Cyclophilin B Blocking Peptide

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

Chromosomal Location of Human Ortholog: 15q21-q22

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

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

Biological Process: positive regulation of multicellular organism growth; protein peptidyl-prolyl isomerization; protein stabilization

Disease: Osteogenesis Imperfecta, Type Ix