title: Structural and Biochemical Basis for the Inhibitory Effect of Liprin-α3 on Mouse Diaphanous 1 (mDia1) Function.
abstract: Diaphanous-related formins are eukaryotic actin nucleation factors regulated by an autoinhibitory interaction between the N-terminal RhoGTPase-binding domain (mDiaN) and the C-terminal Diaphanous-autoregulatory domain (DAD). Although the activation of formins by Rho proteins is well characterized, its inactivation is only marginally understood. Recently, liprin-α3 was shown to interact with mDia1. Overexpression of liprin-α3 resulted in a reduction of the cellular actin filament content. The molecular mechanisms of how liprin-α3 exerts this effect and counteracts mDia1 activation by RhoA are unknown. Here, we functionally and structurally define a minimal liprin-α3 core region, sufficient to recapitulate the liprin-α3 determined mDia1-respective cellular functions. We show that liprin-α3 alters the interaction kinetics and thermodynamics of mDiaN with RhoA·GTP and DAD. RhoA displaces liprin-α3 allosterically, whereas DAD competes with liprin-α3 for a highly overlapping binding site on mDiaN. Liprin-α3 regulates actin polymerization by lowering the regulatory potency of RhoA and DAD on mDiaN. We present a model of a mechanistically unexplored and new aspect of mDiaN regulation by liprin-α3.
authors.affiliation: From the Institute for Genetics and Cologne Excellence Cluster on Cellular Stress Responses in Aging-associated Diseases (CECAD), Joseph-Stelzmann-Strasse 26, University of Cologne, 50931 Cologne, Germany and.
authors.forename: Julian
authors.initials: J
authors.lastname: Brenig
authors.affiliation: From the Institute for Genetics and Cologne Excellence Cluster on Cellular Stress Responses in Aging-associated Diseases (CECAD), Joseph-Stelzmann-Strasse 26, University of Cologne, 50931 Cologne, Germany and.
authors.forename: Susanne
authors.initials: S
authors.lastname: de Boor
authors.affiliation: From the Institute for Genetics and Cologne Excellence Cluster on Cellular Stress Responses in Aging-associated Diseases (CECAD), Joseph-Stelzmann-Strasse 26, University of Cologne, 50931 Cologne, Germany and.
authors.forename: Philipp
authors.initials: P
authors.lastname: Knyphausen
authors.affiliation: From the Institute for Genetics and Cologne Excellence Cluster on Cellular Stress Responses in Aging-associated Diseases (CECAD), Joseph-Stelzmann-Strasse 26, University of Cologne, 50931 Cologne, Germany and.
authors.forename: Nora
authors.initials: N
authors.lastname: Kuhlmann
authors.affiliation: From the Institute for Genetics and Cologne Excellence Cluster on Cellular Stress Responses in Aging-associated Diseases (CECAD), Joseph-Stelzmann-Strasse 26, University of Cologne, 50931 Cologne, Germany and.
authors.forename: Sarah
authors.initials: S
authors.lastname: Wroblowski
authors.affiliation: From the Institute for Genetics and Cologne Excellence Cluster on Cellular Stress Responses in Aging-associated Diseases (CECAD), Joseph-Stelzmann-Strasse 26, University of Cologne, 50931 Cologne, Germany and.
authors.forename: Linda
authors.initials: L
authors.lastname: Baldus
authors.affiliation: From the Institute for Genetics and Cologne Excellence Cluster on Cellular Stress Responses in Aging-associated Diseases (CECAD), Joseph-Stelzmann-Strasse 26, University of Cologne, 50931 Cologne, Germany and.
authors.forename: Lukas
authors.initials: L
authors.lastname: Scislowski
authors.affiliation: From the Institute for Genetics and Cologne Excellence Cluster on Cellular Stress Responses in Aging-associated Diseases (CECAD), Joseph-Stelzmann-Strasse 26, University of Cologne, 50931 Cologne, Germany and.
authors.forename: Oliver
authors.initials: O
authors.lastname: Artz
authors.affiliation: From the Institute for Genetics and Cologne Excellence Cluster on Cellular Stress Responses in Aging-associated Diseases (CECAD), Joseph-Stelzmann-Strasse 26, University of Cologne, 50931 Cologne, Germany and.
authors.forename: Philip
authors.initials: P
authors.lastname: Trauschies
authors.affiliation: the Institute for Biochemistry, University of Cologne, Zülpicher Strasse 47, 50674 Cologne, Germany.
authors.forename: Ulrich
authors.initials: U
authors.lastname: Baumann
authors.affiliation: the Institute for Biochemistry, University of Cologne, Zülpicher Strasse 47, 50674 Cologne, Germany.
authors.forename: Ines
authors.initials: I
authors.lastname: Neundorf
authors.affiliation: From the Institute for Genetics and Cologne Excellence Cluster on Cellular Stress Responses in Aging-associated Diseases (CECAD), Joseph-Stelzmann-Strasse 26, University of Cologne, 50931 Cologne, Germany and michael.lammers@uni-koeln.de.
authors.forename: Michael
authors.initials: M
authors.lastname: Lammers
mesh_terms: D000199:Actins / Q000378:metabolism; D000595:Amino Acid Sequence; D000818:Animals; D001665:Binding Sites; D002352:Carrier Proteins / Q000737:chemistry / Q000378:metabolism*; D018360:Crystallography, X-Ray; D000080865:Formins; D006367:HeLa Cells; D006801:Humans; D051379:Mice; D008958:Models, Molecular; D008969:Molecular Sequence Data; D017433:Protein Structure, Secondary; D033921:Vesicular Transport Proteins / Q000737:chemistry / Q000378:metabolism*; D020742:rhoA GTP-Binding Protein / Q000378:metabolism
chemical_list: D000199:Actins; D002352:Carrier Proteins; C491464:Diap1 protein, mouse; D000080865:Formins; D033921:Vesicular Transport Proteins; C000593216:liprin alpha3 protein, mouse; D020742:rhoA GTP-Binding Protein
keywords: Ras homolog gene family, member A (RhoA); actin; cytoskeleton; formin; liprin; mDia1