title: A Pseudomonas T6SS effector recruits PQS-containing outer membrane vesicles for iron acquisition.
abstract: Iron sequestration by host proteins contributes to the defence against bacterial pathogens, which need iron for their metabolism and virulence. A Pseudomonas aeruginosa mutant lacking all three known iron acquisition systems retains the ability to grow in media containing iron chelators, suggesting the presence of additional pathways involved in iron uptake. Here we screen P. aeruginosa mutants defective in growth in iron-depleted media and find that gene PA2374, proximal to the type VI secretion system H3 (H3-T6SS), functions synergistically with known iron acquisition systems. PA2374 (which we have renamed TseF) appears to be secreted by H3-T6SS and is incorporated into outer membrane vesicles (OMVs) by directly interacting with the iron-binding Pseudomonas quinolone signal (PQS), a cell-cell signalling compound. TseF facilitates the delivery of OMV-associated iron to bacterial cells by engaging the Fe(III)-pyochelin receptor FptA and the porin OprF. Our results reveal links between type VI secretion, cell-cell signalling and classic siderophore receptors for iron acquisition in P. aeruginosa.
authors.affiliation: State Key Laboratory of Crop Stress Biology for Arid Areas and College of Life Sciences, Northwest A&F University, Yangling, Shaanxi 712100, China.|Shaanxi Engineering &Technological Research Center for Conversation &Utilization of Regional Biological Resources, College of Life Sciences, Yan'an University, Yan'an, Shaanxi 716000, China.
authors.forename: Jinshui
authors.initials: J
authors.lastname: Lin
authors.affiliation: State Key Laboratory of Crop Stress Biology for Arid Areas and College of Life Sciences, Northwest A&F University, Yangling, Shaanxi 712100, China.|Division of Life Science, Hong Kong University of Science and Technology, Clear Water Bay, Hong Kong.
authors.forename: Weipeng
authors.initials: W
authors.lastname: Zhang
authors.affiliation: State Key Laboratory of Crop Stress Biology for Arid Areas and College of Life Sciences, Northwest A&F University, Yangling, Shaanxi 712100, China.|Shaanxi Engineering &Technological Research Center for Conversation &Utilization of Regional Biological Resources, College of Life Sciences, Yan'an University, Yan'an, Shaanxi 716000, China.
authors.forename: Juanli
authors.initials: J
authors.lastname: Cheng
authors.affiliation: State Key Laboratory of Crop Stress Biology for Arid Areas and College of Life Sciences, Northwest A&F University, Yangling, Shaanxi 712100, China.
authors.forename: Xu
authors.initials: X
authors.lastname: Yang
authors.affiliation: State Key Laboratory of Crop Stress Biology for Arid Areas and College of Life Sciences, Northwest A&F University, Yangling, Shaanxi 712100, China.
authors.forename: Kaixiang
authors.initials: K
authors.lastname: Zhu
authors.affiliation: State Key Laboratory of Crop Stress Biology for Arid Areas and College of Life Sciences, Northwest A&F University, Yangling, Shaanxi 712100, China.
authors.forename: Yao
authors.initials: Y
authors.lastname: Wang
authors.affiliation: State Key Laboratory of Crop Stress Biology for Arid Areas and College of Life Sciences, Northwest A&F University, Yangling, Shaanxi 712100, China.
authors.forename: Gehong
authors.initials: G
authors.lastname: Wei
authors.affiliation: Division of Life Science, Hong Kong University of Science and Technology, Clear Water Bay, Hong Kong.
authors.forename: Pei-Yuan
authors.initials: PY
authors.lastname: Qian
authors.affiliation: Purdue Institute of Immunology, Inflammation and Infectious Diseases and the Department of Biological Sciences, Purdue University, 915 West State Street, West Lafayette, Indiana 47907, USA.
authors.forename: Zhao-Qing
authors.initials: ZQ
authors.lastname: Luo
authors.affiliation: State Key Laboratory of Crop Stress Biology for Arid Areas and College of Life Sciences, Northwest A&F University, Yangling, Shaanxi 712100, China.
authors.forename: Xihui
authors.initials: X
authors.lastname: Shen
mesh_terms: D000595:Amino Acid Sequence; D001425:Bacterial Outer Membrane Proteins / Q000378:metabolism; D001426:Bacterial Proteins / Q000737:chemistry / Q000378:metabolism*; D058947:Bacterial Secretion Systems; D002462:Cell Membrane / Q000378:metabolism*; D007501:Iron / Q000378:metabolism*; D008954:Models, Biological; D009154:Mutation / Q000235:genetics; D011550:Pseudomonas aeruginosa / Q000235:genetics / Q000254:growth & development / Q000378:metabolism*; D015363:Quinolones / Q000378:metabolism*; D011956:Receptors, Cell Surface / Q000378:metabolism; D013379:Substrate Specificity; D022161:Transport Vesicles / Q000378:metabolism*
chemical_list: C407944:2-heptyl-3-hydroxy-4-quinolone; D001425:Bacterial Outer Membrane Proteins; D001426:Bacterial Proteins; D058947:Bacterial Secretion Systems; D015363:Quinolones; D011956:Receptors, Cell Surface; C035902:siderophore receptors; D007501:Iron