PeptideHormone

MyostatinGDF-8

The TGF-β-family brake that limits skeletal muscle mass.

EndogenousEstablished

Identity

Class
TGF-β superfamily growth/differentiation factor (secreted dimer)
Source
Skeletal muscle
Receptor
Activin type II receptors (ActRIIB) → Smad2/3

Mechanism

Myostatin signals through activin type II receptors and the Smad2/3 pathway to restrain muscle growth — a negative regulator. Animals and rare humans lacking functional myostatin develop pronounced muscle hypertrophy, which is why blocking it is pursued therapeutically.

Reference notes

  • Loss of myostatin causes dramatic muscle overgrowth across species — the clearest evidence of its braking role.
  • It signals through activin type II receptors and Smad2/3, not a GPCR.
  • Blocking myostatin is a leading strategy for muscle preservation, including during incretin-driven weight loss.

Selected literature

Curated peer-reviewed reviews, sourced from PubMed. Selected for relevance, not exhaustive — open any entry on PubMed for the full record and its primary citations.

  1. 1.Mechanisms regulating skeletal muscle growth and atrophy · The FEBS journal, 2013 · PMID 23517348
  2. 2.Myostatin/Activin Receptor Ligands in Muscle and the Development Status of Attenuating Drugs · Endocrine reviews, 2022 · PMID 34520530