The mitochondrial pyruvate dehydrogenase complex: nucleotide and deduced amino-acid sequences of a cDNA encoding the Arabidopsis thaliana E1 α-subunit

Gene ◽  
1995 ◽  
Vol 164 (2) ◽  
pp. 251-254 ◽  
Author(s):  
Michael H. Luethy ◽  
Jan A. Miernyk ◽  
Douglas D. Randall
Keyword(s):  
Arabidopsis Thaliana ◽  
Amino Acid ◽  
Pyruvate Dehydrogenase ◽  
Pyruvate Dehydrogenase Complex ◽  
Amino Acid Sequences ◽  
Α Subunit ◽  
Dehydrogenase Complex

scholarly journals Amino acid sequences around the sites of phosphorylation in the pig heart pyruvate dehydrogenase complex

1979 ◽  
Vol 181 (2) ◽  
pp. 419-426 ◽  
Author(s):  
P H Sugden ◽  
A L Kerbey ◽  
P J Randle ◽  
C A Waller ◽  
K B M Reid
Keyword(s):  
Amino Acid ◽  
Pyruvate Dehydrogenase ◽  
Pyruvate Dehydrogenase Complex ◽  
Amino Acid Sequences ◽  
Phosphorylation Sites ◽  
Complete Inactivation ◽  
Total P ◽  
Dehydrogenase Complex

1. When pig heart pyruvate dehydrogenase complex was phosphorylated to completion with [gamma-32P]ATP by its intrinsic kinase, three phosphorylation sites were observed. The amino acid sequences around these sites were: sequence 1, Tyr-Gly-Met-Gly-Thr-Ser(P)-Val-Glu-Arg; and sequence 2, Tyr-His-Gly-His-Ser(P)-Met-Ser-Asp-Pro-Gly-Val-Ser(P)-Tyr-Arg. 2. When phosphorylated to inactivation by repetitive additions of limiting quantities of [gamma-32P]ATP, phosphate was incorporated mainly (more than 90%) into Ser-5 of sequence 2. Phosphorylation of this site thus results in activation of pyruvate dehydrogenase. 3. If Ser-5 is phosphorylated with ATP and the enzyme then incubated with [gamma-32P]ATP, phosphorylation of the remaining sites occurred. Ser-12 of sequence 2 is phosphorylated about twice as rapidly as Ser-6 of sequence 1. 4. Incubation of pyruvate dehydrogenase with excess [gamma-32P]ATP with termination of phosphorylation at about 50% complete inactivation showed that Ser-5 of sequence 2 was phosphorylated most rapidly, but also that Ser-12 of sequence 2 was significantly (15% of total) phosphorylated. Ser-6 sequence 1 contained about 1% total P. 5. These results suggest that addition of limiting amounts of ATP produces primarily phosphorylation of Ser-5 of sequence 2 (inactivating site). This also occurs during incubation with excess ATP before complete inactivation occurs, but a greater occupancy of other sites also occurs during this treatment.

scholarly journals Amino acid sequence around lipoic acid residues in the pyruvate dehydrogenase multienzyme complex of Escherichia coli

1980 ◽  
Vol 187 (3) ◽  
pp. 905-908 ◽  
Author(s):  
G Hale ◽  
R N Perham
Keyword(s):  
Escherichia Coli ◽  
Amino Acid ◽  
Amino Acid Sequence ◽  
Lipoic Acid ◽  
Pyruvate Dehydrogenase ◽  
Pyruvate Dehydrogenase Complex ◽  
Amino Acid Sequences ◽  
Single Amino Acid ◽  
Multienzyme Complex ◽  
Dehydrogenase Complex

Amino-acid sequences around two lipoic acid residues in the lipoate acetyltransferase component of the pyruvate dehydrogenase complex of Escherichia coli were investigated. A single amino acid sequence of 13 residues was found. A repeated amino acid sequence in the lipoate acetyltransferase chain might explain this result.

scholarly journals Regulation of mammalian pyruvate dehydrogenase α subunit gene expression by glucose in HepG2 cells

1998 ◽  
Vol 336 (1) ◽  
pp. 49-56 ◽  
Author(s):  
Jie TAN ◽  
Hsin-Sheng YANG ◽  
Mulchand S. PATEL
Keyword(s):  
Pyruvate Dehydrogenase ◽  
Hepg2 Cells ◽  
Promoter Activity ◽  
Mutational Analysis ◽  
Pyruvate Dehydrogenase Complex ◽  
Complex Activity ◽  
Α Subunit ◽  
Effect Of Glucose ◽  
Cells Cultured ◽  
Dehydrogenase Complex

We report the effect of glucose on the expression of the gene encoding the pyruvate dehydrogenase (E1) α subunit (E1α) in human hepatoma (HepG2) cells. Total pyruvate dehydrogenase complex activity as well as the levels of protein and mRNA of the E1α subunit were significantly increased in HepG2 cells cultured in medium containing 16.7 mM glucose compared with 1.0 mM glucose for a period of 4 weeks. The level of E1α mRNA was elevated approx. 2-fold in HepG2 cells cultured for 24 h in medium containing 16.7 mM glucose compared with 1 mM glucose. This effect was specific to glucose and independent of insulin. Nuclear run-on assays and promoter analysis indicate that the glucose-induced increases in the levels of E1α mRNA in HepG2 cells are due to increased transcription of the human E1α (PDHA1) gene. Mutational analysis of the E1α promoter region has identified two regions, from -78 to -73 bp (CCCCTG) and from -8 to -3 bp (GCGGTG), that are responsible for the effect of glucose on promoter activity; the former exhibits a larger effect. These two sequences represent new variations of the carbohydrate-response element that has been identified in other genes. The stimulation of E1α promoter activity by glucose was abolished by okadaic acid at 100 nM but not at 5 nM, suggesting that glucose-mediated regulation of pyruvate dehydrogenase complex E1α gene transcription involves a phosphorylation/dephosphorylation mechanism, possibly involving protein phosphatase-1.

scholarly journals Tissue-specific pyruvate dehydrogenase complex deficiency causes cardiac hypertrophy and sudden death of weaned male mice

2008 ◽  
Vol 295 (3) ◽  
pp. H946-H952 ◽  
Author(s):  
Sukhdeep Sidhu ◽  
Ashish Gangasani ◽  
Lioubov G. Korotchkina ◽  
Gen Suzuki ◽  
James A. Fallavollita ◽  
...  
Keyword(s):  
Skeletal Muscle ◽  
Mouse Model ◽  
Pyruvate Dehydrogenase ◽  
Pyruvate Dehydrogenase Complex ◽  
Left Ventricular ◽  
Oxidative Decarboxylation ◽  
Male Mice ◽  
Wild Type ◽  
Α Subunit ◽  
Dehydrogenase Complex

Pyruvate dehydrogenase complex (PDC) plays an important role in energy homeostasis in the heart by catalyzing the oxidative decarboxylation of pyruvate derived primarily from glucose and lactate. Because various pathophysiological states can markedly alter cardiac glucose metabolism and PDC has been shown to be altered in response to chronic ischemia, cardiac physiology of a mouse model with knockout of the α-subunit of the pyruvate dehydrogenase component of PDC in heart/skeletal muscle (H/SM-PDCKO) was investigated. H/SM-PDCKO mice did not show embryonic lethality and grew normally during the preweaning period. Heart and skeletal muscle of homozygous male mice had very low PDC activity (∼5% of wild-type), and PDC activity in these tissues from heterozygous females was ∼50%. Male mice did not survive for >7 days after weaning on a rodent chow diet. However, they survived on a high-fat diet and developed left ventricular hypertrophy and reduced left ventricular systolic function compared with wild-type male mice. The changes in the heterozygote female mice were of lesser severity. The deficiency of PDC in H/SM-PDCKO male mice greatly compromises the ability of the heart to oxidize glucose for the generation of energy (and hence cardiac function) and results in cardiac pathological changes. This mouse model demonstrates the importance of glucose oxidation in cardiac energetics and function under basal conditions.

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