Myostatin precursor (GDF-8 (for mature myostatin); no established abbreviation specific to "promyostatin" or "latent myostatin")

The myostatin precursor (pro-myostatin) is the full-length, inactive form of the muscle growth regulator myostatin, a member of the TGF-β superfamily. Synthesized in muscle cells, pro-myostatin contains an N-terminal pro-domain and a C-terminal mature growth factor (GF) domain, forming a V-shaped, disulfide-linked homodimer[1][4][5]. Following secretion, this precursor remains biologically inactive as either "pro-myostatin" (uncleaved) or "latent myostatin" (after initial furin cleavage but prior to final activation)[1][2][7]. Latency is mediated by non-covalent binding of the pro-domain to the mature GF, preventing receptor binding and signaling. Upon stepwise extracellular proteolytic cleavage events—primarily by furin, then tolloid proteases—the pro-domain is released, allowing mature myostatin to bind activin type II receptors and initiate a SMAD-dependent signaling cascade, suppressing muscle growth and differentiation[3][4]. Therapeutically, targeting pro- or latent myostatin has been a focus for muscle wasting disorders. However, drug development faces challenges from structural homology within the TGF-β superfamily and the requirement for precise modulation of myostatin activity to avoid adverse effects[6][7][8].

Other names

Growth differentiation factor 8 precursorPro-myostatinLatent myostatinMSTN precursor

Antibody or peptide inhibition of pro-domain cleavage, thereby blocking maturation/activation of myostatin; Stabilization of the latent complex to prevent functional release of the mature myostatin growth factor