title: Binding of gelsolin domain 2 to actin. An actin interface distinct from that of gelsolin domain 1 and from ADF/cofilin.
abstract: It is generally assumed that of the six domains that comprise gelsolin, domain 2 is primarily responsible for the initial contact with the actin filament that will ultimately result in the filament being severed. Other actin-binding regions within domains 1 and 4 are involved in gelsolin's severing and subsequent capping activity. The overall fold of all gelsolin repeated domains are similar to the actin depolymerizing factor (ADF)/cofilin family of actin-binding proteins and it has been proposed that there is a similarity in the actin-binding interface. Gelsolin domains 1 and 4 bind G-actin in a similar manner and compete with each other, whereas domain 2 binds F-actin at physiological salt concentrations, and does not compete with domain 1. Here we investigate the domain 2 : actin interface and compare this to our recent studies of the cofilin : actin interface. We conclude that important differences exist between the interfaces of actin with gelsolin domains 1 and 2, and with ADF/cofilin. We present a model for F-actin binding of domain 2 with respect to the F-actin severing and capping activity of the whole gelsolin molecule.
authors.affiliation: UMR 5539 (CNRS) Laboratoire de Motilité Cellulaire (Ecole Pratique des Hautes Etudes), Université de Montpellier, France.
authors.forename: C
authors.initials: C
authors.lastname: Renoult
authors.forename: L
authors.initials: L
authors.lastname: Blondin
authors.forename: A
authors.initials: A
authors.lastname: Fattoum
authors.forename: D
authors.initials: D
authors.lastname: Ternent
authors.forename: S K
authors.initials: SK
authors.lastname: Maciver
authors.forename: F
authors.initials: F
authors.lastname: Raynaud
authors.forename: Y
authors.initials: Y
authors.lastname: Benyamin
authors.forename: C
authors.initials: C
authors.lastname: Roustan
mesh_terms: D051339:Actin Depolymerizing Factors; D000199:Actins / Q000378:metabolism*; D000818:Animals; D001665:Binding Sites; D001667:Binding, Competitive; D003432:Cross-Linking Reagents; D051345:Destrin; D018260:Gelsolin / Q000737:chemistry* / Q000378:metabolism*; D006801:Humans; D066298:In Vitro Techniques; D046911:Macromolecular Substances; D008840:Microfilament Proteins / Q000378:metabolism*; D008958:Models, Molecular; D017510:Protein Folding; D017434:Protein Structure, Tertiary; D011817:Rabbits; D011994:Recombinant Proteins / Q000737:chemistry / Q000378:metabolism; D013050:Spectrometry, Fluorescence; D017550:Spectroscopy, Fourier Transform Infrared
chemical_list: D051339:Actin Depolymerizing Factors; D000199:Actins; D003432:Cross-Linking Reagents; C495824:DSTN protein, human; D051345:Destrin; D018260:Gelsolin; D046911:Macromolecular Substances; D008840:Microfilament Proteins; D011994:Recombinant Proteins