Reference "Rice XA21 Binding Protein 3 Is a Ubiquitin Ligase Required for Full Xa21-Mediated Disease Resistance"

Reference ID

11443

Title

Rice XA21 Binding Protein 3 Is a Ubiquitin Ligase Required for Full Xa21-Mediated Disease Resistance

Source

The Plant cell, 2006, vol. , pp. -

Authors (11)

Wang-Y-S	Pi-L-Y	Chen-X	Chakrabarty-P-K
Jiang-J	Liu-G-Z	Li-L	Benny-U
Oard-J	Ronald-P-C	Song-W-Y

Abstract

XA21 is a receptor-like kinase protein in rice (Oryza sativa) that confers gene-for-
gene resistance to specific races of the causal agent of bacterial blight
disease, Xanthomonas oryzae pv oryzae. We identified XA21 binding protein 3
(XB3), an E3 ubiquitin ligase, as a substrate for the XA21 Ser and Thr kinase.
The interaction between XB3 and the kinase domain of XA21 has been shown in
yeast and in vitro, and the physical association between XB3 and XA21 in vivo
has also been confirmed by coimmunoprecipitation assays. XB3 contains an ankyrin
repeat domain and a RING finger motif that is sufficient for its interaction
with the kinase domain of XA21 and for its E3 ubiquitin ligase activity,
respectively. Transgenic plants with reduced expression of the Xb3 gene are
compromised in resistance to the avirulent race of X. oryzae pv oryzae.
Furthermore, reduced levels of Xb3 lead to decreased levels of the XA21 protein.
These results indicate that Xb3 is necessary for full accumulation of the XA21
protein and for Xa21-mediated resistance.