title: Congenital macrothrombocytopenia-linked mutations in the actin-binding domain of α-actinin-1 enhance F-actin association.
abstract: Mutations in the actin cross-linking protein actinin-1 were recently linked to dominantly inherited congenital macrothrombocytopenia. Here, we report that several disease-associated mutations that are located within the actinin-1 actin-binding domain cause increased binding of actinin-1 to actin filaments and enhance filament bundling in vitro. These actinin-1 mutants are also more stably associated with the cytoskeleton in cultured cells, as assessed by biochemical fractionation and fluorescence recovery after photobleaching experiments. For two mutations the disruption of contacts between the calponin homology domains within the actinin actin-binding domain may explain increased filament binding--providing mechanistic and structural insights into the basis of actinin-1 dysfunction in congenital macrothrombocytopenia.
authors.affiliation: School of Biochemistry and Cell Biology, University College Cork, Ireland.
authors.forename: Anita C H
authors.initials: AC
authors.lastname: Murphy
authors.affiliation: Molecular Cell Biology Laboratory, School of Biochemistry and Cell Biology, Biosciences Institute, University College Cork, Ireland.
authors.forename: Andrew J
authors.initials: AJ
authors.lastname: Lindsay
authors.affiliation: Molecular Cell Biology Laboratory, School of Biochemistry and Cell Biology, Biosciences Institute, University College Cork, Ireland.
authors.forename: Mary W
authors.initials: MW
authors.lastname: McCaffrey
authors.affiliation: Department of Structural and Computational Biology, Max F. Perutz Laboratories, University of Vienna, Austria.|Department of Biochemistry, Faculty of Chemistry and Chemical Technology, University of Ljubljana, Slovenia.
authors.forename: Kristina
authors.initials: K
authors.lastname: Djinović-Carugo
authors.affiliation: School of Biochemistry and Cell Biology, University College Cork, Ireland.
authors.forename: Paul W
authors.initials: PW
authors.lastname: Young
mesh_terms: D008841:Actin Cytoskeleton / Q000737:chemistry / Q000378:metabolism; D000185:Actinin / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism*; D000199:Actins / Q000378:metabolism*; D000595:Amino Acid Sequence; D019943:Amino Acid Substitution; D001665:Binding Sites / Q000235:genetics; D036681:Fluorescence Recovery After Photobleaching; D006367:HeLa Cells; D006801:Humans; D066298:In Vitro Techniques; D008958:Models, Molecular; D008969:Molecular Sequence Data; D050505:Mutant Proteins / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism*; D020125:Mutation, Missense; D011485:Protein Binding; D011487:Protein Conformation; D054730:Protein Interaction Domains and Motifs; D011994:Recombinant Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D013921:Thrombocytopenia / Q000151:congenital* / Q000235:genetics* / Q000378:metabolism
chemical_list: C526905:ACTN1 protein, human; D000199:Actins; D050505:Mutant Proteins; D011994:Recombinant Proteins; D000185:Actinin
keywords: ACTN1; actin; actinin-1; alpha-actinin; congenital macrothrombocytopenia; macrothrombocytopenia; α-actinin