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Yun JW, Kim SK, Kim H. Prolonged protein turnover of glyceraldehyde-3-phosphate dehydrogenase by phospholipase C-gamma 1 is critical for anchorage-independent growth and ATP synthesis in transformed cells. Cancer Invest 2011; 29:93-101. [PMID: 21210726 DOI: 10.3109/07357907.2010.535062] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
Overexpression of phospholipase C-γl (PLC-γl) in rat 3Y1 fibroblasts leads to the formation of tumors in nude mice. However, the molecular mechanism for PLC-γl-mediated cellular transformation has not been studied in detail. In this study, we found that glyceraldehyde-3-phosphate dehydrogenase (GAPDH), a glycolytic enzyme, protein levels were increased substantially in cells overexpressing PLC-γl, and that PLC-γl upregulation of GAPDH was due to a decrease in ubiquitination, followed by sustained protein turnover and subsequent accumulation. These observations suggest that regulation of the turnover rate of GAPDH is critical for anchorage-independent growth and ATP synthesis of transformed cells.
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Affiliation(s)
- Jae Won Yun
- Department of Life Science, College of Natural Science, Daejin University, Pochen, Kyeonggido, Republic of Korea
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2
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Colell A, Green DR, Ricci JE. Novel roles for GAPDH in cell death and carcinogenesis. Cell Death Differ 2009; 16:1573-81. [PMID: 19779498 DOI: 10.1038/cdd.2009.137] [Citation(s) in RCA: 182] [Impact Index Per Article: 12.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022] Open
Abstract
Growing evidence points to the fact that glucose metabolism has a central role in carcinogenesis. Among the enzymes controlling this energy production pathway, glyceraldehyde-3-phosphate dehydrogenase (GAPDH) is of particular interest. Initially identified as a glycolytic enzyme and considered as a housekeeping gene, this enzyme is actually tightly regulated and is involved in numerous cellular functions. Particularly intriguing are recent reports describing GAPDH as a regulator of cell death. However, its role in cell death is unclear; whereas some studies point toward a proapoptotic function, others describe a protective role and suggest its participation in tumor progression. In this study, we highlight recent findings and discuss potential mechanisms through which cells regulate GAPDH to fulfill its diverse functions to influence cell fate.
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Affiliation(s)
- A Colell
- Department of Cell Death and Proliferation, Institut d'Investigacions Biomèdiques de Barcelona, Consejo Superior de Investigaciones Científicas and Liver Unit, Hospital Clinic i Provincial, Centro de Investigaciones Biomédicas Esther Koplowitz, and CIBEREHD, IDIBAPS, 08036-Barcelona, Spain.
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3
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Chevrollier A, Loiseau D, Chabi B, Renier G, Douay O, Malthièry Y, Stepien G. ANT2 Isoform Required for Cancer Cell Glycolysis. J Bioenerg Biomembr 2005; 37:307-16. [PMID: 16341775 DOI: 10.1007/s10863-005-8642-5] [Citation(s) in RCA: 91] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2005] [Accepted: 09/26/2005] [Indexed: 11/26/2022]
Abstract
The three adenine nucleotide translocator (ANT1 to ANT3) isoforms, differentially expressed in human cells, play a crucial role in cell bioenergetics by catalyzing ADP and ATP exchange across the mitochondrial inner membrane. In contrast to differentiated tissue cells, transformed cells, and their rho(0) derivatives, i.e. cells deprived of mitochondrial DNA, sustain a high rate of glycolysis. We compared the expression pattern of ANT isoforms in several transformed human cell lines at different stages of the cell cycle. The level of ANT2 expression and glycolytic ATP production in these cell lines were in keeping with their metabolic background and their state of differentiation. The sensitivity of the mitochondrial inner membrane potential (Deltapsi) to several inhibitors of glycolysis and oxidative phosphorylation confirmed this relationship. We propose a new model for ATP uptake in cancer cells implicating the ANT2 isoform, in conjunction with hexokinase II and the beta subunit of mitochondrial ATP synthase, in the Deltapsi maintenance and in the aggressiveness of cancer cells.
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4
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Yamada K, Brink I, Bissé E, Epting T, Engelhardt R. Factors influencing [F-18] 2-fluoro-2-deoxy-D-glucose (F-18 FDG) uptake in melanoma cells: the role of proliferation rate, viability, glucose transporter expression and hexokinase activity. J Dermatol 2005; 32:316-34. [PMID: 16043894 DOI: 10.1111/j.1346-8138.2005.tb00903.x] [Citation(s) in RCA: 37] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2004] [Accepted: 01/11/2005] [Indexed: 11/26/2022]
Abstract
Using human (SK-MEL 23, SK-MEL 24 and G361) and murine (B16) melanoma cell lines, the coregulatory potential of the uptake of the positron emission tomography (PET) tracer, [Fluorine-18] 2-fluoro-2-deoxy-D-glucose (F-18 FDG) has been investigated in relationship to tumor characteristics. Comparative studies among the four melanoma cell lines demonstrated that the lowest FDG uptake in SK-MEL 24 corresponded strongly to the data for DT (population doubling time) and MTT (tetrazolium salt) cell viability as well as hexokinase (HK) activity, but was not related to the glucose transporter 1 (GLUT 1) expression level. Furthermore, the FDG uptake in each melanoma cell line measured by cell cycle kinetics was significantly positively correlated to both the proliferation index (PI=S/G2M phase fractions) and the cell viability, though with one exception relating to the PI of the lowest FDG uptake cell line, SK-MEL 24. No positive correlation was found between the expression of GLUT 1 and FDG uptake in any individual cell line. However, the HK activities in SK-MEL 23 and 24 showed considerable positive relationships with FDG uptake. Our present study suggests that both the proliferation rate and the cell viability of melanoma cells may be key factors for FDG uptake and that HK activity, rather than GLUT 1 expression, seems to be a major factor.
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Affiliation(s)
- Kiyoshi Yamada
- Department of Internal Medicine 1, Hematology/Oncology, Freiburg University Medical Center, Hugstetter str. 55, 79106 Freiburg i Br., Germany
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5
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Yoo BC, Ku JL, Hong SH, Shin YK, Park SY, Kim HK, Park JG. Decreased pyruvate kinase M2 activity linked to cisplatin resistance in human gastric carcinoma cell lines. Int J Cancer 2004; 108:532-9. [PMID: 14696117 DOI: 10.1002/ijc.11604] [Citation(s) in RCA: 64] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
Resistance to anticancer drugs is a major obstacle preventing effective treatment of disseminated cancers. Understanding the molecular basis to chemoresistance is likely to provide better treatment. Cell lines resistant to cisplatin or 5-fluorouracil (5-FU) were established from human gastric carcinoma cell lines SNU-638 and SNU-620. Comparative proteomics involving 2-dimensional gel electrophoresis (2-DE) and matrix-associated laser desorption ionization-mass spectroscopy (MALDI-MS) was performed on protein extracts from these parental and drug-resistant derivative lines to screen drug resistance-related proteins. Pyruvate kinase M2 (PK-M2) was identified as a protein showing lower expression in cisplatin-resistant cells compared to parental cells. Consistent with this finding, PK-M2 activity was also lower in cisplatin-resistant cells. Suppression of PK-M2 expression by antisense oligonucleotide resulted in acquired cisplatin resistance in SNU-638 cells. Furthermore, PK-M2 activity in 11 individual human gastric carcinoma cell lines positively correlated with cisplatin sensitivity. Taken together, PK-M2 protein and activity levels were lower in cisplatin-resistant human gastric carcinoma cell lines compared to their parental cell lines. Furthermore, suppression of PK-M2 expression using antisense oligonucleotides increased cisplatin resistance. These data clearly link PK-M2 and cisplatin resistance mechanisms.
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Affiliation(s)
- Byong Chul Yoo
- Research Institute and Hospital, National Cancer Center, Goyang, Gyeonggi, Korea
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6
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Maclean KN, Janosík M, Kraus E, Kozich V, Allen RH, Raab BK, Kraus JP. Cystathionine beta-synthase is coordinately regulated with proliferation through a redox-sensitive mechanism in cultured human cells and Saccharomyces cerevisiae. J Cell Physiol 2002; 192:81-92. [PMID: 12115739 DOI: 10.1002/jcp.10118] [Citation(s) in RCA: 49] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
Cystathionine beta-synthase (CBS) catalyzes the condensation of serine with homocysteine to form cystathionine and occupies a crucial regulatory position between the methionine cycle and the biosynthesis of cysteine by transsulfuration. Analysis of CBS activity under a variety of growth conditions indicated that CBS is coordinately regulated with proliferation in both yeast and human cells. In batch cultures of Saccharomyces cerevisiae, maximal CBS activities were observed in the exponential phase of cells grown on glucose, while growth-arrested cultures or those growing non-fermentatively on ethanol or glycerol had approximately 3-fold less activity. CBS activity assays and Western blotting indicated that growth-specific regulation of CBS is evolutionarily conserved in a range of human cell lines. CBS activity was found to be maximal during proliferation and was reduced two- to five-fold when cells became quiescent at confluence. In cultured HepG2 cells, the human CBS gene is induced by serum and basic fibroblast growth factor and is downregulated, but not abolished, by contact inhibition, serum-starvation, nutrient depletion, or the induction of differentiation. Consequently, for certain cell types, CBS may represent a novel marker of both differentiation and proliferation. The intracellular level of the CBS regulator compound, S-adenosylmethionine, was found to reflect the proliferation status of both yeast and human cells, and as such, constitutes an additional mechanism for proliferation-specific regulation of human CBS. Our data indicates that screening compounds for the ability to affect transsulfuration in cultured cell models must take proliferation status into account to avoid masking regulatory interactions that may be of significance in vivo.
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Affiliation(s)
- Kenneth N Maclean
- Department of Pediatrics, University of Colorado School of Medicine, Denver, Colorado 80262, USA
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7
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Brand K, Netzker R, Aulwurm U, Hermfisse U, Fabian D, Weigert C, Schaefer D, Hamm-Kuenzelmann B. Control of thymocyte proliferation via redox-regulated expression of glycolytic genes. Redox Rep 2001; 5:52-4. [PMID: 10905547 DOI: 10.1179/rer.2000.5.1.52] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/31/2022] Open
Affiliation(s)
- K Brand
- Institute of Biochemistry, University of Erlangen-Nuremberg, Erlangen, Germany.
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8
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Ngai SM, Way MM, Chan H, Tsui SK, Lee CY, Fung KP. In silico studies of energy metabolism of normal and diseased heart. Mol Biol Rep 2000; 27:123-8. [PMID: 11092559 DOI: 10.1023/a:1007121822920] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
Biotechnology research is developing into genomic analyses that involve the simultaneous monitoring of thousands of genes. The development of various bioinformatics resources that provide efficient access to information is necessary. We have used single-pass sequencing of randomly selected cDNA clones to generate expressed sequence tags (ESTs). These ESTs data has been widely used to study gene expression in a variety of heart libraries [1, 21]. Data annotation on our recent finding allows us to construct the profiles of genes in the energy metabolizing pathways (glycolysis and glycogen metabolism) that are expressed in heart cDNA libraries. In silico studies of genes of energy metabolism yields data that are consistent with results derived from conventional metabolic experiments. The change in gene profiles describing the metabolism of diseased hearts is also presented here.
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Affiliation(s)
- S M Ngai
- Department of Biochemistry, The Chinese University of Hong Kong, Shatin, N.T., Special Administrative Region
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9
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Zwerschke W, Jansen-Dürr P. Cell transformation by the E7 oncoprotein of human papillomavirus type 16: interactions with nuclear and cytoplasmic target proteins. Adv Cancer Res 1999; 78:1-29. [PMID: 10547667 DOI: 10.1016/s0065-230x(08)61022-2] [Citation(s) in RCA: 64] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
The E7 oncoprotein of human papillomavirus type 16 (HPV-16) has long been known as a potent immortalizing and transforming agent. However, the molecular mechanisms underlying cell transformation and immortalization by E7 remain largely unknown. It is believed that E7 exerts its oncogenic function at least in part by modulating cellular growth regulatory pathways. Increasing experimental evidence suggests that cell transformation by E7 is mediated by the physical association of E7 with cellular regulatory proteins, whose functions are specifically altered by E7, as exemplified by the well-known interaction of E7 with the retinoblastoma protein. In this review, we summarize the available data on the interaction of E7 with cellular regulatory factors and functional consequences of these interactions. We will focus the review on a set of recently identified new target proteins for the E7 oncoprotein, which sheds new light on E7 functions required for cell transformation and immortalization. Similar to the case of the E6 protein of HPV-16, whose interaction with p53 was long considered its major activity, it now appears that the interaction of E7 with the retinoblastoma protein represents just one of many distinct interactions that are relevant for cell transformation.
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Affiliation(s)
- W Zwerschke
- Deutsches Krebsforschungszentrum, Forschungsschwerpunkt Angewandte Tumorvirologie, Heidelberg, Germany
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10
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Abstract
Previous studies have shown that rapid cell proliferation is associated with elevated glucose consumption. However, those studies did not establish whether glucose is required for prostate cancer cell proliferation or define the molecular mechanisms by which glucose regulates cell division. We addressed these issues by studying two metastatic human prostate cancer cell lines: DU145, which is androgen independent and highly proliferative; and LNCaP, which is androgen dependent and relatively slow growing. We found that proliferation of DU145 cells was significantly inhibited by reduction of glucose in the medium to 0.5 g/L, which is half the physiologic concentration, whereas LNCaP cells grew at control rates even in the presence of only 0.05 g/L glucose. Glucose deprivation of DU145 cells caused a 90% reduction in DNA synthesis; a 10-20-fold reduction in cyclins D and E and CDK4 levels; and cell cycle arrest in G0-G1. However, glucose deprivation did not cause global inhibition of protein synthesis, since mutant p53 levels increased in glucose-deprived DU145 cells. This observed increase in mutant p53 levels was not associated with a rise in p21 levels. Glucose deprivation of DU145 cells also led to apparent dephosphorylation of mutant retinoblastoma (RB) protein. We conclude that: 1) high levels of glucose consumption are required for rapid proliferation of androgen-independent prostate cancer cells, 2) glucose may not be required for slow growth of androgen-dependent prostate cancer cells, and 3) glucose promotes passage of cells through early G1 by increasing the expression of several key cell cycle regulatory proteins that normally inhibit RB function.
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Affiliation(s)
- G Singh
- Houston Veterans Affairs Medical Center, Department of Medicine, Baylor College of Medicine, Texas 77030, USA
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11
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Sirover MA. New insights into an old protein: the functional diversity of mammalian glyceraldehyde-3-phosphate dehydrogenase. BIOCHIMICA ET BIOPHYSICA ACTA 1999; 1432:159-84. [PMID: 10407139 DOI: 10.1016/s0167-4838(99)00119-3] [Citation(s) in RCA: 598] [Impact Index Per Article: 23.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
Glyceraldehyde-3-phosphate dehydrogenase (GAPDH) was considered a classical glycolytic protein examined for its pivotal role in energy production. It was also used as a model protein for analysis of protein structure and enzyme mechanisms. The GAPDH gene was utilized as a prototype for studies of genetic organization, expression and regulation. However, recent evidence demonstrates that mammalian GAPDH displays a number of diverse activities unrelated to its glycolytic function. These include its role in membrane fusion, microtubule bundling, phosphotransferase activity, nuclear RNA export, DNA replication and DNA repair. These new activities may be related to the subcellular localization and oligomeric structure of GAPDH in vivo. Furthermore, other investigations suggest that GAPDH is involved in apoptosis, age-related neurodegenerative disease, prostate cancer and viral pathogenesis. Intriguingly, GAPDH is also a unique target of nitric oxide. This review discusses the functional diversity of GAPDH in relation to its protein structure. The mechanisms through which mammalian cells may utilize GAPDH amino acid sequences to provide these new functions and to determine its intracellular localization are considered. The interrelationship between new GAPDH activities and its role in cell pathologies is addressed.
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Affiliation(s)
- M A Sirover
- Department of Pharmacology, Temple University School of Medicine, Philadelphia PA 19140, USA.
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12
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Netzker R, Fabian D, Weigert C, Brand KA. Functional studies by site-directed mutagenesis on the role of Sp1 in the expression of the pyruvate kinase M and aldolase A genes. BIOCHIMICA ET BIOPHYSICA ACTA 1999; 1444:231-40. [PMID: 10023068 DOI: 10.1016/s0167-4781(98)00281-4] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
During the cell cycle of mitogen stimulated rat thymocytes, an 8-10-fold induction of glycolytic enzymes and a corresponding increase in the mRNA levels has been observed. This prompted us to study the transcriptional regulation of the rat aldolase A and pyruvate kinase M genes. cis-Regulatory elements of both promoters were evaluated by site-directed mutagenesis of promoter/luciferase constructs and transient transfections of rat hepatoma FTO2B cells. Furthermore, the binding proteins were identified by mobility shift assays in the presence of specific antibodies. In the aldolase AH1 promoter, five binding sites for Sp1 and Sp3 and a TPA responsive element were identified as essential for transcriptional regulation. Most of the promoter activity can be attributed to these regulatory elements. In the pyruvate kinase M promoter three out of five binding sites of Sp1 and Sp3 (B box and GC boxes 1 and 3) turned out to be functional in the transfection assays whereas the disruption of GC box 2 had no effect, and the disruption of the GC box 4 had only a minor effect on the promoter activity. Both promoters are stimulated by Sp1 as well as Sp3, as judged by cotransfection experiments of Drosophila SL2 cells. Therefore, the Sp1- and Sp3-directed transcription provides a means for common regulatory mechanism of the aldolase A and the pyruvate kinase M genes.
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Affiliation(s)
- R Netzker
- Institute of Biochemistry, University of Erlangen-Nuremberg, Fahrstr. 17, D-91054, Erlangen, Germany
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13
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Zwerschke W, Mazurek S, Massimi P, Banks L, Eigenbrodt E, Jansen-Dürr P. Modulation of type M2 pyruvate kinase activity by the human papillomavirus type 16 E7 oncoprotein. Proc Natl Acad Sci U S A 1999; 96:1291-6. [PMID: 9990017 PMCID: PMC15456 DOI: 10.1073/pnas.96.4.1291] [Citation(s) in RCA: 200] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
Abstract
We report here that the E7 oncoprotein encoded by the oncogenic human papillomavirus (HPV) type 16 binds to the glycolytic enzyme type M2 pyruvate kinase (M2-PK). M2-PK occurs in a tetrameric form with a high affinity to its substrate phosphoenolpyruvate and a dimeric form with a low affinity to phosphoenolpyruvate, and the transition between both conformations regulates the glycolytic flux in tumor cells. The glycolytic intermediate fructose 1, 6-bisphosphate induces the reassociation of the dimeric to the tetrameric form of M2-PK. The expression of E7 in an experimental cell line shifts the equilibrium to the dimeric state despite a significant increase in the fructose 1,6-bisphosphate levels. Investigations of HPV-16 E7 mutants and the nononcogenic HPV-11 subtype suggest that the interaction of HPV-16 E7 with M2-PK may be linked to the transforming potential of the viral oncoprotein.
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Affiliation(s)
- W Zwerschke
- Deutsches Krebsforschungszentrum, Forschungsschwerpunkt Angewandte Tumorvirologie, Abt. F0301, INF 242, D-69120 Heidelberg, Germany
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14
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Brand K. Aerobic glycolysis by proliferating cells: protection against oxidative stress at the expense of energy yield. J Bioenerg Biomembr 1997; 29:355-64. [PMID: 9387096 DOI: 10.1023/a:1022498714522] [Citation(s) in RCA: 115] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
Primary cultures of mitogen-activated rat thymocytes were used to study energy metabolism, gene expression of glycolytic enzymes, and production of reactive oxygen species during cell cycle progression. During transition from the resting to the proliferating state a 7- to 10-fold increase of glycolytic enzyme induction occurs which enables the cells to meet the enhanced energy demand by increased aerobic glycolysis. Cellular redox changes have been found to regulate gene expression of glycolytic enzymes by reversible oxidative inactivation of Sp1-binding to the cognate DNA-binding sites in the promoter region. In contrast to nonproliferating cells, production of phorbol 12-myristate 13-acetate (PMA)-primed reactive oxygen species (ROS) in proliferating rat thymocytes and HL-60 cells is nearly abolished. Pyruvate, a product of aerobic glycolysis, is an effective scavenger of ROS, which could be shown to be generated mainly at the site of complex III of the mitochondrial respiratory chain. Aerobic glycolysis by proliferating cells is discussed as a means to minimize oxidative stress during the phases of the cell cycle when maximally enhanced biosynthesis and cell division do occur.
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Affiliation(s)
- K Brand
- Institute of Biochemistry, Medical Faculty, University of Erlangen-Nuremberg, Germany
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15
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Netzker R, Weigert C, Brand K. Role of the stimulatory proteins Sp1 and Sp3 in the regulation of transcription of the rat pyruvate kinase M gene. EUROPEAN JOURNAL OF BIOCHEMISTRY 1997; 245:174-81. [PMID: 9128739 DOI: 10.1111/j.1432-1033.1997.00174.x] [Citation(s) in RCA: 36] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
Site-directed mutagenesis of cis-regulatory elements in the 5' flanking region of the rat pyruvate kinase M gene revealed that two out of the three GC boxes (-133/-124 and -48/-39) are involved in the stimulation of a core promoter (-35/+46). These two regions were also protected in DNaseI footprinting assays. Sp1 and Sp3 were identified as binding proteins to all three GC boxes by supershift experiments. Cotransfections in Drosophila SL2 cells revealed a strong stimulatory function of Sp1 and a synergistic effect of Sp3 to Sp1 in the activation of the pyruvate kinase M promoter. No inhibitory effect of Sp3 was detected. These data indicate that binding of Sp1 at two GC boxes is required for full promoter activity of the pyruvate kinase M gene and thus contributes to the observed cell-cycle-dependent expression of this enzyme in proliferating rat thymocytes.
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Affiliation(s)
- R Netzker
- Institute of Biochemistry, Medical Faculty, University of Erlangen-Nuremberg, Germany
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16
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Masten SA, Shiverick KT. Evidence that a mitogen-inducible prolactin-immunoreactive protein in rat spleen lymphocytes is aldolase A. Life Sci 1997; 60:2173-82. [PMID: 9188760 DOI: 10.1016/s0024-3205(97)00232-4] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
This study characterizes several proteins in rat spleen lymphocyte lysates and conditioned medium that are recognized by antiserum to purified rat pituitary prolactin (PRL). One of these proteins, rat prolactin-immunoreactive protein (rPIP-43), has a relative molecular mass (Mr) of 43,000 and is strongly induced by mitogenic stimulation in spleen lymphocytes. A constitutively expressed protein of this size also was detected in the IM-9 human B lymphoblastoid cell line and the Nb2 rat T lymphoma cell line. The N-terminal amino acid sequence of rPIP-43 in spleen lymphocyte lysate was analysed and found to be identical with 25 residues at the N-terminus of the glycolytic enzyme aldolase A. In further experiments, the rPRL antiserum was evaluated for cross-reactivity with an aldolase A preparation and recognized a Mr 43,000 protein in rabbit muscle. Preabsorption of rPRL antiserum with rPRL was found to greatly decrease the intensity of staining of rPRL, aldolase A and rPIP-43. Preabsorption of antiserum with aldolase A had a similar, but less pronounced effect, with the aldolase A band and rPIP-43 being stained less intensely, while there was no effect on the intensity of staining of purified rPRL. Thus, data indicate that rPIP-43 is not a structural variant of PRL, but appears to be a different protein. These results have implications for the use of PRL antiserum to detect PRL in biological samples insofar as aldolase A is a ubiquitously expressed protein.
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Affiliation(s)
- S A Masten
- Department of Pharmacology and Therapeutics, University of Florida, Gainesville 32610-0267, USA
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17
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Schäfer D, Hamm-Künzelmann B, Hermfisse U, Brand K. Differences in DNA-binding efficiency of Sp1 to aldolase and pyruvate kinase promoter correlate with altered redox states in resting and proliferating rat thymocytes. FEBS Lett 1996; 391:35-8. [PMID: 8706925 DOI: 10.1016/0014-5793(96)00701-6] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Abstract
Thymocytes induce their glycolytic enzymes as they undergo transition from the resting to the proliferating state. Corresponding increases in mRNA levels point to a transcriptional regulation. Electrophoretic mobility shift assays revealed that the DNA-binding efficiency of Sp1 is increased when nuclear extracts from proliferating compared to resting rat thymocytes were used. Here we demonstrate that hydrogen peroxide, added to nuclear extract from proliferating cells, decreases the Sp1 DNA-binding activity, whereas in nuclear extracts from resting cells dithioerythritol fully restores DNA-binding efficiency. Moreover we show that in contrast to resting thymocytes, production of reactive peroxide anions upon priming with phorbol 12-myristate 13-acetate is nearly abolished in the proliferating cells. From these results we propose that reactive oxygen intermediates affect the interaction of the Sp1 transcription factor with its consensus sequence and subsequently regulate glycolytic gene expression.
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Affiliation(s)
- D Schäfer
- Institut für Biochemie, Medizinische Fakultät, Universität Erlangen-Nürnberg, Germany
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18
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Oka T, Moriguchi S, Oonishi K, Chikamori-Aoyama M, Kitazato K, Kishino Y. Alteration of energy substrates utilized by small and large thymocytes in resting and stimulating state. Nutr Res 1996. [DOI: 10.1016/0271-5317(96)00076-0] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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