title: The outer membrane phospholipase A is essential for membrane integrity and type III secretion in Shigella flexneri.
abstract: Outer membrane phospholipase A (OMPLA) is an enzyme located in the outer membrane of Gram-negative bacteria. OMPLA exhibits broad substrate specificity, and some of its substrates are located in the cellular envelope. Generally, the enzymatic activity can only be induced by perturbation of the cell envelope integrity through diverse methods. Although OMPLA has been thoroughly studied as a membrane protein in Escherichia coli and is constitutively expressed in many other bacterial pathogens, little is known regarding the functions of OMPLA during the process of bacterial infection. In this study, the proteomic and transcriptomic data indicated that OMPLA in Shigella flexneri, termed PldA, both stabilizes the bacterial membrane and is involved in bacterial infection under ordinary culture conditions. A series of physiological assays substantiated the disorganization of the bacterial outer membrane and the periplasmic space in the ΔpldA mutant strain. Furthermore, the ΔpldA mutant strain showed decreased levels of type III secretion system expression, contributing to the reduced internalization efficiency in host cells. The results of this study support that PldA, which is widespread across Gram-negative bacteria, is an important factor for the bacterial life cycle, particularly in human pathogens.
authors.affiliation: MOH Key Laboratory of Systems Biology of Pathogens, Institute of Pathogen Biology, Chinese Academy of Medical Sciences and Peking Union Medical College, People's Republic of China.
authors.forename: Xia
authors.initials: X
authors.lastname: Wang
authors.affiliation: MOH Key Laboratory of Systems Biology of Pathogens, Institute of Pathogen Biology, Chinese Academy of Medical Sciences and Peking Union Medical College, People's Republic of China.
authors.forename: Feng
authors.initials: F
authors.lastname: Jiang
authors.affiliation: MOH Key Laboratory of Systems Biology of Pathogens, Institute of Pathogen Biology, Chinese Academy of Medical Sciences and Peking Union Medical College, People's Republic of China.
authors.forename: Jianhua
authors.initials: J
authors.lastname: Zheng
authors.affiliation: MOH Key Laboratory of Systems Biology of Pathogens, Institute of Pathogen Biology, Chinese Academy of Medical Sciences and Peking Union Medical College, People's Republic of China.
authors.forename: Lihong
authors.initials: L
authors.lastname: Chen
authors.affiliation: MOH Key Laboratory of Systems Biology of Pathogens, Institute of Pathogen Biology, Chinese Academy of Medical Sciences and Peking Union Medical College, People's Republic of China.
authors.forename: Jie
authors.initials: J
authors.lastname: Dong
authors.affiliation: MOH Key Laboratory of Systems Biology of Pathogens, Institute of Pathogen Biology, Chinese Academy of Medical Sciences and Peking Union Medical College, People's Republic of China.
authors.forename: Lilian
authors.initials: L
authors.lastname: Sun
authors.affiliation: MOH Key Laboratory of Systems Biology of Pathogens, Institute of Pathogen Biology, Chinese Academy of Medical Sciences and Peking Union Medical College, People's Republic of China.
authors.forename: Yafang
authors.initials: Y
authors.lastname: Zhu
authors.affiliation: MOH Key Laboratory of Systems Biology of Pathogens, Institute of Pathogen Biology, Chinese Academy of Medical Sciences and Peking Union Medical College, People's Republic of China.
authors.forename: Bo
authors.initials: B
authors.lastname: Liu
authors.affiliation: MOH Key Laboratory of Systems Biology of Pathogens, Institute of Pathogen Biology, Chinese Academy of Medical Sciences and Peking Union Medical College, People's Republic of China.
authors.forename: Jian
authors.initials: J
authors.lastname: Yang
authors.affiliation: MOH Key Laboratory of Systems Biology of Pathogens, Institute of Pathogen Biology, Chinese Academy of Medical Sciences and Peking Union Medical College, People's Republic of China zdsys@vip.sina.com.
authors.forename: Guowei
authors.initials: G
authors.lastname: Yang
authors.affiliation: MOH Key Laboratory of Systems Biology of Pathogens, Institute of Pathogen Biology, Chinese Academy of Medical Sciences and Peking Union Medical College, People's Republic of China yangguowei@hotmail.com.
authors.forename: Qi
authors.identifier: http://orcid.org/0000-0002-3586-6344
authors.initials: Q
authors.lastname: Jin
keywords: Shigella flexneri; cell membranes; host cell invasion; phospholipase A