Definition
Myostatin is a kind of TGF-β family discovered as a factor involved in the modulation of the number of muscles. It inhibits the growth of skeletal muscles, and in knockout mice, an increase in skeletal muscles and a decrease in body fat mass have been reported. Myostatin activity is inhibited by follistatin, an activin-binding protein and myostatin propeptide. Growth Differentiation Factor 8 (GDF-8), also known as myostatin, is a member of the TGF-beta superfamily expressed specifically in developing and adult skeletal muscle. GDF-8 cDNA encodes a 376 amino acid (aa) prepropeptide with a 24 aa residue signal peptide, a 223 aa residue amino-terminal propeptide, and a 109 aa residue carboxy-terminal mature protein. Mature GDF-8 contains the canonical 7-cysteine motif common to other TGF-beta superfamily members.
Biological Activity
Myostatin (GDF-8), a member of the TGF-beta superfamily of growth and differentiation factors, is most well-known as a potent suppressor of muscle growth, development, and regeneration. Mice lacking myostatin show a significant increase in muscle mass, and congenital absence of myostatin is associated with increased muscle mass in both humans and dogs. It has also been shown that factors which inhibit myostatin, such as follistatin, can improve muscle regeneration and decrease fibrosis in injured muscles[1].
References
[1] Mark W Hamrick. “Recombinant myostatin (GDF-8) propeptide enhances the repair and regeneration of both muscle and bone in a model of deep penetrant musculoskeletal injury.” Journal of Trauma-Injury Infection and Critical Care 69 3 (2010): 579–83.
