scholarly journals SpecificArabidopsis thalianamalic enzyme isoforms can provide anaplerotic pyruvate carboxylation function inSaccharomyces cerevisiae

FEBS Journal ◽  
2017 ◽  
Vol 284 (4) ◽  
pp. 654-665 ◽  
Author(s):  
Mariana Beatriz Badia ◽  
Robert Mans ◽  
Alicia V. Lis ◽  
Marcos Ariel Tronconi ◽  
Cintia Lucía Arias ◽  
...  
Keyword(s):  
Pyruvate Carboxylation ◽  
Enzyme Isoforms

The Expression of Glutaminases and their Association with Clinicopathological Parameters in the Head and Neck Cancers

2021 ◽  
Vol 22 ◽  
Author(s):  
Haneen A . Basheer ◽  
Lina Elsalem ◽  
Anwar Salem ◽  
Artysha Tailor ◽  
Keith Hunter ◽  
...  
Keyword(s):  
Head And Neck ◽  
Tumor Grade ◽  
Head And Neck Cancers ◽  
Glutamine Metabolism ◽  
Clinicopathological Parameters ◽  
Normal Tissues ◽  
Enzyme Isoforms ◽  
Cd147 Expression ◽  
New Treatment ◽  
First Time

Background: The increased glutamine metabolism is a characteristic feature of cancer cells. The interconversion between glutamine and glutamate is catalyzed by two glutaminase isoforms, GLS1 and GLS2, which appear to have different roles in different types of cancer. We investigated for the first time the protein expression of GLS1 and GLS2, and their correlation with advanced clinicopathological parameters in head and neck cancers. Method: Consecutive slides from a tissue microarray comprised of 80 samples ranging from normal to metastatic, were stained immunohistochemically for GLS1, GLS2, HIF-1α or CD147. Following analysis by two expert pathologists we carried out statistical analysis of the scores. Results: GLS1 and GLS2 are upregulated at protein level in head and neck tumours compared to normal tissues and this increased expression correlated positively (GLS1) and negatively (GLS2) with tumor grade, indicating a shift of expression between GLS enzyme isoforms based on tumor differentiation. Increased expression of GLS1 was associated with high CD147 expression; and elevated GLS2 expression was associated with both high CD147 and high HIF-1α expressions. The correlation of the GLS1 and GLS2 with HIF-1α or CD147 was strongly associated with more advanced clinicopathological parameters. Conclusion: The increased expression of GLS1 and GLS2 may be explored as a new treatment for head and neck cancers.

scholarly journals Regulation of mitochondrial pyruvate carboxylation in isolated hepatocytes by acute insulin treatment

1983 ◽  
Vol 214 (2) ◽  
pp. 451-458 ◽  
Author(s):  
A B Chisholm ◽  
E H Allan ◽  
M A Titheradge
Keyword(s):  
Insulin Treatment ◽  
Second Messengers ◽  
Isolated Hepatocytes ◽  
Carboxylase Activity ◽  
Effector Molecules ◽  
Pyruvate Carboxylation ◽  
Isolated Mitochondria ◽  
Glucose Synthesis ◽  
Important Site ◽  
Stimulation Of

The effect of acute insulin treatment of hepatocytes on pyruvate carboxylation in both isolated mitochondria and cells rendered permeable by filipin was examined. Challenging the cells with insulin alone had no effect on either the basal rate of pyruvate carboxylation or gluconeogenesis, although it did suppress the responses to both glucagon and catecholamines. Insulin treatment was unable to antagonize the enhanced rate of pyruvate carboxylation caused by stimulation of the cells with either angiotensin or vasopressin. Neither insulin nor the gluconeogenic hormones altered the total extractable pyruvate carboxylase activity in the isolated mitochondria, suggesting that the effect of hormones at the level of the isolated intact organelle was mediated via alterations in the intramitochondrial concentrations of effector molecules, notably ATP and the [ATP]/[ADP] ratio and substrate availability. The alterations in pyruvate carboxylation correlate well with glucose synthesis in terms of sensitivity to effector molecules, putative second messengers and time of onset of the response, indicating that alterations in the flux through this enzyme are compatible with it being an important site in the control of gluconeogenesis from C3 precursors.

scholarly journals Influence of N-limitation on Malic Enzyme Isoforms and Lipogenesis of Cunninghamella bainieri 2A1

2014 ◽  
Vol 67 (1) ◽  
Author(s):  
Aidil Abdul Hamid ◽  
Shuwahida Shuib ◽  
Ekhlass M. Taha ◽  
Othman Omar ◽  
Mohd Sahaid Khalil ◽  
...  
Keyword(s):  
Lipid Content ◽  
Lipid Accumulation ◽  
Malic Enzyme ◽  
Lipid Synthesis ◽  
Lower Activity ◽  
Ammonium Tartrate ◽  
Ammonium Ions ◽  
Activity Staining ◽  
N Limitation ◽  
Enzyme Isoforms

The influence of the presence of ammonium ions in growth culture on malic enzyme (ME) isoforms activity and lipogenesis in Cunninghamella bainieri 2A1 was investigated. The fungus was cultivated in a nitrogen-limiting medium for 120 h at 30oC under two conditions. One of the cultures was intermittently fed with ammonium tartrate to maintain the ammonium concentrations above 0.5 g/L. The second culture was performed without any feeding to allow N limitation, thus promoting lipid accumulation. Activity staining of ME isoforms was carried out for both cultures. The culture which was not intermittently fed with ammonium tartrate achieved a maximum lipid content of 35% (g/g biomass) at 48 h. This culture possessed five ME isoforms (A, B, C, D and E) with isoform E showing a parallel correlation to lipid accumulation profile. In contrast, intensity of bands representing isoform D decreased as lipid accumulated. No appreciable differences of all other isoforms were observed. However, the culture which was intermittently fed with ammonium tartrate, accumulated only up to 16% lipid (g/g biomass). All isoforms were present but with a more pronounced activity of isoform D and a lower activity of isoform E was observed. These findings support further evidence that isoform E is the key isoform for lipid synthesis in C. bainieri 2A1.

scholarly journals Two small enzyme isoforms mediate mammalian mitochondrial poly(ADP-ribose) glycohydrolase (PARG) activity

2007 ◽  
Vol 313 (13) ◽  
pp. 2920-2936 ◽  
Author(s):  
Ralph G. Meyer ◽  
Mirella L. Meyer-Ficca ◽  
Clifford J. Whatcott ◽  
Elaine L. Jacobson ◽  
Myron K. Jacobson
Keyword(s):  
Enzyme Isoforms
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