scholarly journals Triosephosphate isomerase deficiency: consequences of an inherited mutation at mRNA, protein and metabolic levels

2005 ◽  
Vol 392 (3) ◽  
pp. 675-683 ◽  
Author(s):  
Judit Oláh ◽  
Ferenc Orosz ◽  
László G. Puskás ◽  
László Hackler ◽  
Margit Horányi ◽  
...  
Keyword(s):  
Steady State ◽  
Triosephosphate Isomerase ◽  
Specific Activity ◽  
Energy State ◽  
Dihydroxyacetone Phosphate ◽  
Peptidase Activity ◽  
Mrna Levels ◽  
Regulatory Enzymes ◽  
Computational Data ◽  
Fructose 1,6 Bisphosphate

Triosephosphate isomerase (TPI) deficiency is a unique glycolytic enzymopathy coupled with neurodegeneration. Two Hungarian compound heterozygote brothers inherited the same TPI mutations (F240L and E145Stop), but only the younger one suffers from neurodegeneration. In the present study, we determined the kinetic parameters of key glycolytic enzymes including the mutant TPI for rational modelling of erythrocyte glycolysis. We found that a low TPI activity in the mutant cells (lower than predicted from the protein level and specific activity of the purified recombinant enzyme) is coupled with an increase in the activities of glycolytic kinases. The modelling rendered it possible to establish the steady-state flux of the glycolysis and metabolite concentrations, which was not possible experimentally due to the inactivation of the mutant TPI and other enzymes during the pre-steady state. Our results showed that the flux was 2.5-fold higher and the concentration of DHAP (dihydroxyacetone phosphate) and fructose 1,6-bisphosphate increased 40- and 5-fold respectively in the erythrocytes of the patient compared with the control. Although the rapid equilibration of triosephosphates is not achieved, the energy state of the cells is not ‘sick’ due to the activation of key regulatory enzymes. In lymphocytes of the two brothers, the TPI activity was also lower (20%) than that of controls; however, the remaining activity was high enough to maintain the rapid equilibration of triosephosphates; consequently, no accumulation of DHAP occurs, as judged by our experimental and computational data. Interestingly, we found significant differences in the mRNA levels of the brothers for TPI and some other, apparently unrelated, proteins. One of them is the prolyl oligopeptidase, the activity decrease of which has been reported in well-characterized neurodegenerative diseases. We found that the peptidase activity of the affected brother was reduced by 30% compared with that of his neurologically intact brother.

Modulation of human DNA methyltransferase activity and mRNA levels in the monoblast cell line U937 induced to differentiate with dibutyryl cyclic AMP and phorbol ester

1993 ◽  
Vol 11 (2) ◽  
pp. 191-200 ◽  
Author(s):  
P Soultanas ◽  
P D Andrews ◽  
D R Burton ◽  
D P Hornby
Keyword(s):  
Steady State ◽  
Cyclic Amp ◽  
Gene Transcription ◽  
Phorbol Ester ◽  
Specific Activity ◽  
Mrna Levels ◽  
Dibutyryl Cyclic Amp ◽  
Nuclear Extracts ◽  
Steady State Levels ◽  
Stimulation Of

ABSTRACT The regulation of DNA (cytosine-5) methyltransferase (DNA MeTase) enzyme activity and gene expression was examined in the monoblastoid U937 cell line induced to differentiate with either dibutyryl cyclic AMP (dbcAMP) or phorbol ester. dbcAMP treatment was found to cause the rapid (<4 h) suppression of DNA MeTase specific activity, with no DNA MeTase activity detectable after 10 h. Equally, no DNA MeTase activity was detectable in nuclear extracts of fresh peripheral blood monocytes. Using both a U937 DNA MeTase cDNA and a mouse DNA MeTase cDNA as probes, steady-state levels of DNA MeTase mRNA were found to decline sharply between 4 and 15 h after dbcAMP treatment. No DNA MeTase mRNA was detectable after 20 h of dbcAMP treatment. Nuclear run-on analysis showed there to be only a small (40%) suppression of DNA MeTase gene transcription in cells treated with dbcAMP for 24 h, implying a role for post-transcriptional processes in the regulation of DNA MeTase mRNA levels. The observed decline in DNA MeTase activity/mRNA levels appeared to precede the dbcAMP-induced arrest in DNA replication, as judged by the incorporation of tritiated thymidine into DNA. In contrast to the effect of dbcAMP, treatment of U937 cells with the phorbol ester 12-O-tetradecanoyl phorbol-13-acetate (TPA) led to an overall stimulation of DNA MeTase specific activity. The TPA response was found to be complex and broadly consisted of an early (0–15 h) burst of DNA MeTase activity followed by a more gradual sustained increase in DNA MeTase activity after prolonged (16–40 h) TPA treatment. The early phase of high DNA MeTase activity was not mirrored by an increase in steady-state levels of DNA MeTase mRNA, as judged by Northern blot analysis. However, a substantial induction of DNA MeTase mRNA levels was observed after 20–24 h of TPA treatment. Nuclear run-on analysis showed this not to be due to any significant increase in DNA MeTase gene transcription. The observed increases in DNA MeTase activity/mRNA levels were observed whilst cells were undergoing deproliferation. Interestingly, the addition of TPA and more physiological protein kinase C (PKC) activators, such as diacylglycerol and phosphatidylserine, to DNA MeTase-enriched nuclear extracts generated a 4·5-fold and a 1·5-fold increase in DNA MeTase specific activity respectively. The TPA-induced stimulation of DNA MeTase activity could be inhibited by the PKC inhibitor H-9, implicating a role for PKC in the regulation of DNA MeTase activity in vivo.

Medical and Veterinary Importance of the Moonlighting Functions of Triosephosphate Isomerase

2019 ◽  
Vol 20 (4) ◽  
pp. 304-315 ◽  
Author(s):  
Mónica Rodríguez-Bolaños ◽  
Ruy Perez-Montfort
Keyword(s):  
Cell Cycle ◽  
Immune Response ◽  
Triosephosphate Isomerase ◽  
Dihydroxyacetone Phosphate ◽  
Canonical Function ◽  
Moonlighting Protein ◽  
Veterinary Importance ◽  
Moonlighting Functions

Triosephosphate isomerase is the fifth enzyme in glycolysis and its canonical function is the reversible isomerization of glyceraldehyde-3-phosphate and dihydroxyacetone phosphate. Within the last decade multiple other functions, that may not necessarily always involve catalysis, have been described. These include variations in the degree of its expression in many types of cancer and participation in the regulation of the cell cycle. Triosephosphate isomerase may function as an auto-antigen and in the evasion of the immune response, as a factor of virulence of some organisms, and also as an important allergen, mainly in a variety of seafoods. It is an important factor to consider in the cryopreservation of semen and seems to play a major role in some aspects of the development of Alzheimer&#039;s disease. It also seems to be responsible for neurodegenerative alterations in a few cases of human triosephosphate isomerase deficiency. Thus, triosephosphate isomerase is an excellent example of a moonlighting protein.

scholarly journals Hormonal regulation of cholesterol 7alpha-hydroxylase specific activity, mRNA levels, and transcriptional activity in vivo in the rat

1997 ◽  
Vol 38 (12) ◽  
pp. 2483-2491 ◽  
Author(s):  
W M Pandak ◽  
D M Heuman ◽  
K Redford ◽  
R T Stravitz ◽  
J Y Chiang ◽  
...  
Keyword(s):  
Hormonal Regulation ◽  
Transcriptional Activity ◽  
Specific Activity ◽  
Mrna Levels

scholarly journals Genomic structure of murine methylmalonyl-CoA mutase: evidence for genetic and epigenetic mechanisms determining enzyme activity

1993 ◽  
Vol 296 (3) ◽  
pp. 663-670 ◽  
Author(s):  
M F Wilkemeyer ◽  
E R Andrews ◽  
F D Ledley
Keyword(s):  
Enzyme Activity ◽  
Steady State ◽  
Transcription Initiation ◽  
Cultured Cells ◽  
Genomic Structure ◽  
Genetic Regulation ◽  
Regulatory Elements ◽  
Transcription Unit ◽  
Mrna Levels ◽  
Sequence Motifs

Methylmalonyl-CoA mutase (MCM) is a nuclear-encoded mitochondrial matrix enzyme. We have reported characterization of murine MCM and cloning of a murine MCM cDNA and now describe the murine Mut locus, its promoter and evidence for tissue-specific variation in MCM mRNA, enzyme and holo-enzyme levels. The Mut locus spans 30 kb and contains 13 exons constituting a unique transcription unit. A B1 repeat element was found in the 3′ untranslated region (exon 13). The transcription initiation site was identified and upstream sequences were shown to direct expression of a reporter gene in cultured cells. The promoter contains sequence motifs characteristic of: (1) TATA-less housekeeping promoters; (2) enhancer elements purportedly involved in co-ordinating expression of nuclear-encoded mitochondrial proteins; and (3) regulatory elements including CCAAT boxes, cyclic AMP-response elements and potential AP-2-binding sites. Northern blots demonstrate a greater than 10-fold variation in steady-state mRNA levels, which correlate with tissue levels of enzyme activity. However, the ratio of holoenzyme to total enzyme varies among different tissues, and there is no correlation between steady-state mRNA levels and holoenzyme activity. These results suggest that, although there may be regulation of MCM activity at the level of mRNA, the significance of genetic regulation is unclear owning to the presence of epigenetic regulation of holoenzyme formation.

Influence of environmental enrichment on steady-state mRNA levels for EAAC1, AMPA1 and NMDA2A receptor subunits in rat hippocampus

2007 ◽  
Vol 1174 ◽  
pp. 18-27 ◽  
Author(s):  
Josefine Andin ◽  
Martin Hallbeck ◽  
Abdul H. Mohammed ◽  
Jan Marcusson
Keyword(s):  
Steady State ◽  
Environmental Enrichment ◽  
Rat Hippocampus ◽  
Mrna Levels

Quantitative assessment of ground squirrel mRNA levels in multiple stages of hibernation

2002 ◽  
Vol 10 (2) ◽  
pp. 93-102 ◽  
Author(s):  
L. Elaine Epperson ◽  
Sandra L. Martin
Keyword(s):  
Steady State ◽  
Core Body Temperature ◽  
Ground Squirrels ◽  
Apolipoprotein A1 ◽  
Mrna Levels ◽  
Cdna Subtraction ◽  
Global Issues ◽  
Α2 Macroglobulin ◽  
Steady State Levels ◽  
Molecular Components

Hibernators in torpor dramatically reduce their metabolic, respiratory, and heart rates and core body temperature. These extreme physiological conditions are frequently and rapidly reversed during the winter hibernation season via endogenous mechanisms. This phenotype must derive from regulated expression of the hibernator’s genome; to identify its molecular components, a cDNA subtraction was used to enrich for seasonally upregulated mRNAs in liver of golden-mantled ground squirrels. The relative steady-state levels for seven mRNAs identified by this screen, plus five others, were measured and analyzed for seasonal and stage-specific differences using kinetic RT-PCR. Four mRNAs show seasonal upregulation in which all five winter stages differ significantly from and are higher than summer (α2-macroglobulin, apolipoprotein A1, cathepsin H, and thyroxine-binding globulin). One of these mRNAs, α2-macroglobulin, varies during the winter stages with significantly lower levels at late torpor. None of the 12 mRNAs increased during torpor. The implications for these newly recognized upregulated mRNAs for hibernation as well as more global issues of maintaining steady-state levels of mRNA during torpor are discussed.

Cyclic AMP analogs and retinoic acid influence the expression of retinoic acid receptor alpha, beta, and gamma mRNAs in F9 teratocarcinoma cells

1990 ◽  
Vol 10 (1) ◽  
pp. 391-396
Author(s):  
L Hu ◽  
L J Gudas
Keyword(s):  
Retinoic Acid ◽  
Steady State ◽  
Cyclic Amp ◽  
Cellular Response ◽  
Retinoic Acid Receptor ◽  
Mrna Level ◽  
Mrna Levels ◽  
Protein Synthesis Inhibitors ◽  
Receptor Alpha ◽  
F9 Teratocarcinoma

Retinoic acid (RA) receptor alpha (RAR alpha) and RAR gamma steady-state mRNA levels remained relatively constant over time after the addition of RA to F9 teratocarcinoma stem cells. In contrast, the steady-state RAR beta mRNA level started to increase within 12 h after the addition of RA and reached a 20-fold-higher level by 48 h. This RA-associated RAR beta mRNA increase was not prevented by protein synthesis inhibitors but was prevented by the addition of cyclic AMP analogs. In the presence of RA, cyclic AMP analogs also greatly reduced the RAR alpha and RAR gamma mRNA levels, even though cyclic AMP analogs alone did not alter these mRNA levels. The addition of either RA or RA plus cyclic AMP analogs did not result in changes in the three RAR mRNA half-lives. These results suggest that agents which elevate the internal cyclic AMP concentration may also affect the cellular response to RA by altering the expression of the RARs.

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