Gene Summary: The protein encoded by PPIB 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]General information above from NCBI
Catalytic activity: Peptidylproline (omega=180) = peptidylproline (omega=0).
Enzyme regulation: Cyclosporin A (CsA) inhibits CYPB.
Subunit structure: Interacts with DYM.
Subcellular location: Endoplasmic reticulum lumen. Melanosome. Note=Identified by mass spectrometry in melanosome fractions from stage I to stage IV.
Involvement in disease: Osteogenesis imperfecta 9 (OI9) [MIM:259440]: A form of osteogenesis imperfecta, a connective tissue disorder characterized by low bone mass, bone fragility and susceptibility to fractures after minimal trauma. Disease severity ranges from very mild forms without fractures to intrauterine fractures and perinatal lethality. Extraskeletal manifestations, which affect a variable number of patients, are dentinogenesis imperfecta, hearing loss, and blue sclerae. OI9 is a severe autosomal recessive form of the disorder. Note=The disease is caused by mutations affecting the gene represented in this entry.
Sequence similarity: Belongs to the cyclophilin-type PPIase family. PPIase B subfamily.
Contains 1 PPIase cyclophilin-type domain.
General information above from UniProt