10.1371/journal.pgen.1005190
Louis S. Ates
Louis
S. Ates
Roy Ummels
Roy
Ummels
Susanna Commandeur
Susanna
Commandeur
Robert van der Weerd
Robert
van der Weerd
Marion Sparrius
Marion
Sparrius
Eveline Weerdenburg
Eveline
Weerdenburg
Marina Alber
Marina
Alber
Rainer Kalscheuer
Rainer
Kalscheuer
Sander R. Piersma
Sander R.
Piersma
Abdallah M. Abdallah
Abdallah
M. Abdallah
Moataz Abd El Ghany
Moataz
Abd El Ghany
Alyaa M. Abdel-Haleem
Alyaa
M. Abdel-Haleem
Arnab Pain
Arnab
Pain
Connie R. Jiménez
Connie
R. Jiménez
Wilbert Bitter
Wilbert
Bitter
Edith N.G. Houben
Edith
N.G. Houben
Essential Role of the ESX-5 Secretion System in Outer Membrane Permeability of Pathogenic Mycobacteria
Public Library of Science
2015
membrane ATPase EccC 5
pe
substrate
T 7S systems
Outer Membrane Permeability
carbon sources
cell envelope fractions
type VII secretion
Subsequent proteomic analysis
cell envelope proteins
heterologous porin MspA
ppe
esx
Pathogenic Mycobacteria Mycobacteria
2015-05-04 03:25:37
Dataset
https://plos.figshare.com/articles/dataset/_Essential_Role_of_the_ESX_5_Secretion_System_in_Outer_Membrane_Permeability_of_Pathogenic_Mycobacteria_/1402948
<div><p>Mycobacteria possess different type VII secretion (T7S) systems to secrete proteins across their unusual cell envelope. One of these systems, ESX-5, is only present in slow-growing mycobacteria and responsible for the secretion of multiple substrates. However, the role of ESX-5 substrates in growth and/or virulence is largely unknown. In this study, we show that <i>esx-5</i> is essential for growth of both <i>Mycobacterium marinum</i> and <i>Mycobacterium bovis</i>. Remarkably, this essentiality can be rescued by increasing the permeability of the outer membrane, either by altering its lipid composition or by the introduction of the heterologous porin MspA. Mutagenesis of the first nucleotide-binding domain of the membrane ATPase EccC<sub>5</sub> prevented both ESX-5-dependent secretion and bacterial growth, but did not affect ESX-5 complex assembly. This suggests that the rescuing effect is not due to pores formed by the ESX-5 membrane complex, but caused by ESX-5 activity. Subsequent proteomic analysis to identify crucial ESX-5 substrates confirmed that all detectable PE and PPE proteins in the cell surface and cell envelope fractions were routed through ESX-5. Additionally, saturated transposon-directed insertion-site sequencing (TraDIS) was applied to both wild-type <i>M</i>. <i>marinum</i> cells and cells expressing <i>mspA</i> to identify genes that are not essential anymore in the presence of MspA. This analysis confirmed the importance of <i>esx-5</i>, but we could not identify essential ESX-5 substrates, indicating that multiple of these substrates are together responsible for the essentiality. Finally, examination of phenotypes on defined carbon sources revealed that an <i>esx-5</i> mutant is strongly impaired in the uptake and utilization of hydrophobic carbon sources. Based on these data, we propose a model in which the ESX-5 system is responsible for the transport of cell envelope proteins that are required for nutrient uptake. These proteins might in this way compensate for the lack of MspA-like porins in slow-growing mycobacteria.</p></div>