Follistatin 344: Complete Research Compound Profile
Follistatin 344 (FST-344) is a naturally occurring glycoprotein and a potent antagonist of activin and myostatin — members of the TGF-β superfamily. As a key regulator of muscle growth, reproductive biology, and inflammation, Follistatin 344 has become one of the most studied proteins in regenerative medicine research. This guide covers its molecular biology, mechanism, and research applications.
Molecular Profile
| Parameter | Specification |
|---|---|
| Full Name | Follistatin Isoform FST-344 |
| Type | Single-chain glycoprotein |
| Amino Acids | 344 (precursor) → 315 (mature) |
| Molecular Weight | ~38 kDa (glycosylated) |
| Disulfide Bonds | Multiple (essential for structure) |
| Isoforms | FST-288 (tissue-bound), FST-315 (circulating) |
| Storage | -20°C to -80°C lyophilized |
Mechanism of Action
Myostatin Neutralization
The primary research interest in Follistatin centers on its ability to bind and neutralize myostatin (GDF-8). Myostatin is a negative regulator of skeletal muscle growth — it limits muscle mass by inhibiting myoblast proliferation and differentiation. Follistatin binds myostatin with high affinity, preventing it from signaling through ActRIIB receptors, effectively removing the “brake” on muscle growth.
Activin Antagonism
Follistatin also binds and neutralizes activin A and activin B. Activin signaling is involved in FSH regulation and reproductive function, inflammatory responses, fibrotic processes, and cell proliferation and differentiation.
TGF-β Superfamily Regulation
Beyond myostatin and activin, follistatin interacts with several other TGF-β superfamily members including BMP-2, BMP-4, BMP-6, BMP-7, and BMP-15, making it a broad-spectrum regulator of this critical signaling family.
Key Research Areas
Muscle Biology
Follistatin gene therapy and recombinant protein studies have demonstrated dramatic increases in muscle mass in animal models. Myostatin knockout mice (and natural myostatin mutations in Belgian Blue cattle) show doubled muscle mass, and follistatin overexpression produces similar effects through myostatin neutralization.
Muscular Dystrophy Research
Follistatin has been investigated as a potential therapeutic approach for Duchenne muscular dystrophy (DMD) and other myopathies. AAV-mediated follistatin gene delivery has shown improved muscle function and histology in mdx mice and non-human primate models.
Reproductive Biology
Follistatin plays critical roles in reproductive biology through activin regulation, including FSH secretion modulation, ovarian follicle development, placental biology, and gonadal function.
Fibrosis Research
The anti-activin properties of follistatin are being explored in fibrosis research, including hepatic fibrosis, pulmonary fibrosis, and cardiac fibrosis models.
FST-344 vs FST-315 vs FST-288
- FST-344: Precursor form that is processed to FST-315. Most commonly available as recombinant research protein.
- FST-315: Circulating isoform with a C-terminal acidic tail that prevents heparin binding, allowing it to act systemically.
- FST-288: Tissue-bound isoform that binds cell-surface heparan sulfate proteoglycans, acting locally in specific tissues.
Research-Grade Follistatin from Aarise Healthcare
Aarise Healthcare supplies research-grade Follistatin 344 with documented purity and bioactivity for qualified research institutions. View our Follistatin 344 product or contact us for research supply inquiries.
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