Biology Reference
In-Depth Information
Chapter 9
Protein Phosphorylation
and Dephosphorylation in Plant Immune
Signaling Systems
Abstract
Protein phosphorylation plays a central role in the plant immune
response signaling. PAMP signals induce rapid and transient phosphorylation of
several proteins/enzymes involved in defense signaling system. The proteins that
make up the signal transduction pathway are present in the cell prior to the per-
ception of PAMP elicitor signal. On perception of the signal these proteins are
activated by post-translational modifi cations and conformational changes induced
by phosphorylation. Protein phosphorylation is carried out by different protein
kinases. PAMP signals are perceived by plant pattern recognition receptors (PRRs),
which belong to the family of receptor-like kinases (RLKs). The PAMPs have been
shown to activate the RLKs by autophosphorylation by their own serine/threonine
kinase. The autophosphorylation of the receptor kinases takes place within few
seconds to few minutes after PAMP treatment and the autophosphorylated RLKs
have been shown to be essential for PAMP signaling in plants. Calcium-dependent
protein kinases (CDPKs) and mitogen-activated protein kinases (MAPKs) regulate
expression of various enzymes involved in ROS, salicylate, jasmonate, ethylene,
and abscisic acid signaling systems by inducing protein/enzyme phosphorylation.
Protein kinase C is involved in phosphorylation of some transcription factors. His
kinase family protein kinase takes part in ethylene signaling system. Protein
dephosphorylation may also be involved in defense signaling and the phosphatases
negatively regulate innate immune responses.
Keywords
Receptor-like kinases (RLKs) • Calcium-dependent protein kinases
(CDPKs) • Mitogen-activated protein kinases (MAPKs) • Protein kinase C • His
kinase family protein kinase • Autophosphorylation • Phosphatases
Search WWH ::
Custom Search