title: Drebrin-like protein DBN-1 is a sarcomere component that stabilizes actin filaments during muscle contraction.
abstract: Actin filament organization and stability in the sarcomeres of muscle cells are critical for force generation. Here we identify and functionally characterize a Caenorhabditis elegans drebrin-like protein DBN-1 as a novel constituent of the muscle contraction machinery. In vitro, DBN-1 exhibits actin filament binding and bundling activity. In vivo, DBN-1 is expressed in body wall muscles of C. elegans. During the muscle contraction cycle, DBN-1 alternates location between myosin- and actin-rich regions of the sarcomere. In contracted muscle, DBN-1 is accumulated at I-bands where it likely regulates proper spacing of α-actinin and tropomyosin and protects actin filaments from the interaction with ADF/cofilin. DBN-1 loss of function results in the partial depolymerization of F-actin during muscle contraction. Taken together, our data show that DBN-1 organizes the muscle contractile apparatus maintaining the spatial relationship between actin-binding proteins such as α-actinin, tropomyosin and ADF/cofilin and possibly strengthening actin filaments by bundling.
authors.affiliation: Drittes Physikalisches Institut, Georg-August-Universität, Friedrich-Hund-Platz 1, 37077 Göttingen, Germany.
authors.forename: Eugenia
authors.initials: E
authors.lastname: Butkevich
authors.affiliation: Drittes Physikalisches Institut, Georg-August-Universität, Friedrich-Hund-Platz 1, 37077 Göttingen, Germany.
authors.forename: Kai
authors.initials: K
authors.lastname: Bodensiek
authors.affiliation: Drittes Physikalisches Institut, Georg-August-Universität, Friedrich-Hund-Platz 1, 37077 Göttingen, Germany.
authors.forename: Nikta
authors.identifier: http://orcid.org/0000-0003-1261-7465
authors.initials: N
authors.lastname: Fakhri
authors.affiliation: Drittes Physikalisches Institut, Georg-August-Universität, Friedrich-Hund-Platz 1, 37077 Göttingen, Germany.
authors.forename: Kerstin
authors.initials: K
authors.lastname: von Roden
authors.affiliation: Drittes Physikalisches Institut, Georg-August-Universität, Friedrich-Hund-Platz 1, 37077 Göttingen, Germany.|Center for Nanoscale Microscopy and Molecular Physiology of the Brain (CNMPB), 37073 Göttingen, Germany.
authors.forename: Iwan A T
authors.identifier: http://orcid.org/0000-0001-6665-5104
authors.initials: IAT
authors.lastname: Schaap
authors.affiliation: Institute of Biology, Center for Structural and Cell Biology in Medicine, University of Lübeck, 23538 Lübeck, Germany.
authors.forename: Irina
authors.initials: I
authors.lastname: Majoul
authors.affiliation: Drittes Physikalisches Institut, Georg-August-Universität, Friedrich-Hund-Platz 1, 37077 Göttingen, Germany.
authors.forename: Christoph F
authors.initials: CF
authors.lastname: Schmidt
authors.affiliation: Drittes Physikalisches Institut, Georg-August-Universität, Friedrich-Hund-Platz 1, 37077 Göttingen, Germany.
authors.forename: Dieter R
authors.initials: DR
authors.lastname: Klopfenstein
mesh_terms: D008841:Actin Cytoskeleton / Q000502:physiology*; D000818:Animals; D019556:COS Cells; D017173:Caenorhabditis elegans / Q000235:genetics / Q000378:metabolism*; D029742:Caenorhabditis elegans Proteins / Q000235:genetics / Q000378:metabolism; D002522:Chlorocebus aethiops; D005786:Gene Expression Regulation / Q000502:physiology; D008856:Microscopy, Fluorescence; D009119:Muscle Contraction / Q000502:physiology*; D018482:Muscle, Skeletal / Q000502:physiology*; D009479:Neuropeptides / Q000235:genetics / Q000378:metabolism*; D011401:Promoter Regions, Genetic; D012518:Sarcomeres / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*
chemical_list: D029742:Caenorhabditis elegans Proteins; D009479:Neuropeptides; C053386:drebrins