Peptidyl-prolyl cis-trans isomerase FKBP1A (FKBP1A)

Keeps in an inactive conformation TGFBR1, the TGF-beta kind I serine/threonine kinase receptor, preventing TGF-beta receptor activation in absence of ligand. Recruits SMAD7 into ACVR1B which prevents the institution of SMAD2 and SMAD3 using the activin receptor complex, thereby blocking the activin signal.

May regulate the RYR1 calcium channel activity. PPIases accelerate the folding of proteins.