What does titin do in muscle?

Titin has long been recognized as a mechanical protein in muscle cells that has a main function as a molecular spring in the contractile units, the sarcomeres. Recent work suggests that the titin spring contributes to muscle contraction in a more active manner than previously thought.

What kind of protein is titin?

giant structural sarcomeric protein
Titin is a giant structural sarcomeric protein with a molecular weight of more than 3800 kD. The largest human protein, it forms the third filament system in striated muscle along with actin and myosin. Single titin molecules span half sarcomeres from Z disks to M lines in skeletal and cardiac muscle.

What is the longest human protein?

Titin
Titin, is definitely the largest protein in the body, with a molecular weight of 3 million Dalton and composed of 27,000 amino acids. Paradoxically, this huge structure was elusive until the last decade but, since it was described in muscle tissue, its importance has rapidly emerged.

What is titin myopathy?

Titin abnormalities can cause a wide spectrum of muscle disorders called “Titinopathy”. These disorders may be also called a “myopathy” or a “dystrophy” including limb-girdle muscular dystrophy (LGMD) and tibial muscular dystrophy.

Is titin attached to myosin?

Together with the relatively rigid association of titin with myosin, this titin link to actin results in a passive molecular spring that is arranged in parallel with attached cross-bridges, while it is in series with the myosin filament and the actin filament near its insertion into the Z-band in the relaxed muscle.

What is titin in physiology?

Titin is a giant protein of vertebrate striated muscles (M(r), > or = 3000 kD). Its molecules are of filamentous shape and span from the Z disk to the M line, thereby forming a third filament system of the sarcomere.

What is titin attached to?

Titin is the largest protein chain in your body, with more than 34,000 amino acids. This titanic protein acts like a big rubber band in our muscles. It is attached at one end to the Z-disk (shown here at the top in blue), which organizes the thin actin filaments.

Why is the full name of titin so long?

The name titin is derived from the Greek Titan (a giant deity, anything of great size). As the largest known protein, titin also has the longest IUPAC name of a protein.

Is titin muscular dystrophy genetic?

TMD is inherited in an autosomal dominant pattern, meaning that one mutated copy of the TTN gene is sufficient to cause the disease. A person with TMD has a 50% chance of passing the disease to their children. If both parents have the disease, there is a 75% chance their children will inherit the disease.

Where is titin located in the sarcomere?

Titin molecules anchor in the Z-disc and extend to the M-line region of the sarcomere. The majority of titin’s I-band region functions as a molecular spring.