title: Arabidopsis VILLIN4 is involved in root hair growth through regulating actin organization in a Ca2+-dependent manner.
abstract: • Villin is one of the major actin filament bundling proteins in plants. The function of Arabidopsis VILLINs (AtVLNs) is still poorly understood in living cells. In this report, the biochemical activity and cellular function of AtVLN4 were examined. • The biochemical property of AtVLN4 was characterized by co-sedimentation assays, fluorescence microscopy and spectroscopy of pyrene fluorescence. The in vivo function of AtVLN4 was analysed by ectopically expressing it in tobacco pollen and examining the phenotypes of its T-DNA insertional plants. • Recombinant AtVLN4 protein exhibited multiple activities on actin, including actin filament bundling, calcium (Ca(2+))-dependent filament severing and barbed end capping. Expression of AtVLN4 in tobacco pollen induced the formation of supernumerary actin cables and reduced pollen tube growth. Loss of function of AtVLN4 resulted in slowing of root hair growth, alteration in cytoplasmic streaming routes and rate, and reduction of both axial and apical actin bundles. • Our results demonstrated that AtVLN4 is involved in root hair growth through regulating actin organization in a Ca(2+)-dependent manner.
authors.affiliation: Key Laboratory of Cell Proliferation and Regulation Biology of Ministry of Education and College of Life Science, Beijing Normal University, Beijing, China.
authors.forename: Yi
authors.initials: Y
authors.lastname: Zhang
authors.forename: Yingyu
authors.initials: Y
authors.lastname: Xiao
authors.forename: Fei
authors.initials: F
authors.lastname: Du
authors.forename: Lijuan
authors.initials: L
authors.lastname: Cao
authors.forename: Huaijian
authors.initials: H
authors.lastname: Dong
authors.forename: Haiyun
authors.initials: H
authors.lastname: Ren
mesh_terms: D008841:Actin Cytoskeleton / Q000378:metabolism; D000199:Actins / Q000378:metabolism*; D017360:Arabidopsis / Q000235:genetics / Q000254:growth & development* / Q000378:metabolism*; D029681:Arabidopsis Proteins / Q000235:genetics / Q000378:metabolism*; D002118:Calcium / Q000378:metabolism*; D003595:Cytoplasmic Streaming; D004269:DNA, Bacterial / Q000235:genetics; D017343:Genes, Plant / Q000235:genetics; D008840:Microfilament Proteins / Q000235:genetics / Q000378:metabolism*; D016254:Mutagenesis, Insertional / Q000235:genetics; D009154:Mutation / Q000235:genetics; D010641:Phenotype; D018517:Plant Roots / Q000254:growth & development* / Q000378:metabolism; D053205:Pollen Tube / Q000254:growth & development / Q000378:metabolism; D011485:Protein Binding; D021381:Protein Transport; D014026:Nicotiana / Q000254:growth & development / Q000378:metabolism
chemical_list: D000199:Actins; D029681:Arabidopsis Proteins; D004269:DNA, Bacterial; D008840:Microfilament Proteins; C036483:T-DNA; C560263:VLN4 protein, Arabidopsis; D002118:Calcium