Abstract
Pyruvate dehydrogenase kinase (PDK) specifically phosphorylates the E1alpha subunit of the pyruvate dehydrogenase complex (PDC). Sequence analysis of cloned PDKs led to the proposal that they are mechanistically related to prokaryotic 2-component His-kinases. The reaction mechanism of protein His-kinases involves autophosphorylation of a specific His residue followed by phosphotransfer to an Asp residue. Treatment of recombinant Arabidopsis thaliana PDK with the His-directed reagents diethyl pyrocarbonate (DEPC) and dichloro-(2,2':6', 2"-terpyridine)-platinum(II) dihydrate led to a marked inhibition of autophosphorylation. In addition, DEPC treatment abolished the ability of PDK to trans-phosphorylate and inactivate PDC. These results validate the prediction that PDKs require His residues for activity.
Publication types
-
Research Support, U.S. Gov't, Non-P.H.S.
MeSH terms
-
Arabidopsis / enzymology
-
Arabidopsis / genetics
-
Diethyl Pyrocarbonate / pharmacology
-
Histidine / metabolism*
-
Histidine Kinase
-
Organoplatinum Compounds / pharmacology
-
Phosphorylation
-
Protein Kinase Inhibitors*
-
Protein Kinases / genetics
-
Protein Kinases / metabolism
-
Protein Serine-Threonine Kinases
-
Pyruvate Dehydrogenase (Lipoamide)*
-
Pyruvate Dehydrogenase Acetyl-Transferring Kinase
-
Pyruvate Dehydrogenase Complex / metabolism
-
Recombinant Fusion Proteins / antagonists & inhibitors
-
Recombinant Fusion Proteins / genetics
-
Recombinant Fusion Proteins / metabolism
Substances
-
Organoplatinum Compounds
-
Protein Kinase Inhibitors
-
Pyruvate Dehydrogenase Acetyl-Transferring Kinase
-
Pyruvate Dehydrogenase Complex
-
Recombinant Fusion Proteins
-
Histidine
-
Pyruvate Dehydrogenase (Lipoamide)
-
pyruvate dehydrogenase E1alpha subunit
-
Protein Kinases
-
Protein Serine-Threonine Kinases
-
Histidine Kinase
-
Diethyl Pyrocarbonate