proteins toward the cell's leading edge, thereby promoting directional cell motility.
authors.affiliation: Laboratory of Systems Neurobiology and Medicine, Graduate School of Biological Sciences, Nara Institute of Science and Technology, Ikoma, Nara 630-0192, Japan.
authors.forename: Hiroko
authors.initials: H
authors.lastname: Katsuno
authors.affiliation: Laboratory of Systems Neurobiology and Medicine, Graduate School of Biological Sciences, Nara Institute of Science and Technology, Ikoma, Nara 630-0192, Japan.
authors.forename: Michinori
authors.initials: M
authors.lastname: Toriyama
authors.affiliation: Green Bio-Nano Laboratory, Graduate School of Materials Science, Nara Institute of Science and Technology, Ikoma, Nara 630-0192, Japan.
authors.forename: Yoichiroh
authors.initials: Y
authors.lastname: Hosokawa
authors.affiliation: Department of Biomolecular Sciences, Graduate School of Life Sciences, Tohoku University, Sendai, Miyagi 980-8578, Japan.
authors.forename: Kensaku
authors.initials: K
authors.lastname: Mizuno
authors.affiliation: Laboratory of Mathematical Informatics, Graduate School of Information Science, Nara Institute of Science and Technology, Ikoma, Nara 630-0192, Japan.
authors.forename: Kazushi
authors.initials: K
authors.lastname: Ikeda
authors.affiliation: Laboratory of Systems Neurobiology and Medicine, Graduate School of Biological Sciences, Nara Institute of Science and Technology, Ikoma, Nara 630-0192, Japan; Biological Systems Design Laboratory, School of Information Science and Technology, Aichi Prefectural University, Nagakute, Aichi 480-1198, Japan.
authors.forename: Yuichi
authors.initials: Y
authors.lastname: Sakumura
authors.affiliation: Laboratory of Systems Neurobiology and Medicine, Graduate School of Biological Sciences, Nara Institute of Science and Technology, Ikoma, Nara 630-0192, Japan. Electronic address: ninagaki@bs.naist.jp.
authors.forename: Naoyuki
authors.initials: N
authors.lastname: Inagaki
mesh_terms: D008841:Actin Cytoskeleton / Q000378:metabolism*; D000199:Actins / Q000378:metabolism*; D000818:Animals; D001370:Axonal Transport; D001369:Axons / Q000378:metabolism; D002478:Cells, Cultured; D055503:Protein Multimerization; D051381:Rats
chemical_list: D000199:Actins