PK11195, benzodiazepine receptor antagonist

Supplementary information

This supplementary information is collated from multiple sources and compiled automatically.

PBR also known as the Peripheral Benzodiazepine Receptor is a protein predominantly found in the outer mitochondrial membrane. It has alternate names like Translocator Protein (TSPO) and the mass of this protein is approximately 18 kDa. PBR is expressed in various tissues but shows high levels in steroidogenic tissues like adrenal glands as well as in the brain heart liver and kidneys. The abundant presence in these tissues highlights its importance in a variety of physiological functions.

Biological function summary

PBR interacts with cholesterol for the synthesis of steroid hormones making it important for steroidogenesis. PBR is a part of the Mitochondrial Permeability Transition Pore complex (MPTP) involved in regulating the transport of molecules across the mitochondrial membrane. Through its association with the MPTP PBR plays a significant role in mitochondrial functions such as apoptosis and energy metabolism. The interaction with other molecules also includes the binding with benzodiazepines impacting processes like immune response and cell proliferation.

Pathways

PBR plays a role in the steroid biosynthesis and apoptosis pathways. It interfaces with the StAR (Steroidogenic Acute Regulatory) protein to facilitate cholesterol transport into mitochondria the initial step in steroid hormone production. PBR is also involved in pathways that regulate apoptosis and mitochondrial function linking it to different cellular processes through interactions with proteins like VDAC (Voltage-Dependent Anion Channel).

PBR has relevance to conditions such as neurodegenerative diseases and cancer. PBR expression changes in disorders like Alzheimer's disease where it might reflect mitochondrial dysfunctions. It has also been associated with certain cancers where aberrant PBR activity might contribute to altered cell proliferation and apoptosis. Proteins like caspases are involved in the apoptotic pathways connected with PBR highlighting its involvement in disease processes.