scispace - formally typeset
Search or ask a question
Topic

Pyruvate dehydrogenase kinase

About: Pyruvate dehydrogenase kinase is a research topic. Over the lifetime, 4224 publications have been published within this topic receiving 161052 citations. The topic is also known as: [pyruvate dehydrogenase (lipoamide)] kinase & pyruvate dehydrogenase (lipoamide) kinase.


Papers
More filters
Journal ArticleDOI
TL;DR: Data indicate that the S. minutum pyruvate kinase isoforms, PK1 and PK2, are not interconvertible forms of the same protein, but probably represent chloroplastic and cytosolic isozymes, respectively.

59 citations

Journal ArticleDOI
TL;DR: It is proposed that band F 2 is the α-subunit of the brain pyruvate dehydrogenase complex, which has similar regulatory properties, subcellular location and electrophoretic mobility, and is suggested to have a potential regulatory role in brain function.

59 citations

Journal ArticleDOI
TL;DR: Results suggest that in S. cerevisiae the catabolism of branched-chain amino acids occurs via 2-oxoacid dehydrogenase, not via the 'Ehrlich Pathway'.
Abstract: Saccharomyces cerevisiae possesses 2-oxoacid dehydrogenase (EC 1.2.4.4) similar to that found in mammalian cells. The activity is readily detected in cells which have been cultured in a minimal medium containing a branched-chain amino acid. Mutants defective in lipoamide dehydrogenase also lack 2-oxoacid dehydrogenase and are thus unable to catabolize branched-chain amino acids: 2-oxoacids accumulate in the cultures of these cells. The 2-oxoacid dehydrogenase activity is distinct from both 2-oxoglutarate dehydrogenase and pyruvate dehydrogenase, because it could not be detected in assay conditions which permitted the measurement of 2-oxoglutarate dehydrogenase and vice versa. In addition, a strain lacking 2-oxoglutarate dehydrogenase (kgd1::URA3) retained 2-oxoacid dehydrogenase as did a mutant specifically lacking pyruvate dehydrogenase (pda1::Tn5ble). In complex media the specific activity of this enzyme is highest in YEP (yeast extract-peptone)-glycerol and lowest in YEP-acetate and YEP-fructose. 2-Oxoacid dehydrogenase could not be detected in cells which had been transferred to sporulation medium. These results suggest that in S. cerevisiae the catabolism of branched-chain amino acids occurs via 2-oxoacid dehydrogenase, not via the ‘Ehrlich Pathway’.

59 citations

Journal ArticleDOI
TL;DR: It is suggested that insulin increases the fraction of pyruvate dehydrogenase present in the tissue in the active dephospho form by increasing the activity of pyRuvatehydrogenase phosphate phosphatase.
Abstract: 1. The mechanism by which insulin activates pyruvate dehydrogenase in rat epididymal adipose tissue was further investigated. 2. When crude extracts, prepared from tissue segments previously exposed to insulin (2m-i.u/ml) for 2min, were supplemented with Mg-2+, Ca-2+, glucose and hexokinase and incubated at 30 degrees C, they displayed an enhanced rate of increase in pyruvate dehydrogenase activity compared with control extracts. 3. When similar extracts were instead supplemented with fluoride, ADP, creatine phosphate and creatine kinase, the rate of decrease in pyruvate dehydrogenase activity observed during incubation at 30 degrees C was unaffected by insulin treatment. 4. It is suggested that insulin increases the fraction of pyruvate dehydrogenase present in the tissue in the active dephospho form by increasing the activity of pyruvate dehydrogenase phosphate phosphatase.

59 citations

Journal ArticleDOI
TL;DR: Pyruvate carboxylation through malic enzyme is active during energy deficiency and leads to an increase in the level of dicarboxylates that can be metabolized through the tricar boxylic acid cycle for ATP production, and may be one mechanism through which treatment is effective.
Abstract: Carboxylation of pyruvate in the brain was for many years thought to occur only in glia, an assumption that formed much of the basis for the concept of the glutamine cycle. It was shown recently, however, that carboxylation of pyruvate to malate occurs in neurons and that it supports formation of transmitter glutamate. The role of pyruvate carboxylation in neurons is to ensure tricarboxylic acid cycle activity by compensating for losses of alpha-ketoglutarate that occur through release of transmitter glutamate and GABA; these amino acids are alpha-ketoglutarate derivatives. Available data suggest that neuronal pyruvate carboxylation is quantitatively important. But because there is no net CO(2) fixation in the brain, pyruvate carboxylation must be balanced by decarboxylation of malate or oxaloacetate. Such decarboxylation occurs in both neurons and astrocytes. Several in vitro studies have shown a neuroprotective effect of pyruvate supplementation. Pyruvate carboxylation may be one mechanism through which such treatment is effective, because pyruvate carboxylation through malic enzyme is active during energy deficiency and leads to an increase in the level of dicarboxylates that can be metabolized through the tricarboxylic acid cycle for ATP production.

59 citations


Network Information
Related Topics (5)
Mitochondrion
51.5K papers, 3M citations
87% related
Protein kinase A
68.4K papers, 3.9M citations
86% related
Phosphorylation
69.3K papers, 3.8M citations
85% related
Endoplasmic reticulum
48.3K papers, 2.4M citations
84% related
Intracellular
41.4K papers, 1.8M citations
84% related
Performance
Metrics
No. of papers in the topic in previous years
YearPapers
202329
202234
202161
202063
201959
201851