Abstract
Chitin is a major MAMP (Microbe-Associated Molecular Pattern) for various fungi and its fragments, chitin oligosaccharides, are known to induce various defense responses in plant cells. Our recent study showed that CEBiP (chitin elicitor binding protein1)) and OsCERK1 (rice CERK1 homologue2)) play an important role as cell surface receptors for chitin elicitor signaling in rice. Since the co-existence of CEBiP and OsCERK1 are necessary in the effective signal transduction of chitin elicitor in rice, we assumed that the formation of receptor complex consisting of CEBiP and OsCERK1 is important for chitin elicitor signal transduction in rice.
Yeast two-hybrid analyses suggested that CEBiP and OsCERK1 have an ability to form the receptor complex(es) as a hetero- or homo-oligomer through the direct interactions of the extracellular domains. In the rice cells expressing the myc-tagged OsCERK1, it was revealed that OsCERK1 was autophosphorylated and the receptor complex(es) containing CEBiP and OsCERK1 existed in the plasma membrane. Further analyses are in progress. 1) Kaku et al., PNAS, 103, 11086 ('06), 2)Miya et al., PNAS, 104, 19613 ('07).
