Ca2+-dependent lipid binding and membrane integration of PopA, a harpin-like elicitor of the hypersensitive response in tobacco
type: Dataset
description: PopA is released by type III secretion from the bacterial plant pathogen Ralstonia solanacearum and triggers the hypersensitive response (HR) in tobacco. The function of PopA remains obscure, mainly because mutants lacking this protein are not altered in their ability to interact with plants. In an attempt to identify the site of PopA activity in plant cells, we generated transgenic tobacco plants expressing the popA gene under the control of an inducible promoter. Immunocytologic analysis revealed that the HR phenotype of these plants correlated with the presence of PopA at the plant plasma membrane. Membrane localization was observed irrespective of whether the protein was designed to accumulate in the cytoplasm or to be secreted by the plant cell, suggesting a general lipid-binding ability. We found that the protein had a high affinity for sterols and sphingolipids in vitro and that it required Ca2+ for both lipid binding and oligomerization. In addition, the protein was integrated into liposomes and membranes from Xenopus laevis oocytes where it formed ion-conducting pores. These characteristics suggest that PopA is part of a system that aims to attach the host cell plasma membrane and to allow molecules cross this barrier.
issued: 2026-05-09T12:32:03.779781
language: en
modified: 2026-05-09T12:32:03.779785
contact point: Organization
  fn: CCSD
keyword: bacterial-pathogenesis
keyword: effector-protein
keyword: iii-secretion-system
keyword: infoeu-reposemanticsarticle
keyword: journal-articles
keyword: plant-pathogen
keyword: programmed-cell-death
keyword: ralstonia-solanacearum
keyword: sdvbvlife-sciences-q-biovegetal-biology
keyword: secondary-structure
keyword: structure-prediction
keyword: transgenic-tobacco
keyword: yersinia-enterocolitica
landing page: 0950-382X

Ca2+-dependent lipid binding and membrane integration of PopA, a harpin-like elicitor of the hypersensitive response in tobacco
type: Distribution
format: HTML
issued: 2026-05-09T12:32:03.788137
modified: 2026-05-09T12:32:03.760761
access URL: https://hal.science/hal-00086888

test_moissonnage_selune
type: Agent