title: Psidin, a conserved protein that regulates protrusion dynamics and cell migration.
abstract: Dynamic assembly and disassembly of actin filaments is a major driving force for cell movements. Border cells in the Drosophila ovary provide a simple and genetically tractable model to study the mechanisms regulating cell migration. To identify new genes that regulate cell movement in vivo, we screened lethal mutations on chromosome 3R for defects in border cell migration and identified two alleles of the gene psidin (psid). In vitro, purified Psid protein bound F-actin and inhibited the interaction of tropomyosin with F-actin. In vivo, psid mutations exhibited genetic interactions with the genes encoding tropomyosin and cofilin. Border cells overexpressing Psid together with GFP-actin exhibited altered protrusion/retraction dynamics. Psid knockdown in cultured S2 cells reduced, and Psid overexpression enhanced, lamellipodial dynamics. Knockdown of the human homolog of Psid reduced the speed and directionality of migration in wounded MCF10A breast epithelial monolayers, whereas overexpression of the protein increased migration speed and altered protrusion dynamics in EGF-stimulated cells. These results indicate that Psid is an actin regulatory protein that plays a conserved role in protrusion dynamics and cell migration.
authors.affiliation: Department of Biological Chemistry, Center for Cell Dynamics, Johns Hopkins School of Medicine, Baltimore, Maryland 21205, USA.
authors.forename: Ji Hoon
authors.initials: JH
authors.lastname: Kim
authors.forename: Aeri
authors.initials: A
authors.lastname: Cho
authors.forename: Hongyan
authors.initials: H
authors.lastname: Yin
authors.forename: Dorothy A
authors.initials: DA
authors.lastname: Schafer
authors.forename: Ghassan
authors.initials: G
authors.lastname: Mouneimne
authors.forename: Kaylene J
authors.initials: KJ
authors.lastname: Simpson
authors.forename: Kim-Vy
authors.initials: KV
authors.lastname: Nguyen
authors.forename: Joan S
authors.initials: JS
authors.lastname: Brugge
authors.forename: Denise J
authors.initials: DJ
authors.lastname: Montell
mesh_terms: D051339:Actin Depolymerizing Factors / Q000378:metabolism; D000818:Animals; D001798:Blood Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D045744:Cell Line, Tumor; D002465:Cell Movement / Q000235:genetics; D022081:Cell Surface Extensions / Q000235:genetics / Q000378:metabolism; D029721:Drosophila Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D004331:Drosophila melanogaster / Q000235:genetics* / Q000378:metabolism*; D005260:Female; D005786:Gene Expression Regulation; D020868:Gene Silencing; D049452:Green Fluorescent Proteins / Q000378:metabolism; D006801:Humans; D009154:Mutation; D010053:Ovary / Q000166:cytology; D014335:Tropomyosin / Q000378:metabolism
chemical_list: D051339:Actin Depolymerizing Factors; D001798:Blood Proteins; D029721:Drosophila Proteins; D014335:Tropomyosin; C485184:enhanced green fluorescent protein; C518075:psidin protein, Drosophila; D049452:Green Fluorescent Proteins