BMCP1, a Novel Mitochondrial Carrier with High Expression in the Central Nervous System of Humans and Rodents, and Respiration Uncoupling Activity in Recombinant Yeast

Abstract

We report here the cloning and functional analysis of a novel homologue of the mitochondrial carriers predominantly expressed in the central nervous system and referred to as BMCP1 (brain mitochondrialcarrier protein-1). The predicted amino acid sequence of this novel mitochondrial carrier indicates a level of identity of 39, 31, or 30%, toward the mitochondrial oxoglutarate carrier, phosphate carrier, or adenine nucleotide translocator, respectively, and a level of identity of 34, 38, or 39% with the mitochondrial uncoupling proteins UCP1, UCP2, or UCP3, respectively. Northern analysis of mouse, rat, or human tissues demonstrated that mRNA of this novel gene is mainly expressed in brain, although it is 10–30-fold less expressed in other tissues.In situ hybridization analysis of brain showed it is particularly abundant in cortex, hippocampus, thalamus, amygdala, and hypothalamus. Chromosomal mapping indicates that BMCP1 is located on chromosome X of mice and at Xq24 in man. Expression of the protein in yeast strongly impaired growth rate. Analysis of respiration of total recombinant yeast or yeast spheroplasts and in particular of the relationship between respiratory rate and membrane potential of yeast spheroplasts revealed a marked uncoupling activity of respiration, suggesting that although BMCP1 sequence is more distant from the uncoupling proteins (UCPs), this protein could be a fourth member of the UCP family. We report here the cloning and functional analysis of a novel homologue of the mitochondrial carriers predominantly expressed in the central nervous system and referred to as BMCP1 (brain mitochondrialcarrier protein-1). The predicted amino acid sequence of this novel mitochondrial carrier indicates a level of identity of 39, 31, or 30%, toward the mitochondrial oxoglutarate carrier, phosphate carrier, or adenine nucleotide translocator, respectively, and a level of identity of 34, 38, or 39% with the mitochondrial uncoupling proteins UCP1, UCP2, or UCP3, respectively. Northern analysis of mouse, rat, or human tissues demonstrated that mRNA of this novel gene is mainly expressed in brain, although it is 10–30-fold less expressed in other tissues.In situ hybridization analysis of brain showed it is particularly abundant in cortex, hippocampus, thalamus, amygdala, and hypothalamus. Chromosomal mapping indicates that BMCP1 is located on chromosome X of mice and at Xq24 in man. Expression of the protein in yeast strongly impaired growth rate. Analysis of respiration of total recombinant yeast or yeast spheroplasts and in particular of the relationship between respiratory rate and membrane potential of yeast spheroplasts revealed a marked uncoupling activity of respiration, suggesting that although BMCP1 sequence is more distant from the uncoupling proteins (UCPs), this protein could be a fourth member of the UCP family. uncoupling protein carbonyl-cyanidep-trifluoromethoxyphenylhydrazone uncoupler tetraphenylphosphonium group of overlapping clones polymerase chain reaction. Thermogenic brown fat mitochondria are characterized by a mitochondrial uncoupling protein (UCP)1 (1Nicholls D.G. Locke R. Physiol. Rev. 1984; 64: 1-64Crossref PubMed Scopus (1338) Google Scholar, 2Ricquier D. Casteilla L. Bouillaud F. FASEB J. 1991; 5: 2237-2242Crossref PubMed Scopus (163) Google Scholar), recently renamed UCP1 (3Fleury C. Neverova M. Collins S. Raimbault S. Champigny O. Lévi-Meyrueis C. Bouillaud F. Seldin M.F. Surwitt R.S. Ricquier D. Warden C.H. Nat. Gen. 1997; 15: 269-272Crossref PubMed Scopus (1551) Google Scholar). UCP1 is uniquely found in brown adipose tissue and mutant mice null for the UCP1 gene are unable to maintain a normal body temperature in a cold environment (4Enerbäck S. Jacobsson A. Simpson E. Guerra C. Yamashita H. Harper M. Kozak L.P. Nature. 1997; 387: 90-94Crossref PubMed Scopus (1070) Google Scholar). Two other members of the uncoupling protein family, UCP2 and UCP3, were recently identified (3Fleury C. Neverova M. Collins S. Raimbault S. Champigny O. Lévi-Meyrueis C. Bouillaud F. Seldin M.F. Surwitt R.S. Ricquier D. Warden C.H. Nat. Gen. 1997; 15: 269-272Crossref PubMed Scopus (1551) Google Scholar,5Gimeno R. Dembski M. Weng X. Deng N. Shyjan A. Gimeno C. Iris F. Ellis S. Woolf E. Tartaglia L. Diabetes. 1997; 46: 900-906Crossref PubMed Scopus (0) Google Scholar, 6Boss O. Samec S. Paoloni G.A. Rossier C. Dulloo A. Seydoux J. Muzzin P. Giacobino J.P. FEBS Lett. 1997; 408: 39-42Crossref PubMed Scopus (996) Google Scholar, 7Vidal-Puig A. Solanes G. Grujic D. Flier J.S. Lowell B.B. Biochem. Biophys. Res. Commun. 1997; 235: 79-82Crossref PubMed Scopus (681) Google Scholar, 8Gong D.-W. He Y. Karas M. Reitman M. J. Biol. Chem. 1997; 272: 24129-24132Abstract Full Text Full Text PDF PubMed Scopus (738) Google Scholar). UCP2 mRNA is widely expressed in animal or human tissues (3Fleury C. Neverova M. Collins S. Raimbault S. Champigny O. Lévi-Meyrueis C. Bouillaud F. Seldin M.F. Surwitt R.S. Ricquier D. Warden C.H. Nat. Gen. 1997; 15: 269-272Crossref PubMed Scopus (1551) Google Scholar,5Gimeno R. Dembski M. Weng X. Deng N. Shyjan A. Gimeno C. Iris F. Ellis S. Woolf E. Tartaglia L. Diabetes. 1997; 46: 900-906Crossref PubMed Scopus (0) Google Scholar, 6Boss O. Samec S. Paoloni G.A. Rossier C. Dulloo A. Seydoux J. Muzzin P. Giacobino J.P. FEBS Lett. 1997; 408: 39-42Crossref PubMed Scopus (996) Google Scholar, 7Vidal-Puig A. Solanes G. Grujic D. Flier J.S. Lowell B.B. Biochem. Biophys. Res. Commun. 1997; 235: 79-82Crossref PubMed Scopus (681) Google Scholar, 8Gong D.-W. He Y. Karas M. Reitman M. J. Biol. Chem. 1997; 272: 24129-24132Abstract Full Text Full Text PDF PubMed Scopus (738) Google Scholar), whereas UCP3 mRNA is largely found in skeletal muscle (6Boss O. Samec S. Paoloni G.A. Rossier C. Dulloo A. Seydoux J. Muzzin P. Giacobino J.P. FEBS Lett. 1997; 408: 39-42Crossref PubMed Scopus (996) Google Scholar, 7Vidal-Puig A. Solanes G. Grujic D. Flier J.S. Lowell B.B. Biochem. Biophys. Res. Commun. 1997; 235: 79-82Crossref PubMed Scopus (681) Google Scholar, 8Gong D.-W. He Y. Karas M. Reitman M. J. Biol. Chem. 1997; 272: 24129-24132Abstract Full Text Full Text PDF PubMed Scopus (738) Google Scholar). These novel UCPs may explain proton leaks measured in mitochondria from most tissues and contribute to the partial coupling of respiration to ADP phosphorylation that exists in mitochondria from most tissues (9Rolfe D.F.S. Brown G.C. Physiol. Rev. 1997; 77: 731-758Crossref PubMed Scopus (1354) Google Scholar). Previous Northern analysis of rodent brain RNA using UCP1 cDNA or UCP2 cDNA suggested the existence of another mRNA related to the family of uncoupling proteins. 2D. Sanchis, C. Fleury, F. Bouillaud, and D. Ricquier, unpublished data. 2D. Sanchis, C. Fleury, F. Bouillaud, and D. Ricquier, unpublished data. Here, we report the cloning and functional characterization of BMCP1, a novel member of the mitochondrial carrier family that appears to be expressed in brain and, to a lesser extent, in other tissues. Although the predicted sequence of this protein is less homologous to UCP1, UCP2, or UCP3, the functional analysis of the protein when expressed in yeast indicated its potential uncoupling activity and suggested that it could be a fourth member of the UCP family. Enzymes were purchased from Appligene (Illkirsch, France) and New England Biolabs (Ozyme, Montigny-le-Bretonneux, France). [α-32P]dATP was obtained from Amersham Pharmacia Biotech (Les Ulis, France) and from NEN Life Science Products. Purified oligonucleotides were purchased from Eurogentec (Seraing, Belgium). For the cloning of mouse BMCP1, a mouse brain cDNA library (catalog number ML5004t,CLONTECH) was screened with 32P-labeled UCP1 and UCP2 cDNAs using standardized procedures. The selection of clones was confirmed using 32P-labeled insert from IMAGE clone 381344 obtained from the IMAGE Consortium and originating from human retina (GenBankTM accession number AA057007). A search in Unigene 3The World Wide Web address ishttp://www.ncbi. for uncoupling protein produced a set of expressed sequence tags that were annotated as similar to uncoupling proteins. Contig construction with the aid of further sequencing provided the information for primer design and cloning of human BMCP1. The IMAGE clone 381344 was the seed for creating a contig. A 5′ rapid amplification of cDNA ends on human brain using the Marathon cDNA Amplification kit (CLONTECH) and primers: sense 5′-TGTCACCCATCAGTATCCATC-3′ and antisense 5′-CAGTGGGGTGGTTCAAAG-3′ produced clones containing most of the human BMCP1 coding sequence. The PCR conditions used were: 94 °C 1 min and 30 cycles of 94 °C for 30 s and 68 °C for 2 min. After characterization and complete sequencing of rapid amplification of cDNA ends products, the full-length cDNA was generated using the Advantage high fidelity PCR kit, the human brain Marathon-Ready cDNA library (both fromCLONTECH), and the following PCR primer pair: sense 5′-TGGTCTCTCTCTCCCCTCAG-3′ and antisense 5′-CCACCCCACTGTTCTTCC-3′. The PCR conditions used were: 94 °C for 1 min and 30 cycles of 55 °C for 30 s and 72 °C for 3 min. Mouse (4-month-old B6D2 fed female) and rat (8-week-old lean Zucker fed male) multiple tissue blots were made from RNA prepared in the laboratory from different tissues using the guanidium thiocyanate procedure (10Chomczynski P. Sacchi N. Anal. Biochem. 1987; 162: 156-159Crossref PubMed Scopus (63082) Google Scholar). A membrane containing 2 μg of mRNA from human tissues was purchased fromCLONTECH. Hybridization and washing procedures were conducted as described previously (3Fleury C. Neverova M. Collins S. Raimbault S. Champigny O. Lévi-Meyrueis C. Bouillaud F. Seldin M.F. Surwitt R.S. Ricquier D. Warden C.H. Nat. Gen. 1997; 15: 269-272Crossref PubMed Scopus (1551) Google Scholar). Three mice were intracardially perfused with paraformaldehyde. The brains were removed and cut using a sliding microtome. 25-μm-thick sections were collected and mounted onto poly-l-lysine coated slides. The brain sections were then hybridized as described previously (11Richard D. Rivest R. Huang Q. Bouillaud F. Sanchis D. Champigny O. Ricquier D. J. Comp. Neurol. 1998; 397: 549-560Crossref PubMed Scopus (109) Google Scholar) with mouse BMCP1 sense and antisense cRNA probes. These BMCP1 cRNA probes were generated from the 979-base pair EcoRI/SacI fragment of a mouse BMCP1 cDNA subcloned into a pSELECT vector (Promega, Inc. Lyon, France), which was linearized withBamHI and EcoRI for sense and antisense probes, respectively. Yeast transfections and functional analysis using flow cytometry were carried out as described previously (3Fleury C. Neverova M. Collins S. Raimbault S. Champigny O. Lévi-Meyrueis C. Bouillaud F. Seldin M.F. Surwitt R.S. Ricquier D. Warden C.H. Nat. Gen. 1997; 15: 269-272Crossref PubMed Scopus (1551) Google Scholar, 12Bouillaud F. Arechaga I. Petit P.X. Lévi-Meyrueis C. Casteilla L. Laurent M. Rial E. Ricquier D. EMBO J. 1994; 13: 1990-1997Crossref PubMed Scopus (111) Google Scholar). Briefly, the diploid yeast (Saccharomyces cerevisiae) strain W303 was used for expression of BMCP1 or oxoglutarate carrier in the yeast expression vector pYeDP. Transformants were selected for uracil auxotrophy. Yeast strains were plated on minimal medium with glucose, supplemented with adenin and tryptophan. Liquid cultures were grown in lactate minimum medium as described (13Arechaga I. Raimbault S. Prieto S. Lévi-Meyrueis C. Zaragoza P. Miroux B. Ricquier D. Bouillaud F. Rial E. Biochem. J. 1993; 296: 693-700Crossref PubMed Scopus (82) Google Scholar). Expression of mitochondrial carriers under the control of the gal-cyc promoter was induced by galactose in absence of glucose. Measurement of the mitochondrial membrane potential of yeast was estimated by flow cytometry in the presence of the DiOC(6)3 fluorescent probe. The preparation and use of permeabilized yeast spheroplasts was made according to Averet et al. (14Averet N. Fitton V. Bunoust O. Rigoulet B. Guérin B. Mol. Cell Biochem. 1998; 184: 67-79Crossref PubMed Google Scholar). Measurement of respiration (in the presence of 6 mm NADH) was made with an oxygen electrode; measurement of mitochondrial membrane potential was determined with a tetraphenylphosphonium (TPP+) electrode as described elsewhere (15Beauseigneur F. Goubern M. Chapey M.-F. Gresti J. Vergely C. Tsoko M. Demarquoy J. Rochette L. Clouet P. Biochem. J. 1996; 320: 571-576Crossref PubMed Scopus (15) Google Scholar) under conditions where the ΔpH component was low and did not vary. To compare different spheroplast preparation, the experiments were performed using the same amount of respiratory chains as determined by the maximal respiratory rate in presence of 1 μm FCCP uncoupler. The initial state 4 of respiration was obtained in presence of oligomycin at 10 μg/ml. Then respiratory chain was titrated by the addition of potassium cyanide (concentrations ranging from 7 to 400 μm). Under these conditions, the uptake of TPP+ is proportional to the membrane potential, and independent preparations of spheroplasts or mitochondria can be accurately compared. A mouse brain cDNA library was screened using mouse UCP1 and mouse UCP2 cDNA as probes. A number of candidates clones were further screened using the human expressed sequence tag IMAGE clone 381344 (see “Experimental Procedures”). This expressed sequence tag was similar but not identical to hUCP1, hUCP2, or hUCP3. The screening led to the cloning of a mouse cDNA referred to here as BMCP1 (brain mitochondrialcarrier protein-1). The full-length cDNA of human BMCP1 was generated as described under “Experimental Procedures.” The predicted amino acid sequence of mouse and human BMCP1 is given in Fig. 1. Mouse and human BMCP1 are highly similar and share a level of identity of 97%. The predicted sequence of the mouse protein is 322 amino acids (calculated molecular mass, 36,019 daltons), and the predicted sequence for the human protein is 325 residues. The BMCP1 sequence shows the three motifs characteristic for the triplicate mitochondrial carriers (boxed in Fig. 1) and also predicts the existence of six transmembrane domains (not shown). Differences between the human and mouse sequences at amino acids 23–25 (VSG) are probably due to sequence polymorphisms, because we also identified human BMCP1 cDNA, which lacks the corresponding 9-base pair VSG motif. The levels of identity between BMCP1 and UCP1, UCP2, and UCP3 are 34, 38, and 39%, respectively. Therefore, the predicted BMCP1 sequence is less homologous to the other animal UCPs, which share 60–70% identity. BMCP1 sequence is 38% identical to the plant Solanum tuberosum UCP sequence (16Laloi M. Klein M. Riesmeier J.W. Muller-Rober B. Fleury C. Bouillaud F. Ricquier D. Nature. 1997; 389: 135-136Crossref PubMed Scopus (210) Google Scholar). A difference between BMCP1 predicted sequence and the other UCPs is in the 20 N-terminal amino acid residues in BMCP1 that are absent in UCP1, UCP2, and UCP3. This N-terminal sequence is significantly distant from known motifs implicated in the targeting of mitochondrial precursors to mitochondria. Whether this N-terminal part of BMCP1 is involved in targeting of BMCP1 into mitochondria is under investigation; preliminary data that in BMCP1 is in mitochondria. Sanchis and unpublished data. other BMCP1 is as homologous to the mitochondrial oxoglutarate carrier as it is to the other UCPs not and identity with the adenine nucleotide 1. Northern analysis of BMCP1 mRNA expression in mouse, rat, or human tissues revealed that BMCP1 is highly expressed in brain as a mRNA addition to the expression in brain, BMCP1 mRNA was also to a lesser in skeletal and adipose tissues of whereas expression was measured in of to the brain, the levels of expression of BMCP1 mRNA in other tissues of mice using a were less in less in less in in less in less in less in less in less in and less in brown adipose A expression of BMCP1 mRNA was in and of human a was obtained in brain using Northern expression was also in human and using a containing RNA from different human tissues and purchased from not shown). Fig. 3 the of BMCP1 mRNA at the level of the of the mouse hypothalamus. The expression was particularly abundant in the cortex, the hippocampus, the thalamus, the amygdala, and the hypothalamus. This from that of UCP2 mRNA (11Richard D. Rivest R. Huang Q. Bouillaud F. Sanchis D. Champigny O. Ricquier D. J. Comp. Neurol. 1998; 397: 549-560Crossref PubMed Scopus (109) Google Scholar) in that it is more The of BMCP1 mRNA to be To the activity of BMCP1 in mitochondria and for functional uncoupling BMCP1 protein was expressed in yeast as previously for UCP1 F. Arechaga I. Petit P.X. Lévi-Meyrueis C. Casteilla L. Laurent M. Rial E. Ricquier D. EMBO J. 1994; 13: 1990-1997Crossref PubMed Scopus (111) Google Scholar, I. Raimbault S. Prieto S. Lévi-Meyrueis C. Zaragoza P. Miroux B. Ricquier D. Bouillaud F. Rial E. Biochem. J. 1993; 296: 693-700Crossref PubMed Scopus (82) Google Scholar) or UCP2 (3Fleury C. Neverova M. Collins S. Raimbault S. Champigny O. Lévi-Meyrueis C. Bouillaud F. Seldin M.F. Surwitt R.S. Ricquier D. Warden C.H. Nat. Gen. 1997; 15: 269-272Crossref PubMed Scopus (1551) Google Scholar). of BMCP1 the growth rate of yeast was significantly to the vector whereas of expression of the mitochondrial oxoglutarate carrier BMCP1 expression the measured in 3 when with yeast recombinant protein 2 A similar of growth was in yeast UCP1 or UCP2 (3Fleury C. Neverova M. Collins S. Raimbault S. Champigny O. Lévi-Meyrueis C. Bouillaud F. Seldin M.F. Surwitt R.S. Ricquier D. Warden C.H. Nat. Gen. 1997; 15: 269-272Crossref PubMed Scopus (1551) Google Scholar, 12Bouillaud F. Arechaga I. Petit P.X. Lévi-Meyrueis C. Casteilla L. Laurent M. Rial E. Ricquier D. EMBO J. 1994; 13: 1990-1997Crossref PubMed Scopus (111) Google Scholar, I. Raimbault S. Prieto S. Lévi-Meyrueis C. Zaragoza P. Miroux B. Ricquier D. Bouillaud F. Rial E. Biochem. J. 1993; 296: 693-700Crossref PubMed Scopus (82) Google Scholar). To the of BMCP1 on the mitochondrial membrane potential, we used flow cytometry analysis of yeast with the fluorescent DiOC(6)3 and also permeabilized yeast spheroplasts of expression of BMCP1 for to a marked of the with the mitochondrial of yeast by flow cytometry as previously with UCP1 F. Arechaga I. Petit P.X. Lévi-Meyrueis C. Casteilla L. Laurent M. Rial E. Ricquier D. EMBO J. 1994; 13: 1990-1997Crossref PubMed Scopus (111) Google Scholar), suggesting an uncoupling activity of expression of the oxoglutarate carrier in yeast did not of the mitochondria. a of mitochondria by the fluorescent not a coupling of respiration because a of the number of mitochondria or an of other a similar of uncoupling activity of a mitochondrial protein analysis of mitochondrial The analysis of an coupling was by D.G. J. Biochem. PubMed Scopus Google Scholar) and by et al. D.F.S. Biophys. 1994; PubMed Scopus Google Scholar). We the uncoupling of BMCP1 according to this For this permeabilized yeast spheroplasts are an to mitochondria (14Averet N. Fitton V. Bunoust O. Rigoulet B. Guérin B. Mol. Cell Biochem. 1998; 184: 67-79Crossref PubMed Google activity of mouse BMCP1 expressed in analysis of respiratory rate and mitochondrial membrane potential using yeast of mitochondrial membrane potential and oxygen of control or BMCP1 yeast membrane potential was estimated from uptake of TPP+ TPP+ uptake is proportional to the mitochondrial “Experimental Procedures”). rate was measured using an oxygen electrode the respiratory to respiratory ADP oligomycin FCCP μm). The on the of the the respiratory of control or BMCP1 spheroplasts used to the in the of respiratory control corresponding to the are and for and BMCP1 respectively. relationship between respiratory rate of control or BMCP1 yeast and mitochondrial membrane potential of This was performed in the presence of oligomycin using a amount of control or BMCP1 spheroplast corresponding to the same amount of respiratory chains as determined from respiratory in presence of FCCP as in Fig. 6 A shows the of respiratory rate and mitochondrial membrane potential of control or BMCP1 of 6 mm to permeabilized spheroplasts led to a state 4 respiration to be which was in BMCP1 spheroplasts with a membrane of 2 mm ADP state 3 respiration membrane potential to the same level and revealed a coupling of respiration of BMCP1 mitochondria with control mitochondria. The on the of Fig. 6 A that addition of FCCP the respiratory activity of control whereas it the respiration of BMCP1 This was with experiments where we used different preparations of spheroplasts corresponding to independent cultures of as as independent of yeast to out the of a due to the The respiratory control as the between respiratory rate in presence of and respiratory rate in state 4 of of spheroplasts from yeast BMCP1 or not BMCP1 were and These data confirmed a coupling of respiration in yeast BMCP1 with control D.G. J. Biochem. PubMed Scopus Google Scholar) and et al. D.F.S. Biophys. 1994; PubMed Scopus Google Scholar) that the measurement of the relationship between mitochondrial membrane potential and state 4 respiratory rate (in presence of in and proton leaks mitochondrial This was to yeast To in Fig. 6 of control and BMCP1 permeabilized spheroplasts were to the same FCCP maximal respiratory rate. it is that the same of mitochondria by the same maximal activity of the respiratory chain was in Fig. 6 obtained in presence of and was by potassium cyanide according to D.G. J. Biochem. PubMed Scopus Google and D.F.S. Biophys. 1994; PubMed Scopus Google and “Experimental Procedures”). the rate of the membrane potential with a TPP+ electrode in conditions where TPP+ uptake is proportional to membrane potential, the component of the and the proton The of the of BMCP1 spheroplasts with control spheroplasts shows an respiratory rate of the of membrane The membrane potential with respiratory rate in BMCP1 spheroplasts suggested out the that be due to an of a mitochondrial to D.G. J. Biochem. PubMed Scopus Google Scholar) and et al. D.F.S. Biophys. 1994; PubMed Scopus Google Scholar), these data that BMCP1 expression induced an uncoupling of mitochondrial respiration in recombinant yeast and that addition of BMCP1 to mitochondria a proton the of it may be that BMCP1 to the mitochondrial proton measured in brain mitochondria M. Biophys. 1994; Scopus Google Scholar). Whether BMCP1 the of respiration in brain in to be preliminary experiments we the of a of BMCP1 activity in yeast by acids or that are known or of UCP1 (1Nicholls D.G. Locke R. Physiol. Rev. 1984; 64: 1-64Crossref PubMed Scopus (1338) Google Scholar) and The of BMCP1 activity by particular be an uncoupling activity of a mitochondrial carrier homologous to the UCPs is not because it was that the adenine of which identity with UCP1, UCP2, UCP3, or BMCP1, can the uncoupling of acids Biophys. 1998; PubMed Scopus Google Scholar). the data here not out another activity of BMCP1. We determined the of BMCP1 in mice and are with the presence of a BMCP1 on the X a sequence was from IMAGE clone accession number which is part of the human BMCP1 The was to human chromosome X between and BMCP1 between and on the human gene on the The of mouse BMCP1 was determined in a characterized as described previously (3Fleury C. Neverova M. Collins S. Raimbault S. Champigny O. Lévi-Meyrueis C. Bouillaud F. Seldin M.F. Surwitt R.S. Ricquier D. Warden C.H. Nat. Gen. 1997; 15: 269-272Crossref PubMed Scopus (1551) Google Scholar). A fragment was used to to the X chromosome at with This predicts that the human homologue be on the X chromosome at which is the same identified by sequence The mouse BMCP1 is in the for mouse for body These were body 1 and BMCP1 may be a for these body although are most of the X the which is also part of the same mitochondrial carrier family as BMCP1, to This the that BMCP1 and may be with we report here the cloning of cDNAs a mouse or human mitochondrial carrier protein that we to to as BMCP1. BMCP1 gene is located on chromosome X. the of the predicted amino acid this protein to the family of mitochondrial carriers and is homologous to mitochondrial oxoglutarate carrier and when it is expressed in the analysis of the relationship between the respiratory rate and the mitochondrial membrane potential indicates that BMCP1 as a uncoupler of The expression of BMCP1 in brain the as to the and for BMCP1 in for the to or level of oxygen We the of M. F. Chapey and G. for these