title: A mammalian mitochondrial drug receptor functions as a bacterial "oxygen" sensor.
abstract: The rat mitochondrial outer membrane-localized benzodiazepine receptor (MBR) was expressed in wild-type and TspO- (tryptophan-rich sensory protein) strains of the facultative photoheterotroph, Rhodobacter sphaeroides 2.4.1, and was shown to retain its structure within the bacterial outer membrane as assayed by its binding properties with a variety of MBR ligands. Functionally, it was able to substitute for TspO by negatively regulating the expression of photosynthesis genes in response to oxygen. This effect was reversed pharmacologically with the MBR ligand PK11195. These results suggest a close evolutionary and functional relationship between the bacterial TspO and the MBR. This relationship provides further support for the origin of the mammalian mitochondrion from a "photosynthetic" precursor. Finally, these findings provide novel insights into the physiological role that has been obscure for the MBR in situ.
authors.affiliation: Department of Microbiology and Molecular Genetics, University of Texas Health Science Center at Houston Medical School, P.O. Box 20708, Houston, TX 77225, USA.
authors.forename: A A
authors.initials: AA
authors.lastname: Yeliseev
authors.forename: K E
authors.initials: KE
authors.lastname: Krueger
authors.forename: S
authors.initials: S
authors.lastname: Kaplan
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D001426:Bacterial Proteins / Q000737:chemistry* / Q000502:physiology*; D005075:Biological Evolution; D002462:Cell Membrane / Q000502:physiology; D017124:Conserved Sequence; D007425:Intracellular Membranes / Q000378:metabolism*; D007546:Isoquinolines / Q000378:metabolism / Q000494:pharmacology; D007700:Kinetics; D008024:Ligands; D008322:Mammals; D008565:Membrane Proteins / Q000737:chemistry* / Q000502:physiology*; D008928:Mitochondria / Q000378:metabolism*; D008969:Molecular Sequence Data; D010100:Oxygen / Q000378:metabolism*; D051381:Rats; D011963:Receptors, GABA-A / Q000096:biosynthesis / Q000737:chemistry* / Q000502:physiology*; D011994:Recombinant Proteins / Q000096:biosynthesis / Q000378:metabolism; D012242:Rhodobacter sphaeroides / Q000502:physiology*; D017386:Sequence Homology, Amino Acid; D014158:Transcription, Genetic / Q000187:drug effects; D001616:beta-Galactosidase / Q000096:biosynthesis
chemical_list: D001426:Bacterial Proteins; D007546:Isoquinolines; D008024:Ligands; D008565:Membrane Proteins; D011963:Receptors, GABA-A; D011994:Recombinant Proteins; C069075:CrtK protein, Rhodobacter capsulatus; D001616:beta-Galactosidase; D010100:Oxygen; C051238:PK 14105; C037850:PK 11195