scholarly journals Regulation of mammalian pyruvate dehydrogenase complex by phosphorylation: complexity of multiple phosphorylation sites and kinases

2001 ◽  
Vol 33 (4) ◽  
pp. 191-197 ◽  
Author(s):  
Mulchand S Patel ◽  
Lioubov G Korotchkina
Keyword(s):  
Pyruvate Dehydrogenase ◽  
Pyruvate Dehydrogenase Complex ◽  
Phosphorylation Sites ◽  
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.

The Pyruvate Dehydrogenase Complex as a Target for Gene Therapy

2003 ◽  
Vol 3 (3) ◽  
pp. 239-245 ◽  
Author(s):  
Peter Stacpoole ◽  
Renius Owen ◽  
Terence Flotte
Keyword(s):  
Gene Therapy ◽  
Pyruvate Dehydrogenase ◽  
Pyruvate Dehydrogenase Complex ◽  
Dehydrogenase Complex

scholarly journals Evidence for existence of tissue-specific regulation of the mammalian pyruvate dehydrogenase complex

1998 ◽  
Vol 329 (1) ◽  
pp. 191-196 ◽  
Author(s):  
Melissa M. BOWKER-KINLEY ◽  
I. Wilhelmina DAVIS ◽  
Pengfei WU ◽  
A. Robert HARRIS ◽  
M. Kirill POPOV
Keyword(s):  
Tissue Distribution ◽  
Pyruvate Dehydrogenase ◽  
Pyruvate Dehydrogenase Complex ◽  
Pyruvate Dehydrogenase Kinase ◽  
Synthetic Analogue ◽  
Complex Activity ◽  
Acetyl Coa ◽  
Tissue Specific ◽  
Specific Regulation ◽  
Dehydrogenase Complex

Tissue distribution and kinetic parameters for the four isoenzymes of pyruvate dehydrogenase kinase (PDK1, PDK2, PDK3 and PDK4) identified thus far in mammals were analysed. It appeared that expression of these isoenzymes occurs in a tissue-specific manner. The mRNA for isoenzyme PDK1 was found almost exclusively in rat heart. The mRNA for PDK3 was most abundantly expressed in rat testis. The message for PDK2 was present in all tissues tested but the level was low in spleen and lung. The mRNA for PDK4 was predominantly expressed in skeletal muscle and heart. The specific activities of the isoenzymes varied 25-fold, from 50 nmol/min per mg for PDK2 to 1250 nmol/min per mg for PDK3. Apparent Ki values of the isoenzymes for the synthetic analogue of pyruvate, dichloroacetate, varied 40-fold, from 0.2 mM for PDK2 to 8 mM for PDK3. The isoenzymes were also different with respect to their ability to respond to NADH and NADH plus acetyl-CoA. NADH alone stimulated the activities of PDK1 and PDK2 by 20 and 30% respectively. NADH plus acetyl-CoA activated these isoenzymes nearly 200 and 300%. Under comparable conditions, isoenzyme PDK3 was almost completely unresponsive to NADH, and NADH plus acetyl-CoA caused inhibition rather than activation. Isoenzyme PDK4 was activated almost 2-fold by NADH, but NADH plus acetyl-CoA did not activate above the level seen with NADH alone. These results provide the first evidence that the unique tissue distribution and kinetic characteristics of the isoenzymes of PDK are among the major factors responsible for tissue-specific regulation of the pyruvate dehydrogenase complex activity.

Sign in / Sign up

Export Citation Format

Share Document