Cardiac leiomodin2 binds to the sides of actin filaments and regulates the ATPase activity of myosin
| Autor: | László Grama, Dávid Szatmári, Miklós Nyitrai, Zoltan Ujfalusi, Réka Dudás, Beáta Bugyi |
|---|---|
| Jazyk: | angličtina |
| Rok vydání: | 2017 |
| Předmět: |
0301 basic medicine
Luminescence Muscle Proteins Arp2/3 complex lcsh:Medicine Actin Filaments Microfilament Biochemistry Fluorophotometry Polymerization Myosin head Contractile Proteins Spectrum Analysis Techniques Aromatic Amino Acids Sequence Analysis Protein Myosin Fluorescence Resonance Energy Transfer Amino Acids lcsh:Science Adenosine Triphosphatases Multidisciplinary biology Organic Compounds Chemistry Physics Electromagnetic Radiation Microfilament Proteins Chemical Reactions Tryptophan Actin Cytoskeleton Cell Motility Cell Processes Spectrophotometry Physical Sciences Tropomodulin Research Article Motor Proteins Actin Motors macromolecular substances Myosins Research and Analysis Methods Fluorescence 03 medical and health sciences Molecular Motors Animals Actin Organic Chemistry lcsh:R Chemical Compounds Biology and Life Sciences Proteins Actin remodeling Cell Biology Polymer Chemistry Actin cytoskeleton Actins Protein Structure Tertiary Rats Cytoskeletal Proteins 030104 developmental biology biology.protein Biophysics lcsh:Q Actin Polymerization |
| Zdroj: | PLoS ONE, Vol 12, Iss 10, p e0186288 (2017) PLoS ONE |
| ISSN: | 1932-6203 |
| Popis: | Leiomodin proteins are vertebrate homologues of tropomodulin, having a role in the assembly and maintenance of muscle thin filaments. Leiomodin2 contains an N-terminal tropomodulin homolog fragment including tropomyosin-, and actin-binding sites, and a C-terminal Wiskott-Aldrich syndrome homology 2 actin-binding domain. The cardiac leiomodin2 isoform associates to the pointed end of actin filaments, where it supports the lengthening of thin filaments and competes with tropomodulin. It was recently found that cardiac leiomodin2 can localise also along the length of sarcomeric actin filaments. While the activities of leiomodin2 related to pointed end binding are relatively well described, the potential side binding activity and its functional consequences are less well understood. To better understand the biological functions of leiomodin2, in the present work we analysed the structural features and the activities of Rattus norvegicus cardiac leiomodin2 in actin dynamics by spectroscopic and high-speed sedimentation approaches. By monitoring the fluorescence parameters of leiomodin2 tryptophan residues we found that it possesses flexible, intrinsically disordered regions. Leiomodin2 accelerates the polymerisation of actin in an ionic strength dependent manner, which relies on its N-terminal regions. Importantly, we demonstrate that leiomodin2 binds to the sides of actin filaments and induces structural alterations in actin filaments. Upon its interaction with the filaments leiomodin2 decreases the actin-activated Mg2+-ATPase activity of skeletal muscle myosin. These observations suggest that through its binding to side of actin filaments and its effect on myosin activity leiomodin2 has more functions in muscle cells than it was indicated in previous studies. |
| Databáze: | OpenAIRE |
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