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bacteria:t3e:xopl

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bacteria:t3e:xopl [2025/11/05 08:36] – [Biological function] jfpothierbacteria:t3e:xopl [2025/11/05 16:24] (current) jfpothier
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 === How discovered? === === How discovered? ===
  
-XopL was first identified in //X. campestris// pv. //campestris// (//Xcc//) strain 8004 as a candidate T3E due to the presence of a plant-inducible promoter (PIP) box upstream of the CDS, //XC_4273// (Jiang //et al.//, 2009). The CDS //XC_4273//, re-called XopXccLR (LR = leucine-rich repeat) or XopL<sub>Xcc</sub> for the purposes of this article, in //Xcc// 8004 was suggested to be a T3E as it harboured a N-terminal region possessing a translocation signal that was able to target proteins into plant cells (Jiang //et al.//, 2009). It was also shown to be required for //Xcc// proliferation in hosts plant (Jiang //et al.//, 2009). It was only a few years later that the analysis of the genome sequence of //X.// //campestris// pv. //vesicatoria// (//Xcv//) strain 85-10 (synonymous with //X. euvesicatoria// 85-10; //Xe// 85-10) led to the identification of XCV3220 (//xopL<sub>Xe</sub>//) as a new T3E candidate gene and to its more complete characterization (Singer //et al//., 2013). XopL<sub>Xe</sub> was shown to have E3 ubiquitin ligase activity, conferred by a ligase domain with a novel fold (XL-box), capable of interacting with the plant host ubiquitination cascade (Singer //et al.//, 2023).+XopL was first identified in //X. campestris// pv. //campestris// (//Xcc//) strain 8004 as a candidate T3E due to the presence of a plant-inducible promoter (PIP) box upstream of the CDS, //XC_4273// (Jiang //et al.//, 2009). The CDS //XC_4273//, re-called XopXccLR (LR = leucine-rich repeat) or XopL<sub>Xcc</sub> for the purposes of this article, in //Xcc// 8004 was suggested to be a T3E as it harboured a N-terminal region possessing a translocation signal that was able to target proteins into plant cells (Jiang //et al.//, 2009). It was also shown to be required for //Xcc// proliferation in hosts plant (Jiang //et al.//, 2009). It was only a few years later that the analysis of the genome sequence of //X. campestris// pv. //vesicatoria// (//Xcv//) strain 85-10 (synonymous with //X. euvesicatoria// 85-10; //Xe// 85-10) led to the identification of XCV3220 (//xopL<sub>Xe</sub>//) as a new T3E candidate gene and to its more complete characterization (Singer //et al//., 2013). XopL<sub>Xe</sub> was shown to have E3 ubiquitin ligase activity, conferred by a ligase domain with a novel fold (XL-box), capable of interacting with the plant host ubiquitination cascade (Singer //et al//., 2023).
  
 === (Experimental) evidence for being a T3E === === (Experimental) evidence for being a T3E ===
  
-XopL<sub>Xcc</sub> possesses features that are typical of T3Es: the promoter region of the //xopL<sub>Xcc</sub>// gene contains a perfect plant inducible promoter (PIP) box followed by a 10 box similar sequence (TTCGC-N<sub>15</sub>-TTCGC-N<sub>31</sub>-ACGACA) and an LRR motif characteristic of T3Es in pathogenic bacteria (Yan //et al//., 2019). Using an AvrBs1 reporter fusion, XopL<sub>Xcc</sub> was shown to be translocated into plant cells in a //hrpF-// and //hpaB//-dependent manner (Jiang //et al//., 2009). XopL<sub>Xe</sub> also contains a PIP box (plant inducible promoter) in its promoter (TTCG-N<sub>16</sub>-TTCG; genome position 3669238-261) and co-regulation with the T3S system was confirmed by RT-PCR (Singer //et al.//, 2013). Type III-dependent secretion and translocation was confirmed by //in vitro// secretion and //in vivo// translocation assays (Singer //et al.//, 2013).+XopL<sub>Xcc</sub> possesses features that are typical of T3Es: the promoter region of the //xopL<sub>Xcc</sub>// gene contains a perfect plant inducible promoter (PIP) box followed by a 10 box similar sequence (TTCGC-N<sub>15</sub>-TTCGC-N<sub>31</sub>-ACGACA) and an LRR motif characteristic of T3Es in pathogenic bacteria (Yan //et al//., 2019). Using an AvrBs1 reporter fusion, XopL<sub>Xcc</sub> was shown to be translocated into plant cells in a //hrpF-// and //hpaB//-dependent manner (Jiang //et al//., 2009). XopL<sub>Xe</sub> also contains a PIP box (plant inducible promoter) in its promoter (TTCG-N<sub>16</sub>-TTCG; genome position 3669238-261) and co-regulation with the T3S system was confirmed by RT-PCR (Singer //et al.//, 2013). Type III-dependent secretion and translocation was confirmed by //in vitro// secretion and //in vivo// translocation assays (Singer //et al//., 2013).
  
 === Regulation === === Regulation ===
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 The //xopL// <sub>Xcc8004</sub> gene contains a PIP box and was shown to be controlled by //hrpG// and //hrpX// (Jiang et al., 2009). The //xopL// <sub>Xcc8004</sub> gene contains a PIP box and was shown to be controlled by //hrpG// and //hrpX// (Jiang et al., 2009).
  
-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 //xopL//, 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 //xopL//, 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).
  
 The expression of //xopL<sub>Xcc</sub>// gene is positively regulated by HrpG/HrpX (Yan //et al//., 2019). The expression of //xopL<sub>Xcc</sub>// gene is positively regulated by HrpG/HrpX (Yan //et al//., 2019).
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 === Phenotypes === === Phenotypes ===
  
-  * XopL<sub>//Xe//</sub> from //X. euvesicatoria// 85-10 (previously referred to as //X. campestris// pv. //euvesicatoria//; //Xcv//) displays E3 ubiquitin ligase activity (Singer //et al.//, 2013). +  * XopL<sub>//Xe//</sub> from //X. euvesicatoria// 85-10 (previously referred to as //X. campestris// pv. //euvesicatoria//; //Xcv//) displays E3 ubiquitin ligase activity (Singer //et al//., 2013). 
-  * XopL//<sub>Xe</sub>// inhibits expression of the elf18- and flg22-induced defense gene pNHL10 in //Arabidopsis// mesophyll protoplasts independent of E3 ligase function (Singer //et al.//, 2013).+  * XopL//<sub>Xe</sub>// inhibits expression of the elf18- and flg22-induced defense gene pNHL10 in //Arabidopsis// mesophyll protoplasts independent of E3 ligase function (Singer //et al//., 2013).
   * XopL//<sub>Xe</sub>// suppresses ABA responsive reporter //pRD29b:GUS// and PTI reporter //pFRK1:LUC// in //Arabidopsis// protoplasts (Popov //et al//., 2016).   * XopL//<sub>Xe</sub>// suppresses ABA responsive reporter //pRD29b:GUS// and PTI reporter //pFRK1:LUC// in //Arabidopsis// protoplasts (Popov //et al//., 2016).
   * XopL//<sub>Xcc</sub>// interferes with innate immunity (Yan //et al.//, 2019; Huang //et al.//, 2024a) and SA signaling in //Arabidopsis// (Huang //et al.//, 2024).   * XopL//<sub>Xcc</sub>// interferes with innate immunity (Yan //et al.//, 2019; Huang //et al.//, 2024a) and SA signaling in //Arabidopsis// (Huang //et al.//, 2024).
bacteria/t3e/xopl.1762331768.txt.gz · Last modified: 2025/11/05 08:36 by jfpothier