Histidine and tyrosine phosphorylation in pea mitochondria: evidence for protein phosphorylation in respiratory redox signalling.
A 37 kDa protein in pea mitochondria was found to contain phosphorylated residues. Phosphorylation was acid-labile but stable in alkali solution, a unique property of phosphorylation on histidine, indicating that a signal transduction pathway with homology to bacterial two-component systems might exist in plant mitochondria. We also describe the first example of tyrosine phosphorylation in plant organelles and the first indication of protein phosphorylation as part of a redox signalling mechanism in mitochondria. Labelling of three proteins (28, 27 and 12 kDa) was found to be dependent on the redox state of the reaction medium. Their phospho-groups were resistant to alkali as well as acid treatment and labelling was inhibited by the tyrosine kinase inhibitor genistein.
Håkansson
G
G
Lund University, Sweden.
Allen
J F
JF
D006639:Histidine / Q000378:metabolism*; D008928:Mitochondria / Q000378:metabolism; D010084:Oxidation-Reduction; D018532:Pisum sativum / Q000378:metabolism*; D010766:Phosphorylation; D014443:Tyrosine / Q000378:metabolism*
D014443:Tyrosine; D006639:Histidine