Leiomodin/tropomyosin interactions are isoform specific.
Leiomodins are larger homologs of tropomodulin, a tropomyosin-binding, actin-capping protein. There are several leiomodin isoforms, one of them found in smooth muscles (Lmod1) and another one found in cardiac and skeletal muscles (Lmod2). In this work, the tropomyosin-binding abilities of these two isoforms were studied. The tropomyosin-binding sites were localized in the N-terminal regions of Lmod1 and Lmod2. The affinities of the leiomodin fragments containing the tropomyosin-binding sites for tropomyosin peptides containing N-termini of different tropomyosin isoforms, alpha, gamma and delta, were determined and compared using non-denaturing gel-electrophoresis and circular dichroism. It was shown that leiomodin/tropomyosin binding is isoform-specific and differs almost 100-fold for different tropomyosin isoforms.
Kostyukova
Alla S
AS
Department of Neuroscience and Cell Biology, Robert Wood Johnson Medical School, 675 Hoes Lane, Piscataway, NJ 08854, USA. kostyuas@umdnj.edu
D000595:Amino Acid Sequence; D001665:Binding Sites; D003598:Cytoskeletal Proteins / Q000737:chemistry*; D008969:Molecular Sequence Data; D009124:Muscle Proteins / Q000737:chemistry*; D011485:Protein Binding; D025941:Protein Interaction Mapping; D051348:Tropomodulin / Q000737:chemistry*; D014335:Tropomyosin / Q000737:chemistry*
D003598:Cytoskeletal Proteins; D009124:Muscle Proteins; D051348:Tropomodulin; D014335:Tropomyosin; C523689:leiomodin protein, mouse