Translocator protein (TSPO) is an 18 kDa protein mainly found on the outer mitochondrial membrane.[5] It was first described as peripheral benzodiazepine receptor (PBR), a secondary binding site for diazepam, but subsequent research has found the receptor to be expressed throughout the body and brain.[6] In humans, the translocator protein is encoded by the TSPOgene.[7][8] It belongs to a family of tryptophan-rich sensory proteins. Regarding intramitochondrial cholesterol transport, TSPO has been proposed to interact with StAR (steroidogenic acute regulatory protein) to transport cholesterol into mitochondria, though evidence is mixed.[9]
^Papadopoulos V, Baraldi M, Guilarte TR, Knudsen TB, Lacapère JJ, Lindemann P, et al. (August 2006). "Translocator protein (18kDa): new nomenclature for the peripheral-type benzodiazepine receptor based on its structure and molecular function". Trends in Pharmacological Sciences. 27 (8): 402–409. doi:10.1016/j.tips.2006.06.005. PMID16822554.
^Chang YJ, McCabe RT, Rennert H, Budarf ML, Sayegh R, Emanuel BS, et al. (1992). "The human "peripheral-type" benzodiazepine receptor: regional mapping of the gene and characterization of the receptor expressed from cDNA". DNA and Cell Biology. 11 (6): 471–480. doi:10.1089/dna.1992.11.471. PMID1326278.
^Bogan RL, Davis TL, Niswender GD (April 2007). "Peripheral-type benzodiazepine receptor (PBR) aggregation and absence of steroidogenic acute regulatory protein (StAR)/PBR association in the mitochondrial membrane as determined by bioluminescence resonance energy transfer (BRET)". The Journal of Steroid Biochemistry and Molecular Biology. 104 (1–2): 61–67. doi:10.1016/j.jsbmb.2006.10.007. PMID17197174. S2CID24634653.