biostudies-literatureUnknown27(16)Wu JThe actin bundle is an array of linear actin filaments cross-linked by actin-bundling proteins, but its assembly and dynamics are not as well understood as those of the branched actin network. Here we used the Drosophila bristle as a model system to study actin bundle formation. We found that cofilin, a major actin disassembly factor of the branched actin network, promotes the formation and positioning of actin bundles in the developing bristles. Loss of function of cofilin or AIP1, a cofactor of cofilin, each resulted in increased F-actin levels and severe defects in actin bundle organization, with the defects from cofilin deficiency being more severe. Further analyses revealed that cofilin likely regulates actin bundle formation and positioning by the following means. First, cofilin promMolecular biology of the cell2554-64https://www.ebi.ac.uk/biostudies/studies/S-EPMC4985257biostudies-literatureCofilin-mediated actin dynamics promotes actin bundle formation during Drosophila bristle development.PMC4985257Wu JChen JGuo XWang HfalseCofilin-mediated actin dynamics promotes actin bundle formation during Drosophila bristle development.The actin bundle is an array of linear actin filaments cross-linked by actin-bundling proteins, but its assembly and dynamics are not as well understood as those of the branched actin network. Here we used the Drosophila bristle as a model system to study actin bundle formation. We found that cofilin, a major actin disassembly factor of the branched actin network, promotes the formation and positioning of actin bundles in the developing bristles. Loss of function of cofilin or AIP1, a cofactor of cofilin, each resulted in increased F-actin levels and severe defects in actin bundle organization, with the defects from cofilin deficiency being more severe. Further analyses revealed that cofilin likely regulates actin bundle formation and positioning by the following means. First, cofilin prom2016-01-01T00:00:00Z2016 Aug2025-04-25T22:43:26.847Z2019-03-27T02:20:40ZS-EPMC49852572738534510.1091/mbc.E16-02-0084