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Franco LVR, Su CH, Simas Teixeira L, Almeida Clarck Chagas J, Barros MH, Tzagoloff A. Allotopic expression of COX6 elucidates Atco-driven co-assembly of cytochrome oxidase and ATP synthase. Life Sci Alliance 2023; 6:e202301965. [PMID: 37604582 PMCID: PMC10442929 DOI: 10.26508/lsa.202301965] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2023] [Revised: 08/03/2023] [Accepted: 08/07/2023] [Indexed: 08/23/2023] Open
Abstract
The Cox6 subunit of Saccharomyces cerevisiae cytochrome oxidase (COX) and the Atp9 subunit of the ATP synthase are encoded in nuclear and mitochondrial DNA, respectively. The two proteins interact to form Atco complexes that serve as the source of Atp9 for ATP synthase assembly. To determine if Atco is also a precursor of COX, we pulse-labeled Cox6 in isolated mitochondria of a cox6 nuclear mutant with COX6 in mitochondrial DNA. Only a small fraction of the newly translated Cox6 was found to be present in Atco, which can explain the low concentration of COX and poor complementation of the cox6 mutation by the allotopic gene. This and other pieces of evidence presented in this study indicate that Atco is an obligatory source of Cox6 for COX biogenesis. Together with our finding that atp9 mutants fail to assemble COX, we propose a regulatory model in which Atco unidirectionally couples the biogenesis of COX to that of the ATP synthase to maintain a proper ratio of these two complexes of oxidative phosphorylation.
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Affiliation(s)
- Leticia Veloso R Franco
- https://ror.org/00hj8s172 Department of Biological Sciences, Columbia University, New York, NY, USA
- https://ror.org/036rp1748 Instituto de Ciências Biomédicas, Universidade de São Paulo, São Paulo, Brasil
| | - Chen-Hsien Su
- https://ror.org/00hj8s172 Department of Biological Sciences, Columbia University, New York, NY, USA
| | - Lorisa Simas Teixeira
- https://ror.org/00hj8s172 Department of Biological Sciences, Columbia University, New York, NY, USA
| | | | - Mario Henrique Barros
- https://ror.org/036rp1748 Instituto de Ciências Biomédicas, Universidade de São Paulo, São Paulo, Brasil
| | - Alexander Tzagoloff
- https://ror.org/00hj8s172 Department of Biological Sciences, Columbia University, New York, NY, USA
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2
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Bolotin-Fukuhara M. Thirty years of the HAP2/3/4/5 complex. BIOCHIMICA ET BIOPHYSICA ACTA-GENE REGULATORY MECHANISMS 2017; 1860:543-559. [DOI: 10.1016/j.bbagrm.2016.10.011] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/02/2016] [Revised: 10/24/2016] [Accepted: 10/25/2016] [Indexed: 01/22/2023]
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3
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Woo DK, Phang TL, Trawick JD, Poyton RO. Multiple pathways of mitochondrial-nuclear communication in yeast: Intergenomic signaling involves ABF1 and affects a different set of genes than retrograde regulation. BIOCHIMICA ET BIOPHYSICA ACTA-GENE REGULATORY MECHANISMS 2009; 1789:135-45. [DOI: 10.1016/j.bbagrm.2008.09.008] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/17/2008] [Revised: 09/14/2008] [Accepted: 09/23/2008] [Indexed: 10/21/2022]
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Poyton RO, Dirmeier R, O'Brien K, David P, Dodd A. Experimental Strategies for Analyzing Oxygen Sensing in Yeast. Methods Enzymol 2004; 381:644-62. [PMID: 15063704 DOI: 10.1016/s0076-6879(04)81042-5] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Affiliation(s)
- Robert O Poyton
- Department of Molecular, Cellular, and Developmental Biology, University of Colorado, Boulder 80309-0347, USA
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5
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Schüller HJ. Transcriptional control of nonfermentative metabolism in the yeast Saccharomyces cerevisiae. Curr Genet 2003; 43:139-60. [PMID: 12715202 DOI: 10.1007/s00294-003-0381-8] [Citation(s) in RCA: 331] [Impact Index Per Article: 15.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2002] [Revised: 01/20/2003] [Accepted: 01/21/2003] [Indexed: 11/30/2022]
Abstract
Although sugars are clearly the preferred carbon sources of the yeast Saccharomyces cerevisiae, nonfermentable substrates such as ethanol, glycerol, lactate, acetate or oleate can also be used for the generation of energy and cellular biomass. Several regulatory networks of glucose repression (carbon catabolite repression) are involved in the coordinate biosynthesis of enzymes required for the utilization of nonfermentable substrates. Positively and negatively acting complexes of pleiotropic regulatory proteins have been characterized. The Snf1 (Cat1) protein kinase complex, together with its regulatory subunit Snf4 (Cat3) and alternative beta-subunits Sip1, Sip2 or Gal83, plays an outstanding role for the derepression of structural genes which are repressed in the presence of a high glucose concentration. One molecular function of the Snf1 complex is deactivation by phosphorylation of the general glucose repressor Mig1. In addition to regulation of alternative sugar fermentation, Mig1 also influences activators of respiration and gluconeogenesis, although to a lesser extent. Snf1 is also required for conversion of specific regulatory factors into transcriptional activators. This review summarizes regulatory cis-acting elements of structural genes of the nonfermentative metabolism, together with the corresponding DNA-binding proteins (Hap2-5, Rtg1-3, Cat8, Sip4, Adr1, Oaf1, Pip2), and describes the molecular interactions among general regulators and pathway-specific factors. In addition to the influence of the carbon source at the transcriptional level, mechanisms of post-transcriptional control such as glucose-regulated stability of mRNA are also discussed briefly.
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Affiliation(s)
- Hans-Joachim Schüller
- Institut für Mikrobiologie, Abteilung Genetik und Biochemie, Ernst-Moritz-Arndt-Universität, Jahnstrasse 15a, 17487 Greifswald, Germany.
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Lenka N, Vijayasarathy C, Mullick J, Avadhani NG. Structural organization and transcription regulation of nuclear genes encoding the mammalian cytochrome c oxidase complex. PROGRESS IN NUCLEIC ACID RESEARCH AND MOLECULAR BIOLOGY 1998; 61:309-44. [PMID: 9752724 DOI: 10.1016/s0079-6603(08)60830-2] [Citation(s) in RCA: 102] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
Cytochrome c Oxidase (COX) is the terminal component of the bacterial as well as the mitochondrial respiratory chain complex that catalyzes the conversion of redox energy to ATP. In eukaryotes, the oligomeric enzyme is bound to mitochondrial innermembrane with subunits ranging from 7 to 13. Thus, its biosynthesis involves a coordinate interplay between nuclear and mitochondrial genomes. The largest subunits, I, II, and III, which represent the catalytic core of the enzyme, are encoded by the mitochondrial DNA and are synthesized within the mitochondria. The rest of the smaller subunits implicated in the regulatory function are encoded on the nuclear DNA and imported into mitochondria following their synthesis in the cytosol. Some of the nuclear coded subunits are expressed in tissue and developmental specific isologs. The ubiquitous subunits IV, Va, Vb, VIb, VIc, VIIb, VIIc, and VIII (L) are detected in all the tissues, although the mRNA levels for the individual subunits vary in different tissues. The tissue specific isologs VIa (H), VIIa (H), and VIII (H) are exclusive to heart and skeletal muscle. cDNA sequence analysis of nuclear coded subunits reveals 60 to 90% conservation among species both at the amino acid and nucleotide level, with the exception of subunit VIII, which exhibits 40 to 80% interspecies homology. Functional genes for COX subunits IV, Vb, VIa 'L' & 'H', VIIa 'L' & 'H', VIIc and VIII (H) from different mammalian species and their 5' flanking putative promoter regions have been sequenced and extensively characterized. The size of the genes range from 2 to 10 kb in length. Although the number of introns and exons are identical between different species for a given gene, the size varies across the species. A majority of COX genes investigated, with the exception of muscle-specific COXVIII(H) gene, lack the canonical 'TATAA' sequence and contain GC-rich sequences at the immediate upstream region of transcription start site(s). In this respect, the promoter structure of COX genes resemble those of many house-keeping genes. The ubiquitous COX genes show extensive 5' heterogeneity with multiple transcription initiation sites that bind to both general as well as specialized transcription factors such as YY1 and GABP (NRF2/ets). The transcription activity of the promoter in most of the ubiquitous genes is regulated by factors binding to the 5' upstream Sp1, NRF1, GABP (NRF2), and YY1 sites. Additionally, the murine COXVb promoter contains a negative regulatory region that encompasses the binding motifs with partial or full consensus to YY1, GTG, CArG, and ets. Interestingly, the muscle-specific COX genes contain a number of striated muscle-specific regulatory motifs such as E box, CArG, and MEF2 at the proximal promoter regions. While the regulation of COXVIa (H) gene involves factors binding to both MEF2 and E box in a skeletal muscle-specific fashion, the COXVIII (H) gene is regulated by factors binding to two tandomly duplicated E boxes in both skeletal and cardiac myocytes. The cardiac-specific factor has been suggested to be a novel bHLH protein. Mammalian COX genes provide a valuable system to study mechanisms of coordinated regulation of nuclear and mitochondrial genes. The presence of conserved sequence motifs common to several of the nuclear genes, which encode mitochondrial proteins, suggest a possible regulatory function by common physiological factors like heme/O2/carbon source. Thus, a well-orchestrated regulatory control and cross talks between the nuclear and mitochondrial genomes in response to changes in the mitochondrial metabolic conditions are key factors in the overall regulation of mitochondrial biogenesis.
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Affiliation(s)
- N Lenka
- Department of Animal Biology, School of Veterinary Medicine, University of Pennsylvania, Philadelphia 19104, USA
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Burke PV, Raitt DC, Allen LA, Kellogg EA, Poyton RO. Effects of oxygen concentration on the expression of cytochrome c and cytochrome c oxidase genes in yeast. J Biol Chem 1997; 272:14705-12. [PMID: 9169434 DOI: 10.1074/jbc.272.23.14705] [Citation(s) in RCA: 93] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023] Open
Abstract
Oxygen is an important environmental regulator for the transcription of several genes in Saccharomyces cerevisiae, but it is not yet clear how this yeast or other eukaryotes actually sense oxygen. To begin to address this we have examined the effects of oxygen concentration on the expression of several nuclear genes (CYC1, CYC7, COX4, COX5a, COX5b, COX6, COX7, COX8, and COX9) for proteins of the terminal portion of the respiratory chain. COX5b and CYC7 are hypoxic genes; the rest are aerobic genes. We have found that the level of expression of these genes is determined by oxygen concentration per se and not merely the presence or absence of oxygen and that each of these genes has a low oxygen threshold (0. 5-1 microM O2) for expression. For some aerobic genes (COX4, COX5a, COX7, COX8, and COX9) there is a gradual decline in expression between 200 microM O2 (air) and their oxygen threshold. Below this threshold expression drops precipitously. For others (COX5a and CYC1) the level of expression is nearly constant between 200 microM O2 and their threshold and then drops off. The hypoxic genes COX5b and CYC7 are not expressed until the oxygen concentration is below 0.5 microM O2. These studies have also revealed that COX5a and CYC1, the genes for the aerobic isoforms of cytochrome c oxidase subunit V and cytochrome c, and COX5b and CYC7, the genes for the hypoxic isoforms of cytochrome c oxidase subunit V and cytochrome c, are coexpressed at a variety of oxygen concentrations and switch on or off at extremely low oxygen concentrations. By shifting cells from one oxygen concentration to another we have found that aerobic genes are induced faster than hypoxic genes and that transcripts from both types of gene are turned over quickly. These findings have important implications for cytochrome c oxidase function and biogenesis and for models of oxygen sensing in yeast.
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Affiliation(s)
- P V Burke
- Department of Molecular, Cellular, and Developmental Biology, University of Colorado, Boulder, Colorado 80309-0347, USA
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8
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Haviernik P, Laquin GJ. ACO1 expression in Saccharomyces cerevisiae is regulated by the HAP complex. Folia Microbiol (Praha) 1996; 41:96-8. [PMID: 9090838 DOI: 10.1007/bf02816356] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Affiliation(s)
- P Haviernik
- Department of Biochemistry, Faculty of Science, Comenius University, Bratislava, Slovakia
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9
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Coglievina M, Bertani I, Klima R, Zaccaria P, Bruschi CV. The DNA sequence of a 7941 bp fragment of the left arm of chromosome VII of Saccharomyces cerevisiae contains four open reading frames including the multicopy suppressor gene of the pop2 mutation and a putative serine/threonine protein kinase gene. Yeast 1995; 11:767-74. [PMID: 7668046 DOI: 10.1002/yea.320110808] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023] Open
Abstract
We report the sequence of a 7941 bp DNA fragment from the left arm of chromosome VII of Saccharomyces cerevisiae which contains four open reading frames (ORFs) of greater than 100 amino acid residues. ORF biC834 shows 100% bp identity with the recently identified multicopy suppressor gene of the pop2 mutation (MPT5); its deduced protein product carries an eight-repeat domain region, homologous to that found in the hypothetical regulatory YGL023 protein of S. cerevisiae and the Pumilio protein of Drosophila. ORF biE560 protein exhibits patterns typical of serine/threonine protein kinases, with which it shares high degrees of homology.
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Affiliation(s)
- M Coglievina
- Department of Microbiology, International Centre for Genetic Engineering and Biotechnology, Trieste, Italy
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10
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Fondrat C, Kalogeropoulos A. Approaching the function of new genes by detection of their potential upstream activation sequences in Saccharomyces cerevisiae: application to chromosome III. Curr Genet 1994; 25:396-406. [PMID: 8082184 DOI: 10.1007/bf00351777] [Citation(s) in RCA: 44] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
The systematic sequencing of the yeast genome reveals the presence of many potential genes of unknown function. One way to approach their function is to define which regulatory system controls their transcription. This can also be accomplished by the detection of an upstream activation sequence (UAS). Such a detection can be done by computer, provided that the definition of a UAS includes sufficient and precise rules. We have established such rules for the UASs of the GAL4, RAP1 (RPG box), GCN4, and the HAP2/HAP3/HAP4 regulatory proteins, as well as for a motif (PAC) frequently found upstream of the genes of the RNA polymerase A and C subunits. These rules were applied to the chromosome III DNA sequence, and gave precise predictions.
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Affiliation(s)
- C Fondrat
- Institut de Génétique et Microbiologie, Centre Universitaire d'Orsay, France
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11
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Yamazoe M, Shirahige K, Rashid M, Kaneko Y, Nakayama T, Ogasawara N, Yoshikawa H. A protein which binds preferentially to single-stranded core sequence of autonomously replicating sequence is essential for respiratory function in mitochondrial of Saccharomyces cerevisiae. J Biol Chem 1994. [DOI: 10.1016/s0021-9258(17)36598-5] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022] Open
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12
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Abraham PR, Mulder A, van 't Riet J, Raué HA. Characterization of the Saccharomyces cerevisiae nuclear gene CYB3 encoding a cytochrome b polypeptide of respiratory complex II. MOLECULAR & GENERAL GENETICS : MGG 1994; 242:708-16. [PMID: 8152421 DOI: 10.1007/bf00283426] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Abstract
Computer-assisted structural analysis of the predicted product of the previously described open reading frame (ORF) YKL4 located on the left arm of chromosome XI of Saccharomyces cerevisiae revealed a high degree of similarity (> 50%) to bovine cytochrome b560, the sdhC polypeptide of the Escherichia coli succinate dehydrogenase (SDH) complex and the protein specified by ORF137 located on the chloroplast DNA of Marchantia polymorpha. Disruption of the yeast gene severely impaired mitochondrial function, while Northern analysis showed it to be subject to catabolite repression. Deletion analysis of the CYB3 promoter identified a single HAP2/3/4-binding element that is necessary and sufficient for carbon source-dependent transcriptional regulation. These experiments also suggested the presence of additional, as yet unidentified, transcriptional control elements, both negative and positive. Taken together, these data lead us to conclude that the CYB3 gene encodes the yeast homolog of the bovine cytochrome b560 component of complex II of the mitochondrial electron transport chain.
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Affiliation(s)
- P R Abraham
- Department of Biochemistry and Molecular Biology, BioCentrum Amsterdam, Vrije Universiteit, The Netherlands
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13
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de Winde JH, Grivell LA. Global regulation of mitochondrial biogenesis in Saccharomyces cerevisiae. PROGRESS IN NUCLEIC ACID RESEARCH AND MOLECULAR BIOLOGY 1993; 46:51-91. [PMID: 8234787 DOI: 10.1016/s0079-6603(08)61018-1] [Citation(s) in RCA: 72] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Affiliation(s)
- J H de Winde
- Department of Molecular Cell Biology, University of Amsterdam, The Netherlands
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14
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Keng T, Richard C, Larocque R. Structure and regulation of yeast HEM3, the gene for porphobilinogen deaminase. MOLECULAR & GENERAL GENETICS : MGG 1992; 234:233-43. [PMID: 1508149 DOI: 10.1007/bf00283844] [Citation(s) in RCA: 26] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
Porphobilinogen deaminase is the third enzyme in the heme biosynthetic pathway. hem3 mutants in Saccharomyces cerevisiae are deficient in porphobilinogen deaminase activity. We have isolated the HEM3 gene by complementation of the heme auxotrophy of a hem3 mutant. Sequence analysis reveals an open reading frame of 981 nucleotides. The derived amino acid sequence of the protein encoded by HEM3 shows extensive homology to the reported sequences for porphobilinogen deaminase from a number of other sources, indicating that HEM3 is the structural gene for porphobilinogen deaminase. Earlier reports have suggested that expression of HEM3 is induced by porphobilinogen, the substrate of the encoded enzyme. We have investigated the transcription of HEM3 and have found that it is not affected by the ability of the cell to make porphobilinogen or heme. However, we have found that HAP2 and HAP3 gene products are involved in the expression of HEM3. An important element required for expression of HEM3 has been localized to a small region that contains a sequence homologous to the HAP2-3-4 binding sites of several genes including HEM1. These findings suggest that HEM3 expression is regulated in the same manner as that of HEM1 which encodes the first enzyme of the heme biosynthetic pathway.
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Affiliation(s)
- T Keng
- Department of Microbiology and Immunology, McGill University, Montreal, Quebec, Canada
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15
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Oechsner U, Hermann H, Zollner A, Haid A, Bandlow W. Expression of yeast cytochrome c1 is controlled at the transcriptional level by glucose, oxygen and haem. MOLECULAR & GENERAL GENETICS : MGG 1992; 232:447-59. [PMID: 1316998 DOI: 10.1007/bf00266250] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
The nuclear gene for cytochrome c1 in Saccharomyces cerevisiae (CYT1) was localized on chromosome XV. Its upstream region was identified by functional complementation. Fusion to the lacZ reporter gene on a CEN plasmid allowed study of the effect of carbon sources and of specific deletion mutations on expression of the gene in yeast transformants. Detailed promoter analysis combined with expression studies in recipient strains defective in regulatory genes identified cis-acting sites and transcription factors involved in the regulated expression of the cytochrome c1 gene. These analyses showed that, in the presence of glucose, transcription of CYT1 is positively controlled by oxygen, presumably through the haem signal, and mediated by the HAP1-encoded transactivator. It is additionally regulated by the HAP2/3/4 complex which mediates gene activation mainly under glucose-free conditions. Basal transcription is, in part, effected by CPF1, a centromere and promoter-binding factor.
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MESH Headings
- Base Sequence
- Binding Sites
- Chromosome Deletion
- Chromosome Mapping
- Chromosomes, Fungal
- Cloning, Molecular
- Cytochromes c1/genetics
- Cytochromes c1/metabolism
- DNA, Fungal/genetics
- DNA, Fungal/isolation & purification
- Gene Expression Regulation, Fungal/drug effects
- Genes, Fungal
- Genes, Regulator
- Glucose/pharmacology
- Heme/pharmacology
- Molecular Sequence Data
- Oxygen/pharmacology
- Promoter Regions, Genetic
- Recombinant Fusion Proteins/metabolism
- Regulatory Sequences, Nucleic Acid
- Saccharomyces cerevisiae/drug effects
- Saccharomyces cerevisiae/genetics
- Saccharomyces cerevisiae/metabolism
- Sequence Homology, Nucleic Acid
- Transcription Factors/metabolism
- Transcription, Genetic/drug effects
- Transcriptional Activation
- beta-Galactosidase/genetics
- beta-Galactosidase/metabolism
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Affiliation(s)
- U Oechsner
- Institut für Genetik und Mikrobiologie, München, FRG
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16
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Bowman SB, Zaman Z, Collinson LP, Brown AJ, Dawes IW. Positive regulation of the LPD1 gene of Saccharomyces cerevisiae by the HAP2/HAP3/HAP4 activation system. MOLECULAR & GENERAL GENETICS : MGG 1992; 231:296-303. [PMID: 1310523 DOI: 10.1007/bf00279803] [Citation(s) in RCA: 36] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
The LPD1 gene of Saccharomyces cerevisiae, encoding lipoamide dehydrogenase (LPDH), is subject to catabolite repression. The promoter of this gene contains a number of motifs for DNA-binding transcriptional activators, including three which show strong sequence homology to the core HAP2/HAP3/HAP4 binding motif. Here we report that transcription of LPD1 requires HAP2, HAP3 and HAP4 for release from glucose repression. In the wild-type strain, specific activity of LPDH was increased 12-fold by growth on lactate, 10-fold on glycerol and four- to five-fold on galactose or raffinose, compared to growth on glucose. In hap2, hap3 and hap4 null mutants, the specific activities of LPDH in cultures grown on galactose and raffinose showed only slight induction above the basal level on glucose medium. Similar results were obtained upon assaying for beta-galactosidase production in wild-type, or hap2, hap3 or hap4 mutant strains carrying a single copy of the LPD1 promoter fused in frame to the lacZ gene of Escherichia coli and integrated at the URA3 locus. Transcript analysis in wild-type and hap2 mutants confirmed that the HAP2 protein regulates LPD1 expression at the level of transcription in the same way as it does for the CYC1 gene. Site-directed mutagenesis of the putative HAP2/HAP3/HAP4 binding site at -204 relative to the ATG start codon showed that this element was required for full derepression of the LPD1 gene on non-fermentable substrates.
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Affiliation(s)
- S B Bowman
- School of Biochemistry, University of New South Wales, Kensington, Australia
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17
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Structural organization of nuclear gene for subunit Vb of mouse mitochondrial cytochrome c oxidase. J Biol Chem 1991. [DOI: 10.1016/s0021-9258(18)98637-0] [Citation(s) in RCA: 22] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
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18
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Carter RS, Avadhani NG. Cloning and characterization of the mouse cytochrome c oxidase subunit IV gene. Arch Biochem Biophys 1991; 288:97-106. [PMID: 1654830 DOI: 10.1016/0003-9861(91)90169-j] [Citation(s) in RCA: 26] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
cDNA for mouse cytochrome c oxidase subunit IV (COXIV) was isolated by screening mouse liver and kidney cDNA libraries with a bovine COXIV cDNA probe. The 679-nucleotide nearly full length cDNA codes for a 22-amino acid presequence and a 147-amino acid mature protein which show 77 to 95% positional identity with the predicted sequences of human, bovine, and rat subunits. Screening of mouse genomic lambda EMBL3 library using the mouse cDNA probe yielded two overlapping clones. Restriction mapping and sequencing of the clones show that the mouse COXIV mRNA sequences are contained in five exons ranging from 58 to 236 base pairs, and four introns in a 7-kilobase region of the mouse genome. Southern blot analysis of restriction-digested genomic DNA indicates the presence of a single gene for COXIV in the mouse genome. Primer extension analysis using a synthetic 22-mer oligonucleotide, together with the 0.68-kilobase size of the mRNA shown by the Northern blot analysis, indicates that the major transcription start site of the COXIV gene is located 59 nucleotides upstream of the translation start site. The COXIV gene is highly GC rich and lacks TATA and CAAT elements in the immediate upstream region of the transcription start site. The putative promoter region, however, contains a number of GC boxes similar to those involved in the binding of Sp1 transcription factor. The unique features of the gene, as well as its characteristics common to other nuclear genes coding for different mitochondrial proteins, have been discussed.
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Affiliation(s)
- R S Carter
- Department of Animal Biology, School of Veterinary Medicine, University of Pennsylvania, Philadelphia 19104-6046
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