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bacteria:t3e:xopp

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bacteria:t3e:xopp [2025/07/04 23:44] jfpothierbacteria:t3e:xopp [2025/07/24 22:48] (current) jfpothier
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 === (Experimental) evidence for being a T3E === === (Experimental) evidence for being a T3E ===
  
-Type III-dependent secretion was confirmed using a calmodulin-dependent adenylate cyclase reporter assay, with a Δ//hrpF// mutant strain serving as negative control (Roden //et al.//, 2004). Using an AvrBs1 reporter fusion, XopP<sub>Xcc8004</sub> was shown to be translated into plant cells in a //hrpF//- and //hpaB//-dependent manner (Jiang //et al.//, 2009). XopR<sub>//Xoo// </sub> was confirmed to have a functional type III secretion signal using a reporter fusion with AvrBs1 (Zhao //et al.//, 2013).+Type III-dependent secretion was confirmed using a calmodulin-dependent adenylate cyclase reporter assay, with a Δ//hrpF// mutant strain serving as negative control (Roden //et al.//, 2004). Using an AvrBs1 reporter fusion, XopP<sub>Xcc8004</sub> was shown to be translated into plant cells in a //hrpF//- and //hpaB//-dependent manner (Jiang //et al.//, 2009). XopR<sub>//Xoo//</sub> was confirmed to have a functional type III secretion signal using a reporter fusion with AvrBs1 (Zhao //et al.//, 2013).
  
 === Regulation === === Regulation ===
  
-The //xopP// <sub>Xcc8004</sub> gene contains a PIP box and was shown to be controlled by //hrpG// and //hrpX// (Jiang et al., 2009).+The //xopP//<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 //xopP//, 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 //xopP//, 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).
  
 === Phenotypes === === Phenotypes ===
  
-  * Roden //et al.//  did not find significant growth defects of a //Xcv//  Δ//xopP//  mutant in susceptible pepper and tomato leaves (Roden et al., 2004). +  * Roden //et al.// did not find significant growth defects of a //Xcv// Δ//xopP// mutant in susceptible pepper and tomato leaves (Roden et al., 2004). 
-  * XopQ<sub>Xcc8004</sub>  is required for full virulence and growth of //X. campestris//  pv. //campestris//  in the host plant Chinese radish (Jiang //et al.//, 2009). +  * XopQ<sub>Xcc8004</sub> is required for full virulence and growth of //X. campestris// pv. //campestris// in the host plant Chinese radish (Jiang //et al.//, 2009). 
-  * XopP<sub>Xoo</sub>  is able to suppress rice pathogen associated molecular pattern (PAMP)-immunity and resistance to //Xanthomonas oryzae//  pv. //oryzae//. Although XopP<sub>Xoo</sub>  is classified within the XopP, it shows only 40% sequence identity with the XopP homologue of //X. campestris//  pv. //campestris//  (Furutani //et al//., 2009). Therefore, it remains unclear if such interaction is similar in different pathosystems where XopP has been found. +  * XopP<sub>Xoo</sub> is able to suppress rice pathogen associated molecular pattern (PAMP)-immunity and resistance to //Xanthomonas oryzae// pv. //oryzae//. Although XopP<sub>Xoo</sub> is classified within the XopP, it shows only 40% sequence identity with the XopP homologue of //X. campestris// pv. //campestris// (Furutani //et al//., 2009). Therefore, it remains unclear if such interaction is similar in different pathosystems where XopP has been found. 
-  * //Agrobacterium//-mediated transient expression of both XopQ and XopX in rice cells resulted in induction of rice immune responses, which were not observed when either protein was individually expressed. A screen for //Xanthomonas//  effectors which can suppress XopQ-XopX induced rice immune responses, led to the identification of five effectors, namely XopU, XopV, XopP, XopG and AvrBs2, that could individually suppress these immune responses. These results suggest a complex interplay of //Xanthomonas//  T3SS effectors in suppression of both pathogen-triggered immunity and effector-triggered immunity to promote virulence on rice (Deb //et al.//, 2020). +  * //Agrobacterium//-mediated transient expression of both XopQ and XopX in rice cells resulted in induction of rice immune responses, which were not observed when either protein was individually expressed. A screen for //Xanthomonas// effectors which can suppress XopQ-XopX induced rice immune responses, led to the identification of five effectors, namely XopU, XopV, XopP, XopG and AvrBs2, that could individually suppress these immune responses. These results suggest a complex interplay of //Xanthomonas// T3SS effectors in suppression of both pathogen-triggered immunity and effector-triggered immunity to promote virulence on rice (Deb //et al.//, 2020). 
-  * XopP inhibits the function of the host-plant exocyst complex by direct targeting of Exo70B, a subunit of the exocyst complex, which plays a significant role in plant immunity. XopP interferes with exocyst-dependent exocytosis, and can do this without activating a plant NLR (NOD-like receptor) that guards Exo70B in Arabidopsis. In this way, //Xanthomonas//  efficiently inhibits the host's pathogen-associated molecular pattern (PAMP)-triggered immunity (PTI) by blocking exocytosis of pathogenesis-related protein-1A (PR1a), callose deposition and localization of the FLS2 immune receptor to the plasma membrane, thus promoting successful infection (Michalopoulou //et al.//, 2022). +  * XopP inhibits the function of the host-plant exocyst complex by direct targeting of Exo70B, a subunit of the exocyst complex, which plays a significant role in plant immunity. XopP interferes with exocyst-dependent exocytosis, and can do this without activating a plant NLR (NOD-like receptor) that guards Exo70B in Arabidopsis. In this way, //Xanthomonas// efficiently inhibits the host's pathogen-associated molecular pattern (PAMP)-triggered immunity (PTI) by blocking exocytosis of pathogenesis-related protein-1A (PR1a), callose deposition and localization of the FLS2 immune receptor to the plasma membrane, thus promoting successful infection (Michalopoulou //et al.//, 2022). 
-  * Using biophysical, biochemical, and molecular assays in combination with structural and functional predictions, utilizing AplhaFold and DALI online, it was shown that XopP<sub>Xcc</sub>  functions as a novel serine/threonine kinase upon its host target AtExo70B1 but also protects the latter from the innate AtCPK5 phosphorylation, in order to bypass the host’s immune responses (Kotsaridis //et al.//, 2023).+  * Using biophysical, biochemical, and molecular assays in combination with structural and functional predictions, utilizing AplhaFold and DALI online, it was shown that XopP<sub>Xcc</sub> functions as a novel serine/threonine kinase upon its host target AtExo70B1 but also protects the latter from the innate AtCPK5 phosphorylation, in order to bypass the host’s immune responses (Kotsaridis //et al.//, 2023).
  
 === Localization === === Localization ===
  
-XopP<sub>Xoo</sub>  co-localizes with OsPUB44 in the cytoplasm (Ishikawa //et al//., 2014).+XopP<sub>Xoo</sub> co-localizes with OsPUB44 in the cytoplasm (Ishikawa //et al//., 2014).
  
 === Enzymatic function === === Enzymatic function ===
  
-XopP<sub>Xcc</sub>  functions as a novel serine/threonine kinase upon its host target AtExo70B1, which gets phosphorylated at Ser107, Ser111, Ser248, Thr309, and Thr364 (Kotsaridis //et al.//, 2023).+XopP<sub>Xcc</sub> functions as a novel serine/threonine kinase upon its host target AtExo70B1, which gets phosphorylated at Ser107, Ser111, Ser248, Thr309, and Thr364 (Kotsaridis //et al.//, 2023).
  
 === Interaction partners === === Interaction partners ===
  
-XopP<sub>Xoo</sub>  interacts with the U-box domain of a rice ubiquitin E3 ligase, OsPUB44 and inhibits its activity (Ishikawa //et al//., 2014). XopP<sub>Xcc</sub>  interacts with EXO70B1, EXO70B2 and EXO70F1 in a yeast two-hybrid assay (Michalopoulou //et al.//, 2022). Interaction was confirmed in planta by split YFP and coIP assays (Michalopoulou //et al.//, 2022).+XopP<sub>Xoo</sub> interacts with the U-box domain of a rice ubiquitin E3 ligase, OsPUB44 and inhibits its activity (Ishikawa //et al//., 2014). XopP<sub>Xcc</sub> interacts with EXO70B1, EXO70B2 and EXO70F1 in a yeast two-hybrid assay (Michalopoulou //et al.//, 2022). Interaction was confirmed in planta by split YFP and coIP assays (Michalopoulou //et al.//, 2022).
  
 ===== Conservation ===== ===== Conservation =====
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 === In xanthomonads === === In xanthomonads ===
  
-Yes (//e.g.//, //X. campestris//, //X. citri//, //X. euvesicatoria//, //X. oryzae//, //X. translucens//). Since the G+C content of the //xopP//  gene is similar to that of the //Xcv//  //hrp//  gene cluster, it may be a member of a “core” group of //Xanthomonas//  spp. effectors (Roden et al., 2004).+Yes (//e.g.//, //X. campestris//, //X. citri//, //X. euvesicatoria//, //X. oryzae//, //X. translucens//). Since the G+C content of the //xopP// gene is similar to that of the //Xcv// //hrp// gene cluster, it may be a member of a “core” group of //Xanthomonas// spp. effectors (Roden et al., 2004).
  
 === In other plant pathogens/symbionts === === In other plant pathogens/symbionts ===
bacteria/t3e/xopp.txt · Last modified: 2025/07/24 22:48 by jfpothier