ノズミ　モトヒロ   野住　素広    所属   新潟薬科大学  医療技術学部 臨床検査学科    職種   教授
発行・発表の年月	2024/07
形態種別	論文 - 研究論文（学術雑誌）
査読	査読あり
標題	Identification of z‐axis filopodia in growth cones using super‐resolution microscopy
執筆形態	その他 - 指定なし
掲載誌名	Journal of Neurochemistry
出版社・発行元	Wiley
担当区分	筆頭著者
著者・共著者	Motohiro Nozumi,Yuta Sato,Miyako Nishiyama‐Usuda,Michihiro Igarashi
概要	Abstract A growth cone is a highly motile tip of an extending axon that is crucial for neural network formation. Three‐dimensional‐structured illumination microscopy, a type of super‐resolution light microscopy with a resolution that overcomes the optical diffraction limitation (ca. 200 nm) of conventional light microscopy, is well suited for studying the molecular dynamics of intracellular events. Using this technique, we discovered a novel type of filopodia distributed along the z‐axis (“z‐filopodia”) within the growth cone. Z‐filopodia were typically oriented in the direction of axon growth, not attached to the substratum, protruded spontaneously without microtubule invasion, and had a lifetime that was considerably shorter than that of conventional filopodia. Z‐filopodia formation and dynamics were regulated by actin‐regulatory proteins, such as vasodilator‐stimulated phosphoprotein, fascin, and cofilin. Chromophore‐assisted laser inactivation of cofilin induced the rapid turnover of z‐filopodia. An axon guidance receptor, neuropilin‐1, was concentrated in z‐filopodia and was transported together with them, whereas its ligand, semaphorin‐3A, was selectively bound to them. Membrane domains associated with z‐filopodia were also specialized and resembled those of lipid rafts, and their behaviors were closely related to those of neuropilin‐1. The results suggest that z‐filopodia have unique turnover properties, and unlike xy‐filopodia, do not function as force‐generating structures for axon extension.image
DOI	10.1111/jnc.16162
ISSN	0022-3042/1471-4159
PermalinkURL	https://onlinelibrary.wiley.com/doi/pdf/10.1111/jnc.16162