User Tools

Site Tools




Author: Eran Bosis
Internal reviewer: Jose Gadea
Expert reviewer: Doron Teper

Class: XopAU
Family: XopAU
Prototype: XCV1196 (Xanthomonas euvesicatoria pv. euvesicatoria, ex Xanthomonas campestris pv. vescicatoria; strain 85-10)
GenBank ID: CAJ22827.1 (517 aa)
RefSeq ID: WP_041855031.1 (524 aa)
3D structure: Unknown

Biological function

How discovered?

XopAU was discovered using a machine-learning approach (Teper et al., 2016).

(Experimental) evidence for being a T3E

XopAU fused to the AvrBs2 reporter, was shown to translocate into plant cells in an hrpF-dependent manner (Teper et al., 2016).


XopAU homologs were shown to contain the PIP-box motif in their promoter region (Teper et al., 2018). XopAU from X. citri was found to be regulated by HrpG and HrpX (Guo et al., 2011).


Agrobacterium-mediated expression of XopAU in Nicotiana benthamiana was shown to promote activation of immune responses and cell death that were dependent on the kinase activity of the effector. XopAU was shown to promote chlorosis and accumulation of PR proteins when delivered by Xanthomonas euvesicatoria into pepper leaves. Delivery of XopAU in plant cells by Xanthomonas campestris pv. campestris caused cell death. XopAU was shown to interact in yeast and in planta with MKK2 and to phosphorylate MKK2 in vitro (Teper et al., 2018). Co-expression of XopAU and MKK2 enhanced MKK2 phosphorylation in N. benthamiana leaves. In conclusion, XopAU contributes to X. euvesicatoria disease symptoms in pepper plants and manipulates host MAPK signaling through phosphorylation and activation of MKK2 (Teper et al., 2018).



Enzymatic function

XopAU is an active protein kinase in vitro (Teper et al., 2018).

Interaction partners

XopAU was shown to interact with tomato MAPKK MKK2 and MAP kinases. Co-expression of XopAU and MKK2 in yeast caused a growth-inhibition phenotype. XopAU was shown to phosphorylate MKK2 in vitro and to promote phosphorylation of MKK2 at multiple sites in planta (Teper et al., 2018). XopAU was shown to interact with tomato 14-3-3 (TFT) proteins (Dubrow et al., 2018).


In xanthomonads

Yes (e.g., X. fuscans, X. citri, X. oryzae, X. fragariae).

In other plant pathogens/symbionts

Yes (Acidovorax spp.).


Dubrow Z, Sunitha S, Kim JG, Aakre CD, Girija AM, Sobol G, Teper D, Chen YC, Ozbaki-Yagan N, Vance H, Sessa G, Mudgett MB (2018). Tomato 14-3-3 proteins are required for Xv3 disease resistance and interact with a subset of Xanthomonas euvesicatoria effectors. Mol. Plant Microbe Interact. 31: 1301-1311. DOI: 10.1094/MPMI-02-18-0048-R

Guo Y, Figueiredo F, Jones J, Wang N (2011). HrpG and HrpX play global roles in coordinating different virulence traits of Xanthomonas axonopodis pv. citri. Mol. Plant Microbe Interact. 24: 649-661. DOI: 10.1094/MPMI-09-10-0209

Teper D, Burstein D, Salomon D, Gershovitz M, Pupko T, Sessa G (2016). Identification of novel Xanthomonas euvesicatoria type III effector proteins by a machine‐learning approach. Mol. Plant Pathol. 17: 398-411. DOI: 10.1111/mpp.12288

Teper D, Girija AM, Bosis E, Popov G, Savidor A, Sessa G (2018). The Xanthomonas euvesicatoria type III effector XopAU is an active protein kinase that manipulates plant MAP kinase signaling. PLoS Pathog. 14: e1006880. DOI: 10.1371/journal.ppat.1006880

bacteria/t3e/xopau.txt · Last modified: 2023/05/24 15:41 by rkoebnik