Translocator protein 2 (TSPO2)

Translocator protein 2 (TSPO2) is a cholesterol-binding transmembrane protein selectively expressed in late erythroblasts, where it plays a critical role in the redistribution of intracellular cholesterol from lipid droplets to the endoplasmic reticulum[1][4]. This function is vital for efficient cell-cycle progression, cytokinesis, and terminal maturation of erythroid progenitor cells. TSPO2's unique erythroid-specific expression distinguishes it from its paralog TSPO (18 kDa), which is found ubiquitously and is best known for its role in steroidogenesis and mitochondrial function. Mutations in the TSPO2 gene disrupt intracellular cholesterol handling, resulting in defective erythrocyte maturation, increased apoptosis, and compensated anemia, as seen in both naturally occurring (e.g., HK trait in dogs) and experimental knockout models[1]. While TSPO2 forms complexes with other membrane proteins and may participate in membrane transport of heme analogs or ATP, direct drug targeting and therapeutic exploitation have not yet been realized. The importance of TSPO2 in erythroid biology makes it a key molecule in human and veterinary hematology research[1][4].

Other names

Peripheral-type benzodiazepine receptor-like protein 1BZRPL1dJ34B21.2similar to RIKEN cDNA 2510027D20benzodiazepine receptor (peripheral)-like 1

Not established for drugs, but mechanistically, TSPO2 alters intracellular cholesterol redistribution and regulates erythroid cell proliferation and maturation