Follistatin
Follistatin, encoded by the FSTL3 gene and also known as follistatin-like 3, FLRG or FSRP, is a secreted glycoprotein of the follistatin-module-protein family. It binds and antagonises TGF-beta family members, including activin, BMP2 and myostatin. Browse Assay Genie's current range of Follistatin research reagents below, or read on for the biology behind the target.
The secreted form of follistatin (isoform 1) is a binding and antagonising protein for members of the TGF-beta family, such as activin, BMP2 and myostatin (MSTN). By binding these ligands it inhibits activin A-, activin B-, BMP2- and myostatin-induced cellular signalling, and it is more effective against activin A than against activin B. This makes it a useful point of study for researchers examining how TGF-beta family signalling is restrained outside the cell.
Beyond ligand neutralisation, the secreted protein has been linked to bone formation, where it inhibits osteoclast differentiation. It is also involved in haematopoiesis: it contributes to the differentiation of haematopoietic progenitor cells, increases haematopoietic cell adhesion to fibronectin and appears to support the adhesion of haematopoietic precursor cells to the bone marrow stroma.
The FSTL3 gene also gives rise to a nuclear form (isoform 2), which is probably involved in transcriptional regulation through interaction with MLLT10. The protein is a member of the follistatin-module-protein family, and the gene is conserved with mouse and rat orthologs, both named Fstl3. The official gene name was previously written as follistatin-like 3 (secreted glycoprotein), and the protein is also called follistatin-related protein 3. NCBI Gene notes that it may have a role in leukaemogenesis.
Follistatin antagonises activin, BMP2 and myostatin, so it is studied to understand how extracellular inhibitors shape TGF-beta family signalling.
The secreted protein is involved in bone formation and inhibits osteoclast differentiation, making it relevant to studies of bone remodelling.
It influences haematopoietic progenitor differentiation and adhesion to fibronectin and bone marrow stroma, informing work on the haematopoietic niche.
The nuclear isoform probably regulates transcription via MLLT10, and the gene may have a role in leukaemogenesis.
The secreted form binds and antagonises TGF-beta family members including activin, BMP2 and myostatin, inhibiting their signalling. It is more effective on activin A than activin B. It also inhibits osteoclast differentiation and takes part in haematopoietic cell differentiation and adhesion.
Follistatin here is the FSTL3 gene product, also called follistatin-like 3, follistatin-related protein 3, FLRG and FSRP. Isoform 1 is the secreted form, while isoform 2 is a nuclear form probably involved in transcriptional regulation through MLLT10.
Mouse and rat both have an ortholog named Fstl3. NCBI Gene reports that the protein may have a role in leukaemogenesis. Check the datasheet of any product for its validated reactivity before choosing a species.
TGF-beta family ligands, their binding partners and haematopoietic and bone biology targets that sit alongside follistatin.
Gene and protein annotations from HGNC, NCBI Gene and UniProt O95633; product specifications from Assay Genie datasheets.