What is Follistatin 315 ?

Follistatin is a single-chain gonadal protein that specifically inhibits follicle-stimulating hormone release. 

The single FST gene encodes two isoforms, FST317 and FST344 containing 317 and 344 amino acids respectively, resulting from alternative splicing of the precursor mRNA. 

In a study in which 37 candidate genes were tested for linkage and association with polycystic ovary syndrome (PCOS) or hyperandrogenemia in 150 families, evidence was found for linkage between PCOS and follistatin.

Follistatin (FST) is a secreted glycoprotein that was first identified as a follicle­stimulating hormone inhibiting substance in ovarian follicular fluid (1, 2). Human Follistatin cDNA encodes a 344 amino acid (aa) protein with a 29 aa signal sequence, an N­terminal atypical TGF binding domain, three Follistatin domains that contain EGF­like and kazal­like motifs, and a highly acidic C­terminal tail. Follistatin is a secreted protein that binds to ligands of the TGF-Beta family and regulates their activity by inhibiting their access to signaling receptors. It was originally discovered as activin antagonists whose activity suppresses expression and secretion of the pituitary hormone FSH (follicle stimulating hormone). In addition to being a natural antagonist, follistatin can inhibit the activity of other TGF-Beta ligands including BMP-2,-4,-6,-7, Myostatin, GDF-11, and TGF-Beta1. Follistatin is expressed in the pituitary, ovaries, decidual cells of the endometrium, and in some other tissues. Recombinant human Follistatin 315 is a 34.7 kDa protein containing amino acids 30-344 of the FST-344 protein.

Follistatin Use in Muscle Growth:

Follistatin works by binding to and inhibiting transforming growth factor- (TGF-) peptides such as myostatin which is responsible for regulating and limiting muscle growth.  It's also worth pointing out that myostatin may have a regulatory role in skeletal muscle fibrosis; too much myostatin can impair tissue function and cause chronic disease in vital organs, tissues, and bone marrow. 

In additional to suppressing the degenerative properties of myostatin, follistatin also suppresses the pituitary gland synthesis and secretion of follicle-stimulating hormone (FSH). [1] High FSH levels in men may indicate that testicles are not functioning correctly; this condition limits muscle growth, recovery, and normal hormonal function.However, FSH levels that are too low can also negatively impact health and reproductive capabilities.

Application :

Follistatin 315 primary function is the binding and bioneutralization of members of the TGF-β superfamily, with a 

particular focus on activin, a paracrine hormone.

Storage Instruction

Store at +4°C or at -20°C if preferred. Storage in frost-free freezers is not recommended. This product should be 

stored undiluted. Avoid repeated freezing and thawing as this may denature the antibody. Should this product 

contain a precipitate we recommend microcentrifugation before use.