Molecular dissection of the interaction of desmin with the C-terminal region of nebulin.
In vertebrate skeletal muscle, ultrastructural studies have suggested that the Z-line and extracellular intermediate filaments are linked, although a structural basis for this has remained elusive. We searched for potential novel ligands of the Z-line portion of nebulin by a yeast two-hybrid (Y2H) approach. This identified that the nebulin modules M160 to M170 interact with desmin. In desmin, deletion series experiments assigned a 19-kDa central coiled-coil domain as the nebulin-binding site. The specific interactions of nebulin and desmin were confirmed in vitro by GST pull-down experiments. In situ, the nebulin modules M176 to M181 colocalize with desmin in a Z-line-associated, striated pattern as shown by immunofluorescence studies. Our data are consistent with a model that desmin attaches directly to the Z-line through its interaction with the nebulin repeats M163-M170. This interaction may link myofibrillar Z-discs to the intermediate filament system, thereby forming a lateral linkage system which contributes to maintain adjacent Z-lines in register.
Bang
Marie-Louise
ML
Department of Anesthesiology and Intensive Operative Care, Universitätsklinikum Mannheim, Mannheim, Germany.
Gregorio
Carol
C
Labeit
Siegfried
S
D000818:Animals; D003893:Desmin / Q000737:chemistry*; D019084:Fluorescent Antibody Technique, Indirect; D005982:Glutathione Transferase / Q000378:metabolism; D006801:Humans; D009124:Muscle Proteins / Q000737:chemistry*; D018482:Muscle, Skeletal / Q000378:metabolism; D011485:Protein Binding; D014176:Protein Biosynthesis; D017434:Protein Structure, Tertiary; D011817:Rabbits; D014158:Transcription, Genetic; D020798:Two-Hybrid System Techniques
D003893:Desmin; D009124:Muscle Proteins; C035620:nebulin; D005982:Glutathione Transferase