Myostatin (latent complex form) (MSTN (or GDF-8, Growth differentiation factor 8))

Latent myostatin refers to the precursor complex of myostatin, a negative regulator of skeletal muscle mass and member of the transforming growth factor-β (TGF-β) superfamily[1][5]. Synthesized as pre-pro-myostatin, sequential proteolytic cleavages yield a non-covalent complex between the mature (“growth factor”) dimer and its N-terminal propeptide, termed latent myostatin[4][5][6]. In this form, myostatin remains inactive, as the propeptide blocks the receptor-binding domain essential for signaling. Activation occurs upon further cleavage (by BMP1/tolloid proteases), liberating mature myostatin, which binds to the activin type II receptor and initiates a SMAD-mediated signaling cascade that inhibits muscle growth and regulates muscle fiber number and size[1][2][3][4]. Latent myostatin is the major extracellular storage and regulatory form in muscle tissue[5][7]. Dysregulation of this pathway is implicated in muscle wasting diseases, making both latent and mature forms of myostatin attractive therapeutic targets for conditions such as muscular dystrophy, cachexia, and sarcopenia. Several pharmaceutical strategies address latent myostatin by preventing its activation or blocking its receptor interaction. Modulation of this axis must be balanced carefully due to safety concerns, particularly regarding muscle-bone homeostasis, cardiac function, and possible effects on other tissues[3][4][5][7].

Other names

Growth differentiation factor 8 (GDF-8)Pro-myostatinLatent myostatin complexLatent GDF-8

Drugs act by: - Blocking mature myostatin or preventing its activation from the latent complex - Inhibiting the myostatin-activin type II receptor interaction - Mimicking endogenous antagonists (such as follistatin) to prevent receptor activation - Inhibiting furin/BMP-1/tolloid cleavage that activates the latent complex