PLANT PHYSIOLOGY , Vol 103, Issue 4 1393-1397, Copyright © 1993 by American Society of Plant Biologists
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CELL BIOLOGY AND SIGNAL TRANSDUCTION |
Purification of Potato Leaf Plasma Membrane Protein pp34, a Protein Phosphorylated in Response to Oligogalacturonide Signals for Defense and Development
T. Jacinto, E. E. Farmer and C. A. Ryan
Institute of Biological Chemistry, Washington State University, Pullman, Washington 99164-6340
A potato (Solanum tuberosum L.) plasma membrane protein called pp34, the
only known example of a plasma membrane protein that is phosphorylated
specifically in response to defined Oligogalacturonide signals in plants,
has been purified to apparent homogeneity. Polyclonal antibodies raised in
rabbits against the purified pp34 protein immunoprecipitated a single
thiophosphorylated protein species from potato plasma membranes, as
analyzed by two-dimensional denaturing electrophoresis and fluorography.
The pp34 antibodies also recognized a single protein in tomato
(Lycopersicon esculentum L.) membranes that is thiophosphorylated in
response to Oligogalacturonide elicitors, as demonstrated by western
blotting and specific immunoprecipitation. These experiments confirm the
identity of the tomato membrane protein as a pp34 homolog and establish the
high monospecificity of the pp34 antibodies. This will permit further
investigation of the role of protein phosphorylation in oligouronide
signaling for defensive genes in potato and tomato plants.
