Follistatin is a secreted protein that binds to ligands of the TGF (transforming growth factor)-β family and regulates their activity by inhibiting their access to signaling receptors. Follistatin is expressed in the pituitary, ovaries, decidual cells of the endometrium, and in some other tissues. The gene is mapped to human chromosome 5q11.2. Recombinant human Follistatin is a 31.5kDa protein containing 288 amino acids. Its primary structure contains three cysteine-rich domains (called FS domains), each followed by a protease-inhibitory kazal domain.
Follistatin human has been used to suppress myostatin signaling. It has also been used as an inhibitor of activin A.
Follistatin is a multifunctional protein. 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 (transforming growth factor)-β ligands including BMP (bone morphogenetic protein)-2,-4,-6,-7, Myostatin, GDF-11 (growth differentiation factor 11), and TGF-b1. In gonads, it is responsible for oocyte competence and embryo development. In the pituitary gland, it causes cyclic changes in FSH production in the estrous cycle. Follistatin also participates in bone metabolism. It controls inflammation, fibrosis and tissue repair. Levels of plasma follistatin increases in polycystic ovary syndrome and type 2 diabetes. Follistatin might also be involved in tumor progression, including apoptosis, angiogenesis, and metastasis.
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Lyophilized from 10 mM sodium phosphate, 50 mM sodium chloride, pH 7.5.
Centrifuge the vial prior to opening. Reconstitute in water to a concentration of 0.1-1.0 mg/ml. Do not vortex. This solution can be stored at 2-8°C for up to 1 week. For extended storage, it is recommended to further dilute in a buffer containing a carrier protein (example 0.1% BSA) and store in working aliquots at -20°C to -80°C.