====== The Type III Effector XopJ3 from //Xanthomonas// ======

Author: [[https://www.researchgate.net/profile/Doron_Teper|Doron Teper]]

Class: XopJ\\
Family: XopJ3\\
Prototype: AvrRxv (//Xanthomonas euvesicatoria// pv. //euvesicatoria//, ex //Xanthomonas campestris// pv. //vesicatoria//; strain 75-3)\\
GenBank ID: [[http://www.ncbi.nlm.nih.gov/protein/AAA27595.1|AAA27595.1]] (373 aa)\\
RefSeq ID: [[https://www.ncbi.nlm.nih.gov/protein/WP_011346137.1|WP_011346137.1]] (373 aa)\\
3D structure: Unknown

===== Biological function =====

=== How discovered? ===

AvrRxv/XopJ3 of //X. euvesicatoria// was identified to promote HR in non-host bean plants (Whalen //et al.//, 1988).
=== (Experimental) evidence for being a T3E ===

Tn//5// insertions in multiple hrp genes in //XcvT //75-3 eliminated AvrRxv/XopJ3-mediated HR in tomato line Hawaii 7998 (Ciesiolka //et al.//, 1998). Disruption of the type III secretion system in //Xcv// race T3 abolished secretion of AvrRxv into culture media (Bonshtien //et al.//, 2004).
=== Regulation ===

The //avrRxv //gene is constitutively expressed in the //X. euvesicatoria// tomato-pathogenic strain //XcvT// 92-14 (Ciesiolka //et al.//, 1998). The expression of //avrRxv// was similar in NYB and XVM2 medium and was not dependent on //hrpG //or //hrpX // (Ciesiolka //et al.//, 1998). The //avrRxv// gene has a perfect PIP-box starting downstream of the coding sequence at bp 465 with the sequence TTCGC-N15-TTCGC (Ciesiolka //et al.//, 1998).
=== Phenotypes ===

AvrRxv induce hypersensitive response in tomato line Hawaii 7998 (Whalen //et al.//, 1993; Bonshtien //et al.//, 2004), bean (Whalen //et al.//, 1988) and //Nicotiana benthamiana// (Albers //et al.//, 2019). Inactivation of //arvRxv// (//avrRxv//::Ω) in //XcvT// 75-3 eliminated HR induction and promoted growth in tomato line Hawaii 7998 (Whalen et al., 1993). //Xcv// race T3 (//X. euvesicatoria// pv. //perforans//) introduced with //avrRxv// induced resistance response in tomato line Hawaii 7998 which was characterized by HR, reduced bacterial growth in planta and significant alteration in host transcriptional profile (Bonshtien //et al.//, 2004).
=== Localization ===

AvrRxv is localized predominantly to the cytoplasm and is possibly associated with the plasma and nuclear membranes (Bonshtien //et al.//, 2004).
=== Enzymatic function ===

AvrRxv/XopJ3 belongs to the group of YopJ-family effectors. YopJ-family effectors share a conserved catalytic triad that is identical to that of the C55 family of cysteine proteases (Ma & Ma, 2016). Mutations in the AvrRxv protease catalytic core impaired elicitation of HR and inhibition of bacterial growth in tomato line Hawaii 7998 (Bonshtien //et al.//, 2004).
=== Interaction partners ===

AvrRxv interacts with tomato 14-3-3 protein (Whalen //et al.//, 2008).

===== Conservation =====

=== In xanthomonads ===

YES (//X. euvesicatoria//, //X. hortorum//, //X. nasturtii//, //X. axonopodis//)
=== In other plant pathogens/symbionts ===

YES (//Pseudomonas syringae// spp. (HopZ-family), //Ralstonia solanacearum// (PopP1), //Acidovorax citrulli//, //Bradyrhizobium// sp., //Mesorhizobium// sp., //Sinorhizobium// sp.)

===== References =====

Albers P, Üstün S, Witzel K, Kraner M, Börnke F (2019). A remorin from //Nicotiana benthamiana// interacts with the //Pseudomonas// type-III effector protein HopZ1a and is phosphorylated by the immune-related kinase PBS1. Mol. Plant Microbe Interact. 32: 1229-1242. DOI: [[https://apsjournals.apsnet.org/doi/10.1094/MPMI-04-19-0105-R?url_ver=Z39.88-2003&rfr_id=ori:rid:crossref.org&rfr_dat=cr_pub  0pubmed|10.1094/MPMI-04-19-0105-R]]

Bonshtien A, Lev A, Gibly A, Debbie P, Avni A, Sessa G (2005). Molecular properties of the //Xanthomonas// AvrRxv effector and global transcriptional changes determined by its expression in resistant tomato plants. Mol. Plant Microbe Interact. 18: 300-310. DOI: [[https://doi.org/10.1094/MPMI-18-0300|10.1094/MPMI-18-0300]]

Ciesiolka LD, Hwin T, Gearlds JD, Minsavage GV, Saenz R, Bravo M, Handley V, Conover SM, Zhang H, Caporgno J, Phengrasamy NB, Toms AO, Stall RE, Whalen MC (1999). Regulation of expression of avirulence gene //avrRxv// and identification of a family of host interaction factors by sequence analysis of //avrBsT//. Mol. Plant Microbe Interact. 12: 35-44. DOI: [[https://doi.org/10.1094/MPMI.1999.12.1.35|10.1094/MPMI.1999.12.1.35]]

Ma KW, Ma W (2016). YopJ family effectors promote bacterial infection through a unique acetyltransferase activity. Microbiol. Mol. Biol. Rev. 80: 1011-1027. DOI: [[https://mmbr.asm.org/content/80/4/1011.long|10.1128/MMBR.00032-16]]

Whalen MC, Stall RE, Staskawicz BJ (1988). Characterization of a gene from a tomato pathogen determining hypersensitive resistance in non-host species and genetic analysis of this resistance in bean. Proc. Natl. Acad. Sci. USA 85: 6743-6747. DOI: [[https://doi.org/10.1073/pnas.85.18.6743|10.1073/pnas.85.18.6743]]

Whalen M, Richter T, Zakhareyvich K, Yoshikawa M, Al-Azzeh D, Adefioye A, Spicer G, Mendoza LL, Morales CQ, Klassen V, Perez-Baron G, Toebe CS, Tzovolous A, Gerstman E, Evans E, Thompson C, Lopez M, Ronald PC (2008). Identification of a host 14-3-3 protein that Interacts with //Xanthomonas// effector AvrRxv. Physiol. Mol. Plant Pathol. 72: 46-55. DOI: [[https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3142867/|10.1016/j.pmpp.2008.05.006]]

Whalen MC, Wang JF, Carland FM, Heiskell ME, Dahlbeck D, Minsavage GV, Jones JB, Scott JW, Stall RE, Staskawicz BJ (1993). Avirulence gene //avrRxv// from //Xanthomonas campestris// pv. //vesicatoria// specifies resistance on tomato line Hawaii 7998. Mol. Plant Microbe Interact. 6: 616-627. DOI: [[https://doi.org/10.1094/mpmi-6-616|10.1094/mpmi-6-616]]

===== Acknowledgements =====

This fact sheet is based upon work from COST Action CA16107 EuroXanth, supported by COST (European Cooperation in Science and Technology).