FRINK Linked Data Fragments server

Matches in SemOpenAlex for { <https://semopenalex.org/work/W3008825692> ?p ?o ?g. }

• W3008825692 endingPage "5109" @default.
• W3008825692 startingPage "5095" @default.
• W3008825692 abstract "Heme (iron protoporphyrin IX) is a well-known prosthetic group for enzymes involved in metabolic pathways such as oxygen transport and electron transfer through the mitochondrial respiratory chain. However, heme has also been shown to be an important regulatory molecule (as “labile” heme) for diverse processes such as translation, kinase activity, and transcription in mammals, yeast, and bacteria. Taking advantage of a yeast strain deficient for heme production that enabled controlled modulation and monitoring of labile heme levels, here we investigated the role of labile heme in the regulation of mitochondrial biogenesis. This process is regulated by the HAP complex in yeast. Using several biochemical assays along with EM and epifluorescence microscopy, to the best of our knowledge, we show for the first time that cellular labile heme is critical for the post-translational regulation of HAP complex activity, most likely through the stability of the transcriptional co-activator Hap4p. Consequently, we found that labile heme regulates mitochondrial biogenesis and cell growth. The findings of our work highlight a new mechanism in the regulation of mitochondrial biogenesis by cellular metabolites. Heme (iron protoporphyrin IX) is a well-known prosthetic group for enzymes involved in metabolic pathways such as oxygen transport and electron transfer through the mitochondrial respiratory chain. However, heme has also been shown to be an important regulatory molecule (as “labile” heme) for diverse processes such as translation, kinase activity, and transcription in mammals, yeast, and bacteria. Taking advantage of a yeast strain deficient for heme production that enabled controlled modulation and monitoring of labile heme levels, here we investigated the role of labile heme in the regulation of mitochondrial biogenesis. This process is regulated by the HAP complex in yeast. Using several biochemical assays along with EM and epifluorescence microscopy, to the best of our knowledge, we show for the first time that cellular labile heme is critical for the post-translational regulation of HAP complex activity, most likely through the stability of the transcriptional co-activator Hap4p. Consequently, we found that labile heme regulates mitochondrial biogenesis and cell growth. The findings of our work highlight a new mechanism in the regulation of mitochondrial biogenesis by cellular metabolites. Mitochondria are organelles that have a critical role in the energy and intermediary metabolism in eukaryotic cells. They are well-known for their involvement in the synthesis of ATP, the currency in charge of fulfilling cell energy demand. Mitochondrial ATP synthesis mostly relies on the oxidative phosphorylation system (OXPHOS), 3The abbreviations used are: OXPHOSoxidative phosphorylationHAPheme activator proteinmtDNAmitochondrial DNAPGC-1PPARγ coactivator-1DP IXdeuteroporphyrin IXPGK1phosphoglycerate kinase 1DTNB5,5′-dithiobis(2-nitrobenzoic acid)GSTGSH S-transferaseALAδ-aminolevulinateHEM1δ-aminolevulinate synthaseODoptical densityBis-Tris2-[bis(2-hydroxyethyl)amino]-2-(hydroxymethyl)propane-1,3-diol. which involves enzymatic complexes that form the mitochondrial respiratory chain and the phosphorylation system. It is well-established that mitochondrial enzymatic content within cells varies to match ATP synthesis to ATP demand. This phenomenon has been observed in different species and experimental models, ranging from microorganisms, such as yeast, to mammals, and is associated with diverse pathologies (1Holloszy J. Effects of exercise on mitochondrial oxygen uptake and respiratory enzyme activity in skeletal muscle.J. Biol. Chem. 1967; 242 (4290225): 2278-2282Abstract Full Text PDF PubMed Google Scholar, 2Dejean L. Beauvoit B. Guérin B. Rigoulet M. Growth of the yeast Saccharomyces cerevisiae on a non-fermentable substrate: control of energetic yield by the amount of mitochondria.Biochim. Biophys. Acta. 2000; 1457 (10692549): 45-5610.1016/S0005-2728(00)00053-0Crossref PubMed Scopus (40) Google Scholar, 3Devin A. Dejean L. Beauvoit B. Chevtzoff C. Avéret N. Bunoust O. Rigoulet M. Growth yield homeostasis in respiring yeast is due to a strict mitochondrial content adjustment.J. Biol. Chem. 2006; 281 (16849319): 26779-2678410.1074/jbc.M604800200Abstract Full Text Full Text PDF PubMed Scopus (22) Google Scholar, 4Kelley D.E. He J. Menshikova E.V. Ritov V.B. Dysfunction of mitochondria in human skeletal muscle in type 2 diabetes.Diabetes. 2002; 51 (12351431): 2944-295010.2337/diabetes.51.10.2944Crossref PubMed Scopus (1694) Google Scholar, 5Bonnard C. Durand D. Peyrol S. Chanseaume E. Chauvin M.A. Morio B. Vidal H. Rieusset J. Mitochondrial dysfunction results from oxidative stress in the skeletal muscle of diet-induced insulin resistant mice.J. Clin. Invest. 2008; 118 (18188455): 789-80010.1172/JCI32601Crossref PubMed Scopus (626) Google Scholar, 6Devin A. Rigoulet M. Mechanisms of mitochondrial response to variations in energy demand in eukaryotic cells: mechanisms of mitochondrial response to variations in energy demand in eukaryotic cells.Am. J. Physiol. Cell Physiol. 2007; 292 (16943247): C52-C5810.1152/ajpcell.00208.2006Crossref PubMed Scopus (58) Google Scholar). oxidative phosphorylation heme activator protein mitochondrial DNA PPARγ coactivator-1 deuteroporphyrin IX phosphoglycerate kinase 1 5,5′-dithiobis(2-nitrobenzoic acid) GSH S-transferase δ-aminolevulinate δ-aminolevulinate synthase optical density 2-[bis(2-hydroxyethyl)amino]-2-(hydroxymethyl)propane-1,3-diol. Although mitochondria possess their own genome (mtDNA), they are genetically semiautonomous. Indeed, the mtDNA encodes a few (8 in yeast and 13 in mammals) of the numerous proteins constituting the OXPHOS. All of the remaining OXPHOS components and mitochondrial proteins (protein machineries involved in mtDNA replication, transcription and translation, assembly factors, mitochondrial protein import, and intermediary metabolism) are encoded by the nuclear genome. Thus, regulation of the expression of both mitochondrial and nuclear genes encoding mitochondrial proteins is controlled by a defined network of nuclear transcription factors. In the yeast Saccharomyces cerevisiae, the transcription factors Hap2p/3p/4p/5p (HAP complex) are the master regulators of mitochondrial biogenesis (7Lascaris R. Bussemaker H.J. Boorsma A. Piper M. van der Spek H. Grivell L. Blom J. Hap4p overexpression in glucose-grown Saccharomyces cerevisiae induces cells to enter a novel metabolic state.Genome Biol. 2003; 4 (12537548): R310.1186/gb-2002-4-1-r3Crossref PubMed Google Scholar, 8Buschlen S. Amillet J.M. Guiard B. Fournier A. Marcireau C. Bolotin-Fukuhara M. The S. cerevisiae HAP complex, a key regulator of mitochondrial function, coordinates nuclear and mitochondrial gene expression.Comp. Funct. Genomics. 2003; 4 (18629096): 37-4610.1002/cfg.254Crossref PubMed Scopus (71) Google Scholar). This heteromeric complex relies on the binding to the promoter of target genes by the DNA-binding subcomplex Hap2p/Hap3p/Hap5p. These three subunits are constitutively expressed. The activation of transcription is mediated by Hap4p, the co-activator subunit (9Pinkham J.L. Guarente L. Cloning and molecular analysis of the HAP2 locus: a global regulator of respiratory genes in Saccharomyces cerevisiae.Mol. Cell. Biol. 1985; 5 (3915775): 3410-341610.1128/MCB.5.12.3410Crossref PubMed Scopus (93) Google Scholar, 10Hahn S. Pinkham J. Wei R. Miller R. Guarente L. The HAP3 regulatory locus of Saccharomyces cerevisiae encodes divergent overlapping transcripts.Mol. Cell. Biol. 1988; 8 (2832732): 655-66310.1128/MCB.8.2.655Crossref PubMed Scopus (87) Google Scholar, 11Forsburg S.L. Guarente L. Identification and characterization of HAP4: a third component of the CCAAT-bound HAP2/HAP3 heteromer.Genes Dev. 1989; 3 (2676721): 1166-117810.1101/gad.3.8.1166Crossref PubMed Scopus (305) Google Scholar, 12McNabb D.S. Xing Y. Guarente L. Cloning of yeast HAP5: a novel subunit of a heterotrimeric complex required for CCAAT binding.Genes Dev. 1995; 9 (7828851): 47-5810.1101/gad.9.1.47Crossref PubMed Scopus (231) Google Scholar, 13McNabb D.S. Pinto I. Assembly of the Hap2p/Hap3p/Hap4p/Hap5p-DNA Complex in Saccharomyces cerevisiae.Eukaryot. Cell. 2005; 4 (16278450): 1829-183910.1128/EC.4.11.1829-1839.2005Crossref PubMed Scopus (62) Google Scholar) and the only subunit whose expression is known to be regulated by the carbon source. Deletion of any of the subunits of the HAP complex impairs yeast growth on nonfermentable substrate, such as lactate, on which mitochondria are the only source of ATP production (11Forsburg S.L. Guarente L. Identification and characterization of HAP4: a third component of the CCAAT-bound HAP2/HAP3 heteromer.Genes Dev. 1989; 3 (2676721): 1166-117810.1101/gad.3.8.1166Crossref PubMed Scopus (305) Google Scholar). In mammals, due to multicellular organization, more transcriptional regulators are involved, although the general mechanism is the same, with the well-known co-activator PGC-1α acting like a functional counterpart of the yeast Hap4p (14Scarpulla R.C. Vega R.B. Kelly D.P. Transcriptional integration of mitochondrial biogenesis.Trends Endocrinol. Metab. 2012; 23 (22817841): 459-46610.1016/j.tem.2012.06.006Abstract Full Text Full Text PDF PubMed Scopus (521) Google Scholar, 15Wu Z. Puigserver P. Andersson U. Zhang C. Adelmant G. Mootha V. Troy A. Cinti S. Lowell B. Scarpulla R.C. Spiegelman B.M. Mechanisms controlling mitochondrial biogenesis and respiration through the thermogenic coactivator PGC-1.Cell. 1999; 98 (10412986): 115-12410.1016/S0092-8674(00)80611-XAbstract Full Text Full Text PDF PubMed Scopus (3045) Google Scholar). Extensive work is still being carried out to identify the molecular regulators of the activity of PGC-1α and Hap4p. In this regard, it is interesting to point out recent results that highlight that both the yeast and mammalian co-activators share common regulatory signals. For example, it has been recently demonstrated that PGC-1α is regulated by the GSH redox state, as we previously showed for Hap4p (16Yoboue E.D. Augier E. Galinier A. Blancard C. Pinson B. Casteilla L. Rigoulet M. Devin A. cAMP-induced mitochondrial compartment biogenesis: role of glutathione redox state.J. Biol. Chem. 2012; 287 (22396541): 14569-1457810.1074/jbc.M111.302786Abstract Full Text Full Text PDF PubMed Scopus (17) Google Scholar, 17Aquilano K. Baldelli S. Pagliei B. Cannata S.M. Rotilio G. Ciriolo M.R. p53 orchestrates the PGC-1α-mediated antioxidant response upon mild redox and metabolic imbalance.Antioxid. Redox Signal. 2013; 18 (22861165): 386-39910.1089/ars.2012.4615Crossref PubMed Scopus (120) Google Scholar). Previous studies also established the involvement of reactive oxygen species and cAMP-dependent signaling in negative and positive regulation of the transcriptional regulators of mitochondrial biogenesis in both yeast and mammals (5Bonnard C. Durand D. Peyrol S. Chanseaume E. Chauvin M.A. Morio B. Vidal H. Rieusset J. Mitochondrial dysfunction results from oxidative stress in the skeletal muscle of diet-induced insulin resistant mice.J. Clin. Invest. 2008; 118 (18188455): 789-80010.1172/JCI32601Crossref PubMed Scopus (626) Google Scholar, 18Dejean L. Beauvoit B. Alonso A.P. Bunoust O. Guérin B. Rigoulet M. cAMP-induced modulation of the growth yield of Saccharomyces cerevisiae during respiratory and respiro-fermentative metabolism.Biochim. Biophys. Acta. 2002; 1554 (12160989): 159-16910.1016/S0005-2728(02)00240-2Crossref PubMed Scopus (30) Google Scholar, 19Bogacka I. Ukropcova B. McNeil M. Gimble J.M. Smith S.R. Structural and functional consequences of mitochondrial biogenesis in human adipocytes in vitro.J. Clin. Endocrinol. Metab. 2005; 90 (16204368): 6650-665610.1210/jc.2005-1024Crossref PubMed Scopus (116) Google Scholar, 20Chevtzoff C. Yoboue E.D. Galinier A. Casteilla L. Daignan-Fornier B. Rigoulet M. Devin A. Reactive oxygen species-mediated regulation of mitochondrial biogenesis in the yeast Saccharomyces cerevisiae.J. Biol. Chem. 2010; 285 (19897478): 1733-174210.1074/jbc.M109.019570Abstract Full Text Full Text PDF PubMed Scopus (40) Google Scholar, 21Yoboue E.D. Devin A. Reactive oxygen species-mediated control of mitochondrial biogenesis.Int. J. Cell Biol. 2012; 2012 (22693510): 40387010.1155/2012/403870Crossref PubMed Scopus (44) Google Scholar). Heme (iron protoporphyrin IX) is well-known as a prosthetic group for enzymes involved in the metabolic pathway, such as oxygen transport and electron transfer through the mitochondrial respiratory chain. However, heme has also been shown to be an important regulatory molecule (“labile” heme) for diverse processes, such as translation, kinase activity, and transcription in mammals, yeast, and bacteria (22Qi Z. Hamza I. O'Brian M.R. Heme is an effector molecule for iron-dependent degradation of the bacterial iron response regulator (Irr) protein.Proc. Natl. Acad. Sci. U.S.A. 1999; 96 (10557272): 13056-1306110.1073/pnas.96.23.13056Crossref PubMed Scopus (142) Google Scholar, 23Mense S.M. Zhang L. Heme: a versatile signaling molecule controlling the activities of diverse regulators ranging from transcription factors to MAP kinases.Cell Res. 2006; 16 (16894358): 681-69210.1038/sj.cr.7310086Crossref PubMed Scopus (200) Google Scholar, 24Chen J.J. Regulation of protein synthesis by the heme-regulated eIF2α kinase: relevance to anemias.Blood. 2007; 109 (17110456): 2693-269910.1182/blood-2006-08-041830Crossref PubMed Scopus (227) Google Scholar). Moreover, the hypothesis that heme can be a regulatory molecule for the HAP complex has been previously formulated (11Forsburg S.L. Guarente L. Identification and characterization of HAP4: a third component of the CCAAT-bound HAP2/HAP3 heteromer.Genes Dev. 1989; 3 (2676721): 1166-117810.1101/gad.3.8.1166Crossref PubMed Scopus (305) Google Scholar, 25Trawick J.D. Wright R.M. Poyton R.O. Transcription of yeast COX6, the gene for cytochrome c oxidase subunit VI, is dependent of heme and on the HAP2 gene.J. Biol. Chem. 1989; 264 (2540169): 7005-7008Abstract Full Text PDF PubMed Google Scholar, 26Betina S. Gavurníková G. Haviernik P. Šabová L Kolarov J. Expression of the AAC2 gene encoding the major mitochondrial ADP/ATP carrier in Saccharomyces cerevisiae is controlled at the transcriptional level by oxygen, heme and HAP2 factor.Eur. J. Biochem. 1995; 229 (7758459): 651-65710.1111/j.1432-1033.1995.tb20510.xCrossref PubMed Scopus (30) Google Scholar, 27Bourens M. Fontanesi F. Soto I.C. Liu J. Barrientos A. Redox and reactive oxygen species regulation of mitochondrial cytochrome c oxidase biogenesis.Antioxid. Redox Signal. 2013; 19 (22937827): 1940-195210.1089/ars.2012.4847Crossref PubMed Scopus (41) Google Scholar). However, no study has been able to establish molecular details surrounding heme regulation of the HAP complex, although a heme-dependent regulation of Hap4p transcription has been described recently (28Hon T. Lee H.C. Hu Z. Iyer V.R. Zhang L. The heme activator protein Hap1 represses transcription by a heme-independent mechanism in Saccharomyces cerevisiae.Genetics. 2005; 169 (15654089): 1343-135210.1534/genetics.104.037143Crossref PubMed Scopus (32) Google Scholar, 29Lan C. Lee H.C. Tang S. Zhang L. A novel mode of chaperone action.J. Biol. Chem. 2004; 279 (15102838): 27607-2761210.1074/jbc.M402777200Abstract Full Text Full Text PDF PubMed Scopus (46) Google Scholar, 30Lee H.C. Hon T. Lan C. Zhang L. Structural environment dictates the biological significance of heme-responsive motifs and the role of Hsp90 in the activation of the heme activator protein Hap1.Mol. Cell. Biol. 2003; 23 (12897155): 5857-586610.1128/MCB.23.16.5857-5866.2003Crossref PubMed Scopus (30) Google Scholar, 31Lee H.C. Hon T. Zhang L. The molecular chaperone Hsp90 mediates heme activation of the yeast transcriptional activator Hap1.J. Biol. Chem. 2002; 277 (11751848): 7430-743710.1074/jbc.M106951200Abstract Full Text Full Text PDF PubMed Scopus (29) Google Scholar, 32Zhang T. Bu P. Zeng J. Vancura A. Increased heme synthesis in yeast induces a metabolic switch from fermentation to respiration even under conditions of glucose repression.J. Biol. Chem. 2017; 292 (28830930): 16942-1695410.1074/jbc.M117.790923Abstract Full Text Full Text PDF PubMed Scopus (31) Google Scholar). Thus, although the name HAP historically stands for “heme activator protein,” the HAP complex is sometimes designated like a heme-independent transcription factor (33Liu Z. Butow R. A transcriptional switch in the expression of yeast tricarboxylic acid cycle genes in response to a reduction or loss of respiratory function.Mol. Cell. Biol. 1999; 19 (10490611): 6720-672810.1128/MCB.19.10.6720Crossref PubMed Scopus (203) Google Scholar). Taking advantage of a yeast strain deficient for heme production, we tackled this question. Our results are the first to show that cellular labile heme is critical for the HAP complex activity, most likely through an enhancement of the stability of the co-activator Hap4p. Consequently, labile heme regulates mitochondrial biogenesis and cell growth. This work represents a new contribution to the field of mitochondrial biogenesis regulation by cell metabolites. Our cell growth experiments were carried out on a nonfermentable substrate: lactate. In this condition, the mitochondrial compartment is well-differentiated, and mitochondrial oxidative phosphorylation processes and the HAP complex are mandatory for cell growth and proliferation. The heme biosynthesis pathway is localized within two distinct compartments: the mitochondria and the cytosol (Scheme 1). To modulate the cellular labile heme pool, we made use of a strain deleted for the first enzyme of this pathway: Hem1p. This enzyme, which is localized in the mitochondrial matrix, catalyzes the condensation of glycine with succinyl-CoA to generate δ-aminolevulinate (ALA). A strain deleted for this enzyme is auxotrophic for ALA (35Thorsness M. Schafer W. D'Ari L. Rine J. Positive and negative transcriptional control by heme of genes encoding 3-hydroxy-3-methylglutaryl coenzyme A reductase in Saccharomyces cerevisiae.Mol. Cell. Biol. 1989; 9 (2685574): 5702-571210.1128/MCB.9.12.5702Crossref PubMed Scopus (76) Google Scholar). In an attempt to modulate cellular labile heme, the Δhem1 strain was supplemented with increasing concentrations of ALA, and the cellular labile heme pool was assessed thanks to the reliable HMG2-lacZ reporter gene (35Thorsness M. Schafer W. D'Ari L. Rine J. Positive and negative transcriptional control by heme of genes encoding 3-hydroxy-3-methylglutaryl coenzyme A reductase in Saccharomyces cerevisiae.Mol. Cell. Biol. 1989; 9 (2685574): 5702-571210.1128/MCB.9.12.5702Crossref PubMed Scopus (76) Google Scholar, 36Crisp R.J. Pollington A. Galea C. Jaron S. Yamaguchi-Iwai Y. Kaplan J. Inhibition of heme biosynthesis prevents transcription of iron uptake genes in yeast.J. Biol. Chem. 2003; 278 (12928433): 45499-4550610.1074/jbc.M307229200Abstract Full Text Full Text PDF PubMed Scopus (73) Google Scholar). In this system, expression of the β-gal is under the regulation of the HMG2 promoter, which is strongly repressed by the heme level. Fig. 1 shows that whereas this promoter's activity is low in WT cells, this activity is strongly increased in Δhem1 cells grown in the presence of low (5 and 10 μg/ml) ALA concentrations. Increasing extracellular ALA concentrations lead to a decrease in this promoter's activity. This shows that modulation of extracellular ALA in a Δhem1 strain allows modulation of the cellular labile heme pool. Extracellular ALA concentration above 100 μg/ml in both WT and Δhem1 cells did not increase the repression of HMG2-lacZ reporter gene (data not shown).Figure 1Assessment of the labile heme level through the activity of HMG2 promoter-lacZ gene at different concentrations of ALA. WT and Δhem1 cells were transformed with a plasmid encoding the reporter gene HMG2-LacZ, which is negatively regulated by labile heme. The growth medium of Δhem1 cells was supplemented with 5 μg·ml−1 (Δhem1-ALA5-), 10 μg·ml−1 (Δhem1-ALA10-), 25 μg·ml−1 (Δhem1-ALA25-), or 100 μg·ml−1 (Δhem1-ALA100-) ALA. Cells were harvested, and β-gal activities were measured and expressed as a percentage of WT. Results shown represent means ± S.D. (error bars) of at least three separate experiments. *, p < 0.05; ***, p < 0.001; ****, p < 0.0001.View Large Image Figure ViewerDownload Hi-res image Download (PPT) As stipulated above, cells were grown on nonfermentable substrate, where growth is strictly dependent on mitochondrial activity (i.e. energy conversion processes (ATP synthesis) take place at the mitochondrial level). Further, mitochondrial oxidative phosphorylation requires heme biosynthesis to generate mitochondrial cytochromes. We thus investigated mitochondrial activities in Δhem1 cells supplemented with various concentrations of ALA. Fig. 2A shows that there is a 50% decrease in Δhem1-ALA5- cellular respiratory rate compared with the WT cells. Increasing extracellular ALA up to 100 μg/ml allowed a full restoration of the cellular respiratory rate. Fig. 2B shows that this modulation of the cellular respiratory rate affected the cellular growth rate, and the relationship between these two parameters is linear (Fig. 2B, inset), as shown previously (3Devin A. Dejean L. Beauvoit B. Chevtzoff C. Avéret N. Bunoust O. Rigoulet M. Growth yield homeostasis in respiring yeast is due to a strict mitochondrial content adjustment.J. Biol. Chem. 2006; 281 (16849319): 26779-2678410.1074/jbc.M604800200Abstract Full Text Full Text PDF PubMed Scopus (22) Google Scholar). In addition, Fig. 2C shows that the activity of cytochrome c oxidase (one of the most controlling enzymes of the oxidative phosphorylation system (37Groen A.K. Wanders R.J.A. Westerhoff H.V. van der Meer R. Tager J.M. Quantification of the contribution of various steps to the control of mitochondrial respiration.J. Biol. Chem. 1982; 257 (7061448): 2754-2757Abstract Full Text PDF PubMed Google Scholar, 38Tager J.M. Wanders R.J.A. Groen A.K. Kunz W. Bohnensack R. Küster U. Letko G. Böhme G. Duszynski J. Wojtczak L. Control of mitochondrial respiration.FEBS Lett. 1983; 151 (6337871): 1-910.1016/0014-5793(83)80330-5Crossref PubMed Scopus (154) Google Scholar, 39Brown G.C. Control of respiration and ATP synthesis in mammalian mitochondria and cells.Biochem. J. 1992; 284 (1599389): 1-1310.1042/bj2840001Crossref PubMed Scopus (493) Google Scholar)) exhibits a 50% decrease in Δhem1-ALA5- compared with the WT cells. Increasing extracellular ALA up to 100 μg/ml allows a full restoration of this activity. Furthermore, cytochrome c oxidase activity perfectly correlates with respiratory rate (Fig. 2C, inset). The above-mentioned results relate to the oxidative phosphorylation amount/activity. To determine whether we observed an overall quantitative regulation of the mitochondrial compartment, we assessed citrate synthase activity, a well-accepted marker of mitochondrial amount within cells (40Mogensen M. Bagger M. Pedersen P.K. Fernström M. Sahlin K. Cycling efficiency in humans is related to low UCP3 content and to type I fibres but not to mitochondrial efficiency.J. Physiol. 2006; 571 (16423857): 669-68110.1113/jphysiol.2005.101691Crossref PubMed Scopus (133) Google Scholar, 41Larsen S. Nielsen J. Hansen C.N. Nielsen L.B. Wibrand F. Stride N. Schroder H.D. Boushel R. Helge J.W. Dela F. Hey-Mogensen M. Biomarkers of mitochondrial content in skeletal muscle of healthy young human subjects.J. Physiol. 2012; 590 (22586215): 3349-336010.1113/jphysiol.2012.230185Crossref PubMed Scopus (670) Google Scholar, 42Rabøl R. Svendsen P.F. Skovbro M. Boushel R. Haugaard S.B. Schjerling P. Schrauwen P. Hesselink M.K.C. Nilas L. Madsbad S. Dela F. Reduced skeletal muscle mitochondrial respiration and improved glucose metabolism in nondiabetic obese women during a very low calorie dietary intervention leading to rapid weight loss.Metabolism. 2009; 58 (19454354): 1145-115210.1016/j.metabol.2009.03.014Abstract Full Text Full Text PDF PubMed Scopus (54) Google Scholar). Fig. 2D shows that there is a 60% decrease in Δhem1-ALA5- citrate synthase activity compared with the WT cells. Increasing extracellular ALA up to 100 μg/ml allows a full restoration of citrate synthase activity. The inset in Fig. 2D shows a very good correlation between respiratory rate and citrate synthase activity, reinforcing the hypothesis of an overall regulation of the mitochondrial compartment upon the addition of ALA in Δhem1 cells. Within the cell, mitochondria are highly dynamic organelles that form a network. They undergo fusion and fission events continuously, leading to a diverse range of mitochondrial morphologies, from fragmented states to continuous networks (43McBride H.M. Neuspiel M. Wasiak S. Mitochondria: more than just a powerhouse.Curr. Biol. 2006; 16 (16860735): R551-R56010.1016/j.cub.2006.06.054Abstract Full Text Full Text PDF PubMed Scopus (1301) Google Scholar, 44Hoppins S. Lackner L. Nunnari J. The machines that divide and fuse mitochondria.Annu. Rev. Biochem. 2007; 76 (17362197): 751-78010.1146/annurev.biochem.76.071905.090048Crossref PubMed Scopus (588) Google Scholar, 45Cerveny K.L. Tamura Y. Zhang Z. Jensen R.E. Sesaki H. Regulation of mitochondrial fusion and division.Trends Cell Biol. 2007; 17 (17959383): 563-56910.1016/j.tcb.2007.08.006Abstract Full Text Full Text PDF PubMed Scopus (180) Google Scholar). It remains unclear how the diverse morphologies interact with bioenergetic properties. To determine whether the mitochondrial structure/network was altered when mitochondrial oxidative phosphorylation activities decreased, we performed both fluorescence and electronic microscopy under our experimental conditions. Fig. 3A shows that when visualized in fluorescence microscopy, mitochondria exhibit a well-differentiated network, comparable with that of the WT for any of the extracellular ALA concentrations tested. Fig. 3B shows that when visualized in EM, mitochondria exhibit a coherent ultrastructure, comparable with that of the WT for any of the extracellular ALA concentration tested. However, for the lowest (Δhem1-ALA5- and Δhem1-ALA10-) ALA concentrations, a decrease in mitochondrial diameter was observed. For higher ALA concentrations, the mitochondrial diameter was comparable with that of the WT. The amount of mitochondria within a cell is controlled by its turnover (i.e. the respective rates of mitochondrial biogenesis and mitochondrial degradation). The HAP complex has been shown to be involved in the specific induction of genes involved in gluconeogenesis, metabolism of alternate carbon sources, respiration, and mitochondrial development. The disruption of any subunit of this complex renders the cells unable to grow on nonfermentable carbon sources (10Hahn S. Pinkham J. Wei R. Miller R. Guarente L. The HAP3 regulatory locus of Saccharomyces cerevisiae encodes divergent overlapping transcripts.Mol. Cell. Biol. 1988; 8 (2832732): 655-66310.1128/MCB.8.2.655Crossref PubMed Scopus (87) Google Scholar, 12McNabb D.S. Xing Y. Guarente L. Cloning of yeast HAP5: a novel subunit of a heterotrimeric complex required for CCAAT binding.Genes Dev. 1995; 9 (7828851): 47-5810.1101/gad.9.1.47Crossref PubMed Scopus (231) Google Scholar, 46Olesen J. Hahn S. Guarente L. Yeast HAP2 and HAP3 activators both bind to the CYC1 upstream activation site, UAS2, in an interdependent manner.Cell. 1987; 51 (2826015): 953-96110.1016/0092-8674(87)90582-4Abstract Full Text PDF PubMed Scopus (152) Google Scholar, 47Forsburg S.L. Guarente L. Mutational analysis of upstream activation sequence 2 of the CYC1 gene of Saccharomyces cerevisiae: a HAP2-HAP3-responsive site.Mol. Cell. Biol. 1988; 8 (2832731): 647-65410.1128/MCB.8.2.647Crossref PubMed Scopus (84) Google Scholar). Moreover, many genes involved in energy metabolism have been shown to be regulated by this complex (8Buschlen S. Amillet J.M. Guiard B. Fournier A. Marcireau C. Bolotin-Fukuhara M. The S. cerevisiae HAP complex, a key regulator of mitochondrial function, coordinates nuclear and mitochondrial gene expression.Comp. Funct. Genomics. 2003; 4 (18629096): 37-4610.1002/cfg.254Crossref PubMed Scopus (71) Google Scholar, 48Dang V.D. Bohn C. Bolotin-Fukuhara M. Daignan-Fornier B. The CCAAT box-binding factor stimulates ammonium assimilation in Saccharomyces cerevisiae, defining a new cross-pathway regulation between nitrogen and carbon metabolisms.J. Bacteriol. 1996; 178 (8606156): 1842-184910.1128/JB.178.7.1842-1849.1996Crossref PubMed Google Scholar). We thus assessed the activity of the HAP complex with a widely used reporter gene, pCYC1-lacZ (49Guarente L. Ptashne M. Fusion of Escherichia coli lacZ to the cytochrome c gene of Saccharomyces cerevisiae.Proc. Natl. Acad. Sci. U.S.A. 1981; 78 (6264467): 2199-220310.1073/pnas.78.4.2199Crossref PubMed Scopus (338) Google Scholar). Fig. 4A shows that under low cellular labile heme condition (Δhem1-ALA5-), the activity of the HAP complex is highly decreased, and this activity increases proportionally with the amount of cellular labile heme, being slightly higher than in the WT for the Δhem1-ALA100- condition. The master regulator of the activity of the HAP multicomplex is the subunit Hap4p (11Forsburg S.L. Guarente L. Identification and characterization of HAP4: a third component of the CCAAT-bound HAP2/HAP3 heteromer.Genes Dev. 1989; 3 (2676721): 1166-117810.1101/gad.3.8.1166Crossref PubMed Scopus (305) Google Scholar). Cellular amounts of Hap4p were thus assessed under our experimental conditions. Fig. 4B shows that the amount of Hap4p is highly increased proportionally with the a" @default.
• W3008825692 created "2020-03-06" @default.
• W3008825692 creator A5018238719 @default.
• W3008825692 creator A5018984920 @default.
• W3008825692 creator A5021349434 @default.
• W3008825692 creator A5037180539 @default.
• W3008825692 creator A5040907791 @default.
• W3008825692 creator A5045697513 @default.
• W3008825692 creator A5053583878 @default.
• W3008825692 creator A5079466153 @default.
• W3008825692 date "2020-04-01" @default.
• W3008825692 modified "2023-10-10" @default.
• W3008825692 title "“Labile” heme critically regulates mitochondrial biogenesis through the transcriptional co-activator Hap4p in Saccharomyces cerevisiae" @default.
• W3008825692 cites W1567345519 @default.
• W3008825692 cites W1615913434 @default.
• W3008825692 cites W1669883116 @default.
• W3008825692 cites W1923133867 @default.
• W3008825692 cites W1966072209 @default.
• W3008825692 cites W1969392895 @default.
• W3008825692 cites W1970246917 @default.
• W3008825692 cites W1971082641 @default.
• W3008825692 cites W1976039017 @default.
• W3008825692 cites W1982857351 @default.
• W3008825692 cites W1989584376 @default.
• W3008825692 cites W1995267722 @default.
• W3008825692 cites W2006836034 @default.
• W3008825692 cites W2022557762 @default.
• W3008825692 cites W2033062319 @default.
• W3008825692 cites W2037802059 @default.
• W3008825692 cites W2040108963 @default.
• W3008825692 cites W2044856951 @default.
• W3008825692 cites W2046250502 @default.
• W3008825692 cites W2052004838 @default.
• W3008825692 cites W2061895068 @default.
• W3008825692 cites W2062287691 @default.
• W3008825692 cites W2064927443 @default.
• W3008825692 cites W2068371198 @default.
• W3008825692 cites W2069646782 @default.
• W3008825692 cites W2074469961 @default.
• W3008825692 cites W2078258779 @default.
• W3008825692 cites W2082687781 @default.
• W3008825692 cites W2084034472 @default.
• W3008825692 cites W2087062323 @default.
• W3008825692 cites W2088282580 @default.
• W3008825692 cites W2090448900 @default.
• W3008825692 cites W2096601233 @default.
• W3008825692 cites W2098992508 @default.
• W3008825692 cites W2100771810 @default.
• W3008825692 cites W2102284511 @default.
• W3008825692 cites W2102371377 @default.
• W3008825692 cites W2102624197 @default.
• W3008825692 cites W2104099703 @default.
• W3008825692 cites W2112698071 @default.
• W3008825692 cites W2121198137 @default.
• W3008825692 cites W2124961252 @default.
• W3008825692 cites W2136397032 @default.
• W3008825692 cites W2143588920 @default.
• W3008825692 cites W2154768987 @default.
• W3008825692 cites W2156754173 @default.
• W3008825692 cites W2160565330 @default.
• W3008825692 cites W2161260377 @default.
• W3008825692 cites W2183038303 @default.
• W3008825692 cites W2748015212 @default.
• W3008825692 cites W4249123236 @default.
• W3008825692 doi "https://doi.org/10.1074/jbc.ra120.012739" @default.
• W3008825692 hasPubMedCentralId "https://www.ncbi.nlm.nih.gov/pmc/articles/7152774" @default.
• W3008825692 hasPubMedId "https://pubmed.ncbi.nlm.nih.gov/32075909" @default.
• W3008825692 hasPublicationYear "2020" @default.
• W3008825692 type Work @default.
• W3008825692 sameAs 3008825692 @default.
• W3008825692 citedByCount "10" @default.
• W3008825692 countsByYear W30088256922020 @default.
• W3008825692 countsByYear W30088256922021 @default.
• W3008825692 countsByYear W30088256922022 @default.
• W3008825692 countsByYear W30088256922023 @default.
• W3008825692 crossrefType "journal-article" @default.
• W3008825692 hasAuthorship W3008825692A5018238719 @default.
• W3008825692 hasAuthorship W3008825692A5018984920 @default.
• W3008825692 hasAuthorship W3008825692A5021349434 @default.
• W3008825692 hasAuthorship W3008825692A5037180539 @default.
• W3008825692 hasAuthorship W3008825692A5040907791 @default.
• W3008825692 hasAuthorship W3008825692A5045697513 @default.
• W3008825692 hasAuthorship W3008825692A5053583878 @default.
• W3008825692 hasAuthorship W3008825692A5079466153 @default.
• W3008825692 hasBestOaLocation W30088256921 @default.
• W3008825692 hasConcept C104317684 @default.
• W3008825692 hasConcept C131934819 @default.
• W3008825692 hasConcept C181199279 @default.
• W3008825692 hasConcept C185592680 @default.
• W3008825692 hasConcept C2776217839 @default.
• W3008825692 hasConcept C2777229759 @default.
• W3008825692 hasConcept C2777576037 @default.
• W3008825692 hasConcept C28859421 @default.
• W3008825692 hasConcept C55493867 @default.
• W3008825692 hasConcept C86803240 @default.
• W3008825692 hasConcept C88045685 @default.
• W3008825692 hasConcept C95444343 @default.
• W3008825692 hasConceptScore W3008825692C104317684 @default.

• next