Connectin/titin, giant elastic protein of muscle.
The structure and function of the giant elastic protein connectin/titin are described on the basis of recent investigations. The 3000 kDa protein links the Z line to the myosin filament in striated muscle sarcomeres. The NH2-terminal region of connectin filament is involved in the Z line binding, and the COOH-terminal region is bound onto the myosin filament with an overlap between the counter-connectin filaments at the M line. The PEVK region in the I band is shown to be mainly responsible for passive tension generation. The longitudinal continuity of myosin-, actin-free sarcomeres is explained by the linkage of freed connectin filaments extending from both sides of the Z lines in a sarcomere. The role of connectin in myofibrillar differentiation and the biodiversity of connectin-related proteins in the animal kingdom are briefly reviewed.
Maruyama
K
K
Office of the President, Chiba University, Japan.
D000818:Animals; D064211:Connectin; D004548:Elasticity; D006801:Humans; D005810:Multigene Family; D009124:Muscle Proteins / Q000502:physiology*; D018482:Muscle, Skeletal / Q000648:ultrastructure; D009132:Muscles / Q000648:ultrastructure*; D009206:Myocardium / Q000648:ultrastructure; D009210:Myofibrils / Q000648:ultrastructure; D009218:Myosins / Q000378:metabolism; D011485:Protein Binding; D011494:Protein Kinases / Q000502:physiology*
D064211:Connectin; D009124:Muscle Proteins; C577285:TTN protein, human; D011494:Protein Kinases; D009218:Myosins