Protein Kinases and Phosphatases Involved in ABA Signaling - Abscisic Acid: Metabolism, Transport and Signaling - page 132

Chapter 8
Protein Kinases and Phosphatases Involved
in ABA Signaling

Shan Liang and Da-Peng Zhang

Abstract Reversible protein phosphorylation, catalyzed by protein kinases and
phosphatases, is involved in almost all key events of cell metabolism and sign-
aling in eukaryotes. A wide array of protein kinases and phosphatases have been
identified as crucial players in ABA signaling, among which Ca 2 + -dependent pro-
tein kinases (CDPKs), sucrose non-fermenting-1 (SNF1)-related protein kinases
(SnRKs), mitogen-activated protein kinases (MAPKs), receptor-like kinases
(RLKs), and type 2C and type 2A protein phosphatases (PP2Cs and PP2As) are
relatively best characterized and their functional mechanisms in ABA signaling
begin to be understood. In this chapter, we examine these advances in the plant
protein kinases and phosphatases as well as the insights of these discoveries into
the mechanisms of ABA-signaling network.

Keywords ABA signal transduction · Phosphorylation · Dephosphorylation ·
Protein kinase · Protein phosphatase

8.1 Introduction

Reversible protein phosphorylation (i.e., protein phosphorylation and de-phospho-
rylation), catalyzed by protein kinases and phosphatases, represents a major form
of reversible posttranslational modification. Molecular genetic and biochemical
studies have greatly advanced our knowledge of protein kinases and phosphatases
and provide compelling evidence that the reversible protein phosphorylation is
involved in almost all key events of cell metabolism and signaling in eukaryotes,
serving as an important “on-and-off” switch in the regulation of the cell activities