Nebulin as a giant actin-binding template protein in skeletal muscle sarcomere. Interaction of actin and cloned human nebulin fragments.
Nebulin is a family of giant sarcomere matrix proteins of 600-900 kDa in most vertebrate skeletal muscles. Recent sequence analysis suggests that human nebulin is mainly composed of a large number (greater than 200) of conserved repeats of approximately 35 residues. Two cloned nebulin fragments, consisting of 6 and 8 of the repeats, have been expressed in E. coli using the pET3d vector. Both F-actin cosedimentation and solid-phase binding assays demonstrated a specific binding of these nebulin fragments to actin. This finding suggests that nebulin is a giant protein which binds actin at multiple sites in a template-manner. The presence of an actin-binding template protein in the skeletal muscle sarcomere may have significant implications in the assembly and function of the contractile apparatus.
Jin
J P
JP
Department of Chemistry and Biochemistry, University of Texas, Austin 78712.
Wang
K
K
D000199:Actins / Q000378:metabolism*; D003001:Cloning, Molecular; D004926:Escherichia coli / Q000235:genetics; D006801:Humans; D007700:Kinetics; D008970:Molecular Weight; D009124:Muscle Proteins / Q000235:genetics / Q000302:isolation & purification / Q000378:metabolism*; D009132:Muscles / Q000378:metabolism*; D010957:Plasmids; D011485:Protein Binding; D011994:Recombinant Proteins / Q000302:isolation & purification / Q000378:metabolism; D012518:Sarcomeres / Q000378:metabolism*
D000199:Actins; D009124:Muscle Proteins; D011994:Recombinant Proteins; C035620:nebulin