Cyclophilin B (PPIB) Recombinant Protein

The protein encoded by this gene is a cyclosporine-binding protein and is mainly located within the endoplasmic reticulum. It is associated with the secretory pathway and released in biological fluids. This protein can bind to cells derived from T- and B-lymphocytes, and may regulate cyclosporine A-mediated immunosuppression. Variants have been identified in this protein that give rise to recessive forms of osteogenesis imperfecta. [provided by RefSeq, Oct 2009]

PPIB: PPIases accelerate the folding of proteins. It catalyzes the cis-trans isomerization of proline imidic peptide bonds in oligopeptides. Defects in PPIB are the cause of osteogenesis imperfecta type 9 (OI9). OI9 is a connective tissue disorder characterized by bone fragility, low bone mass and bowing of limbs due to multiple fractures. Short limb dwarfism and blue sclerae are observed in some but not all patients. Belongs to the cyclophilin-type PPIase family. PPIase B subfamily.

Protein type: Cyclophilin; Secreted, signal peptide; EC 5.2.1.8; Isomerase; Secreted; RNA-binding; Chaperone

Chromosomal Location of Human Ortholog: 15q21-q22

Cellular Component: smooth endoplasmic reticulum; focal adhesion; membrane; endoplasmic reticulum; perinuclear region of cytoplasm; endoplasmic reticulum lumen; melanosome; nucleus

Molecular Function: collagen binding; protein binding; peptidyl-prolyl cis-trans isomerase activity; unfolded protein binding; protein complex binding; peptide binding

Biological Process: extracellular matrix organization and biogenesis; protein peptidyl-prolyl isomerization; protein stabilization; positive regulation of multicellular organism growth

Disease: Osteogenesis Imperfecta, Type Ix