GDF-8 propeptide binds to GDF-8 and antagonizes biological activity by inhibiting GDF-8 receptor binding.
GDF-8 is a new member of the TGF-beta superfamily which appears to be a negative regulator of skeletal muscle mass. Factors which regulate the biological activity of GDF-8 have not yet been identified. However, the biological activities of TGF-beta superfamily members, TGF-beta1, -beta2 and -beta3, can be inhibited by noncovalent association with TGF-beta1, -beta2 and beta3 propeptides cleaved from the amino-termini of the TGF-beta precursor proteins. In contrast, the propeptides of other TGF-beta superfamily members do not appear to be inhibitory. In this investigation, we demonstrate that purified recombinant GDF-8 propeptide associates with purified recombinant GDF-8 to form a noncovalent complex, as evidenced by size exclusion chromatography and chemical crosslinking analysis. Furthermore, we show that GDF-8 propeptide inhibits the biological activity of GDF-8 assayed on A204 rhabdomyosarcoma cells transfected with a (CAGA)12 reporter construct. Finally, we demonstrate that GDF-8 propeptide inhibits specific GDF-8 binding to L6 myoblast cells. Collectively, these data identify the GDF-8 propeptide as an inhibitor of GDF-8 biological activity.
Thies
R S
RS
Genetics Institute, Inc., Cambridge, MA 02140, USA. sthies@genetics.com
Chen
T
T
Davies
M V
MV
Tomkinson
K N
KN
Pearson
A A
AA
Shakey
Q A
QA
Wolfman
N M
NM
D000818:Animals; D019485:Bone Morphogenetic Proteins / Q000037:antagonists & inhibitors; D016466:CHO Cells; D002460:Cell Line; D006224:Cricetinae; D006133:Growth Substances / Q000235:genetics / Q000302:isolation & purification / Q000378:metabolism*; D006801:Humans; D066298:In Vitro Techniques; D007700:Kinetics; D055435:Myostatin; D011498:Protein Precursors / Q000235:genetics / Q000302:isolation & purification / Q000378:metabolism*; D017978:Receptors, Growth Factor / Q000378:metabolism; D011994:Recombinant Proteins / Q000235:genetics / Q000302:isolation & purification / Q000378:metabolism; D016212:Transforming Growth Factor beta / Q000037:antagonists & inhibitors* / Q000235:genetics / Q000302:isolation & purification / Q000378:metabolism*; D029867:Xenopus Proteins
D019485:Bone Morphogenetic Proteins; C118643:GDF11.1 protein, Xenopus; D006133:Growth Substances; C525911:MSTN protein, human; D055435:Myostatin; D011498:Protein Precursors; D017978:Receptors, Growth Factor; D011994:Recombinant Proteins; D016212:Transforming Growth Factor beta; D029867:Xenopus Proteins