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bacteria:t3e:xopaa

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bacteria:t3e:xopaa [2023/12/07 11:21] – [Biological function] rkoebnikbacteria:t3e:xopaa [2025/02/12 23:09] (current) jfpothier
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-====== XopAA ======+====== The Type III Effector XopAA from //Xanthomonas// ======
  
-Author: John Doe\\ +Author: [[https://www.researchgate.net/profile/Ralf-Koebnik|Ralf Koebnik]]
-Internal reviewerJane Doe \\ +
-Expert reviewer: **WANTED!**+
  
 Class: XopAA\\ Class: XopAA\\
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 Although //Xee// <sub>75-3</sub> induced chlorosis on susceptible tomato lines, none of the 75-3 //hrp// mutants tested induced a chlorotic response on tomato. This result suggested the possibility that XopAA is normally translocated by the Hrp T3SS into host cells (Morales //et al.//, 2005). Although //Xee// <sub>75-3</sub> induced chlorosis on susceptible tomato lines, none of the 75-3 //hrp// mutants tested induced a chlorotic response on tomato. This result suggested the possibility that XopAA is normally translocated by the Hrp T3SS into host cells (Morales //et al.//, 2005).
 +
 +Transient expression of //xopAA// //in planta// using an //Agrobacterium tumefaciens//-mediated expression system induced a chlorotic phenotype independent of //Xanthomonas//, This demonstration that //xopAA// induces chlorosis when directly expressed by the host cell suggested that the loss of chlorosis induction in the //hrp// mutants was a direct effect of preventing T3SS-dependent translocation (Morales //et al.//, 2005).
 +
 +//Xanthomonas// bacteria carrying a translational fusion of XopAA to the calmodulin-dependent adenylate cyclase Cya produced approximately 30 times more cAMP in tomato leaves at 8 hpi when compared to bacteria with a mutation in the T3SS gene //hrcV// or bacteria that harbour a //recA//://cya// fusion. These results indicated that the //xopAA// gene product is translocated to host cells in a T3SS-dependent manner (Morales //et al.//, 2005).
 === Regulation === === Regulation ===
  
 +RT-PCR expression analyses suggested that, although translocation of XopAA is dependent on the Hrp T3SS apparatus, //xopAA// expression does not depend on nutritional conditions that induce //hrp// gene expression in //Xee// (Morales //et al.//, 2005).
 === Phenotypes === === Phenotypes ===
  
-=== Localization ===+Transgenic rice plants expressing XopAA//<sub>Xoo</sub>// exhibited semi-dwarfism and a reduction in Brassinolide-dependent laminar inclination, characteristics of brassinosteroid (BR)-insensitive mutants caused by mutations of the BR receptor (Yamaguchi //et al.//, 2013).
  
-=== Enzymatic function ===+Rice plants inoculated with a T3SS-deficient //hrpX// mutant of //X. oryzae// pv. //oryzae// (//Xoo//) did not develop disease lesions. In contrast, a transgenic rice line overexpressing //xopAA// showed severe lesions when inoculated with the //Xoo// //hrpX// mutant and the bacterial population of the //hrpX// mutant was 100-fold higher in the transgenic plants than in wild-type plants. This observation led the authors conclude that XopAA<sub>//Xoo//</sub> inhibits resistance to //Xoo//, which was probably caused by suppression of host PTI (Yamaguchi //et al.//, 2013). However, a //xopAA// knock-out strain of //Xoo// did not exhibit any defect in virulence (Yamaguchi //et al.//, 2013).
  
-=== Interaction partners ===+Expression of XopAA<sub>//Xoo//</sub> in //Arabidopsis// cells activated host immune responses, suggesting the presence of intracellular immune receptors that recognize XopAA (Yamaguchi //et al.//, 2013).
  
-===== Conservation =====+//Xanthomonas oryzae// pv. //oryzicola// bacteria with a deletion of //xopAA// were found to cause enhanced virulence to a certain rice cultivar (Li //et al.//, 2015). 
 +=== Localization ===
  
-=== In xanthomonads ===+Unknown.
  
-=== In other plant pathogens/symbionts ===+=== Enzymatic function ===
  
-===== Biological function =====+Unknown.
  
-=== How discovered? ===+=== Interaction partners ===
  
-=== (Experimentalevidence for being a T3E === +A yeast two-hybrid experiment indicated that XopAA<sub>//Xoo//</sub> interacted with OsBAK1, an essential component of both microbe-associated molecular patterns (MAMPsand BR receptors, suggesting that the virulent activity of XopAA is mediated by inhibition of OsBAK1 (Yamaguchi //et al.//, 2013).
- +
-=== Regulation === +
- +
-=== Phenotypes === +
- +
-=== Localization === +
- +
-=== Enzymatic function === +
- +
-=== Interaction partners ===+
  
 ===== Conservation ===== ===== Conservation =====
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 === In xanthomonads === === In xanthomonads ===
  
-DNA hybridization experiments suggested that //xopAA// is highly specific to //Xee// (Morales //et al//., 2005).+DNA hybridization experiments had suggested that //xopAA// might be highly specific to //Xee// (Morales //et al//., 2005). However, genomic comparisons showed that xopAA homologs are present in other xanthomonads, such as //X. hortorum//, //X. hydrangeae//, //X. oryzae//, //X. populi//, //X. translucens//, and //X. vasicola//.
 === In other plant pathogens/symbionts === === In other plant pathogens/symbionts ===
 +
 +Yes (//Mesorhizobium//). Weak homology (ca 25% sequence identity) to proteins in //Erwinia// and //Pseudomonas// (HopAE1/HopW family)
  
 ===== References ===== ===== References =====
bacteria/t3e/xopaa.1701948115.txt.gz · Last modified: 2023/12/07 11:21 by rkoebnik