Gut P, Zweckstetter M, Banati RB. Lost in translocation: the functions of the 18-kD translocator protein.
Trends Endocrinol Metab 2015;
26:349-56. [PMID:
26026242 PMCID:
PMC5654500 DOI:
10.1016/j.tem.2015.04.001]
[Citation(s) in RCA: 52] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/06/2015] [Revised: 03/31/2015] [Accepted: 04/21/2015] [Indexed: 01/29/2023]
Abstract
Research spanning nearly four decades has assigned to the translocator protein (18 kDa) (TSPO) a critical role, among others, in the mitochondrial import of cholesterol, the subsequent steps of (neuro)steroid production, and systemic endocrine regulation, with implications for the pathophysiology of immune, inflammatory, neurodegenerative, and psychiatric as well as neoplastic diseases. Recent knockout studies in mice unexpectedly report normal or latent phenotypes, raising doubts about the protein's role in steroidogenesis and other previously postulated functions and challenging the validity of earlier data on the selectivity of TSPO-binding drugs. Here we provide a synthesis of the current debate from a structural and molecular biology perspective, discuss the limits of inference in loss-of-function (gene knockout) studies, and suggest new functions of TSPO.
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