Interaction of the Arabidopsis receptor protein kinase Wak1 with a glycine-rich protein, AtGRP-3.
The Arabidopsis wall-associated receptor kinase, Wak1, is a member of the Wak family (Wak1-5) that links the plasma membrane to the extracellular matrix. By the yeast two-hybrid screen, we found that a glycine-rich extracellular protein, AtGRP-3, binds to the extracellular domain of Wak1. Further in vitro binding studies indicated that AtGRP-3 is the only isoform among the six tested AtGRPs that specifically interacts with Waks, and the cysteine-rich carboxyl terminus of AtGRP-3 is essential for its binding to Wak1. We also show that Wak1 and AtGRP-3 form a complex with a molecular size of approximately 500 kDa in vivo in conjunction with the kinase-associated protein phosphatase, KAPP, that has been shown to interact with a number of plant receptor-like kinases. Binding of AtGRP-3 to Wak1 is shown to be crucial for the integrity of the complex. Wak1 and AtGRP-3 are both induced by salicylic acid treatment. Moreover, exogenously added AtGRP-3 up-regulates the expression of Wak1, AtGRP-3, and PR-1 (for pathogenesis-related) in protoplasts. Taken together, our data suggest that AtGRP-3 regulates Wak1 function through binding to the cell wall domain of Wak1 and that the interaction of Wak1 with AtGRP-3 occurs in a pathogenesis-related process in planta.
Park
A R
AR
Kumho Life and Environmental Science Laboratory, Kwangju 500-480, Korea.
Cho
S K
SK
Yun
U J
UJ
Jin
M Y
MY
Lee
S H
SH
Sachetto-Martins
G
G
Park
O K
OK
D017360:Arabidopsis / Q000235:genetics / Q000378:metabolism*; D029681:Arabidopsis Proteins; D001483:Base Sequence; D008565:Membrane Proteins / Q000235:genetics / Q000378:metabolism*; D008969:Molecular Sequence Data; D010940:Plant Proteins / Q000235:genetics / Q000378:metabolism*; D011494:Protein Kinases / Q000235:genetics / Q000378:metabolism*; D016415:Sequence Alignment; D015398:Signal Transduction
D029681:Arabidopsis Proteins; C432244:GRP-3 protein, Arabidopsis; D008565:Membrane Proteins; D010940:Plant Proteins; C071359:GRP protein, Arabidopsis; D011494:Protein Kinases; C101093:WAK1 protein, Arabidopsis