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bacteria:t3e:xopz [2024/12/16 14:32] – [The Type III Effector XopZ from //Xanthomonas//] rkoebnikbacteria:t3e:xopz [2025/07/04 23:49] (current) jfpothier
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 Author: Marlène Lachaux\\ Author: Marlène Lachaux\\
-Internal reviewer: [[https://www.researchgate.net/profile/Joel_Pothier2|Joël F. Pothier]]+Internal reviewer: [[https://www.researchgate.net/profile/Joel_Pothier2|Joël F. Pothier]]\\
  
 Class: XopZ\\ Class: XopZ\\
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 XopZ2 was described in Potnis //et al.//, 2011 as a novel candidate effector gene upstream of //hrpW// in //Xanthomonas vesicatoria// strain 1111 (=ATCC 35937) ([[https://www.ncbi.nlm.nih.gov/protein/EGD08510.1|EGD08510.1]]=XVE_3221) and //Xanthomonas gardneri// strain 101 (=ATCC 19865) ([[https://www.ncbi.nlm.nih.gov/protein/EGD18683.1|EGD18683.1]]=XGA_2762; Potnis //et al.//, 2011). It was also shown to be functional i.e. as being translocated using a reporter gene assay (AvrBs2-based assay; Potnis //et al.//, 2011). The pairwise sequence identity below 50% warrants assigning these two proteins to a new family within the XopZ class, named XopZ2 (Potnis //et al.//, 2011). XopZ2 was described in Potnis //et al.//, 2011 as a novel candidate effector gene upstream of //hrpW// in //Xanthomonas vesicatoria// strain 1111 (=ATCC 35937) ([[https://www.ncbi.nlm.nih.gov/protein/EGD08510.1|EGD08510.1]]=XVE_3221) and //Xanthomonas gardneri// strain 101 (=ATCC 19865) ([[https://www.ncbi.nlm.nih.gov/protein/EGD18683.1|EGD18683.1]]=XGA_2762; Potnis //et al.//, 2011). It was also shown to be functional i.e. as being translocated using a reporter gene assay (AvrBs2-based assay; Potnis //et al.//, 2011). The pairwise sequence identity below 50% warrants assigning these two proteins to a new family within the XopZ class, named XopZ2 (Potnis //et al.//, 2011).
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 === (Experimental) evidence for being a T3E === === (Experimental) evidence for being a T3E ===
  
 The secretion of XopZ //in planta// was shown using a //B. pertussis// Cya translocation reporter assay (Furutani //et al.//, 2009). With a PIP box 58 bp upstream of the predicted translation start site, //xopZ// <sub>PXO99</sub> gene is certainly inducible //in planta// and regulated through the hypersensitive reaction and pathogenicity (Hrp) regulatory network (Song and Yang, 2010). PXO99<sup>A</sup>  and an //hrpG// mutant were grown in nutrient broth (NB) or //Xanthomonas hrp//-inducing medium (XOM2) (Song and Yang, 2010). The expression of //xopZ// <sub>PXO99</sub> was only observed, by RT-PCR, in XOM2 medium and was //hrpG// dependent (Song and Yang, 2010). The secretion of XopZ //in planta// was shown using a //B. pertussis// Cya translocation reporter assay (Furutani //et al.//, 2009). With a PIP box 58 bp upstream of the predicted translation start site, //xopZ// <sub>PXO99</sub> gene is certainly inducible //in planta// and regulated through the hypersensitive reaction and pathogenicity (Hrp) regulatory network (Song and Yang, 2010). PXO99<sup>A</sup>  and an //hrpG// mutant were grown in nutrient broth (NB) or //Xanthomonas hrp//-inducing medium (XOM2) (Song and Yang, 2010). The expression of //xopZ// <sub>PXO99</sub> was only observed, by RT-PCR, in XOM2 medium and was //hrpG// dependent (Song and Yang, 2010).
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 === Regulation === === Regulation ===
  
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 qRT-PCR revealed that transcript levels of 15 out of 18 tested non-TAL effector genes (as well as the regulatory genes //hrpG// and //hrpX//), including //xopZ//, were significantly reduced in the //Xanthomonas oryzae// pv. //oryzae// Δ//xrvC// mutant compared with those in the wild-type strain PXO99<sup>A</sup>  (Liu //et al.//, 2016). qRT-PCR revealed that transcript levels of 15 out of 18 tested non-TAL effector genes (as well as the regulatory genes //hrpG// and //hrpX//), including //xopZ//, were significantly reduced in the //Xanthomonas oryzae// pv. //oryzae// Δ//xrvC// mutant compared with those in the wild-type strain PXO99<sup>A</sup>  (Liu //et al.//, 2016).
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 === Phenotypes === === Phenotypes ===
  
-PXO99<sup>A</sup>  contains two identical copies of the gene due to a duplication of 212 kb in the genome. However, a deletion of one //xopZ// gene did not affect pathogenicity or bacterial growth in plants, while strains with mutations in both copies of //xopZ// <sub>PXO99</sub> displayed reduced virulence in terms of lesion length and bacterial multiplication compared with the wild type strain PXO99<sup>A</sup>  . The introduction of one genomic copy of //xopZ// <sub>PXO99</sub> restores the mutant to full virulence. To test whether XopZ<sub>PXO99</sub> inhibits the host cell-wall-associated defense responses (PTI), leaves of //Nicotiana benthamiana// were infiltrated with //Agrobacterium// cells with and without //xopZ// <sub>PXO99</sub> under the control of the cauliflower mosaic virus 35S promoter 24 hours preceding inoculation of the same leaves with a T3SS mutant of PXO99<sup>A</sup>  (ME7). Twenty-four hours after inoculation, leaves inoculated with ME7 had more callose depositions than the leaves inoculated with //Agrobacterium// spp. expressing //xopZ// <sub>PXO99</sub>. This results suggesting a role for XopZ<sub>PXO99</sub> in interfering with host innate immunity (PTI) during //X. oryzae// pv. //oryzae// infection (Song //et al.//, 2010). Besides, Western blot analysis with p44/42 MAP kinase antibody clearly showed that XopN, XopV and XopZ inhibited the peptidoglycan(PNG)-induced phosphorylation of OsMAPKs. Expression of all Xop effectors were verified by immunoblotting with anti-HA antibody. Thus, expression of three Xop effectors from PXO99<sup>A</sup>  in rice protoplasts results in compromised OsMAPK activation induced by PGN, highlighting their putative virulence functions during pathogenesis (Long //et al.//, 2018).+PXO99<sup>A</sup>  contains two identical copies of the gene due to a duplication of 212 kb in the genome. However, a deletion of one //xopZ// gene did not affect pathogenicity or bacterial growth in plants, while strains with mutations in both copies of //xopZ// <sub>PXO99</sub> displayed reduced virulence in terms of lesion length and bacterial multiplication compared with the wild type strain PXO99<sup>A</sup> . The introduction of one genomic copy of //xopZ// <sub>PXO99</sub> restores the mutant to full virulence. To test whether XopZ<sub>PXO99</sub> inhibits the host cell-wall-associated defense responses (PTI), leaves of //Nicotiana benthamiana// were infiltrated with //Agrobacterium// cells with and without //xopZ// <sub>PXO99</sub> under the control of the cauliflower mosaic virus 35S promoter 24 hours preceding inoculation of the same leaves with a T3SS mutant of PXO99<sup>A</sup>  (ME7). Twenty-four hours after inoculation, leaves inoculated with ME7 had more callose depositions than the leaves inoculated with //Agrobacterium// spp. expressing //xopZ// <sub>PXO99</sub>. This results suggesting a role for XopZ<sub>PXO99</sub> in interfering with host innate immunity (PTI) during //X. oryzae// pv. //oryzae// infection (Song //et al.//, 2010). Besides, Western blot analysis with p44/42 MAP kinase antibody clearly showed that XopN, XopV and XopZ inhibited the peptidoglycan(PNG)-induced phosphorylation of OsMAPKs. Expression of all Xop effectors were verified by immunoblotting with anti-HA antibody. Thus, expression of three Xop effectors from PXO99<sup>A</sup>  in rice protoplasts results in compromised OsMAPK activation induced by PGN, highlighting their putative virulence functions during pathogenesis (Long //et al.//, 2018).
  
 A role of XopZ in full virulence was also clearly shown in //Xanthomonas axonopodis// pv. //manihotis// CIO151 but not in PTI or ETI supression, at least under the tested conditions, as on the contrary to XopZ of //X. oryzae// pv. //oryzae// PXO99, no reduction of callose deposition was observed (Medina //et al.//, 2017). A role of XopZ in full virulence was also clearly shown in //Xanthomonas axonopodis// pv. //manihotis// CIO151 but not in PTI or ETI supression, at least under the tested conditions, as on the contrary to XopZ of //X. oryzae// pv. //oryzae// PXO99, no reduction of callose deposition was observed (Medina //et al.//, 2017).
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 === Localization === === Localization ===
  
 XopZ<sub>PXO99</sub> localizes in the cytoplasm and nucleus of the plant cell (Zhou //et al.//, 2015). XopZ<sub>PXO99</sub> localizes in the cytoplasm and nucleus of the plant cell (Zhou //et al.//, 2015).
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 === Enzymatic function === === Enzymatic function ===
  
 XopZ<sub>PXO99</sub> functions as a suppressor of LipA-induced innate immune responses since the mutation of //XopZ// partially compromises virulence while quadruple mutant of //xopN/xopQ/xopX/xopZ// induces calloses deposition just similarly to //Xoo// T3SS-mutant in rice leaves (Sinha //et al.//, 2013). The function of XopZ is also to stabilize a putative host E3 ubiquitin ligase protein PBP (s-ribonuclease) in the nucleus and prevents its degradation-mediated by a cysteine protease (C1A) in plant cells. XopZ may function to interfere with the homeostatic state of the negative regulator (PBP) in immune system in rice, and subvert the plant immune response (Zhou //et al.//, 2015). XopZ<sub>PXO99</sub> functions as a suppressor of LipA-induced innate immune responses since the mutation of //XopZ// partially compromises virulence while quadruple mutant of //xopN/xopQ/xopX/xopZ// induces calloses deposition just similarly to //Xoo// T3SS-mutant in rice leaves (Sinha //et al.//, 2013). The function of XopZ is also to stabilize a putative host E3 ubiquitin ligase protein PBP (s-ribonuclease) in the nucleus and prevents its degradation-mediated by a cysteine protease (C1A) in plant cells. XopZ may function to interfere with the homeostatic state of the negative regulator (PBP) in immune system in rice, and subvert the plant immune response (Zhou //et al.//, 2015).
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 === Interaction partners === === Interaction partners ===
  
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 === In xanthomonads === === In xanthomonads ===
  
-Yes, found to be conserved in all //Xanthomonas//spp. (whose genomes have been sequenced) with the exception of some clade-1 strains (//e.g.// //X. albilineans//) (Song and Yang, 2010; Sinha //et al.//, 2013).+Yes, found to be conserved in all //Xanthomonas //spp. (whose genomes have been sequenced) with the exception of some clade-1 strains (//e.g.////X. albilineans//) (Song and Yang, 2010; Sinha //et al.//, 2013). 
 === In other plant pathogens/symbionts === === In other plant pathogens/symbionts ===
  
 Related genes are also found in several //Pseudomonas syringae// pathovars (HopAs1 relatives), a few strains of //Ralstonia solanacearum// (AWR proteins), and the AAC00-1 strain of //Acidovorax avenae// subsp. //citrulli// (Song and Yang, 2010). Related genes are also found in several //Pseudomonas syringae// pathovars (HopAs1 relatives), a few strains of //Ralstonia solanacearum// (AWR proteins), and the AAC00-1 strain of //Acidovorax avenae// subsp. //citrulli// (Song and Yang, 2010).
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 ===== References ===== ===== References =====
  
bacteria/t3e/xopz.1734359536.txt.gz · Last modified: 2024/12/16 14:32 by rkoebnik