The Burkholderia pseudomallei proteins BapA and BapC are secreted TTSS3 effectors and BapB levels modulate expression of BopE

Puthayalai Treerat, Priyangi A Alwis, Tanya M D'Cruze, Meabh Cullinane, Jamunarani Vadivelu, Rodney J Devenish, Mark Prescott, Ben Adler, John D Boyce

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2 Citations (Scopus)

Abstract

Many Gram-negative pathogens use a type III secretion system (TTSS) for the injection of bacterial effector proteins into host cells. The injected effector proteins play direct roles in modulation of host cell pathways for bacterial benefit. Burkholderia pseudomallei, the causative agent of melioidosis, expresses three different TTSSs. One of these systems, the TTSS3, is essential for escape from host endosomes and therefore intracellular survival and replication. Here we have characterized three putative TTSS3 proteins; namely BapA, BapB and BapC. By employing a tetracysteine (TC)-FlAsH labelling technique to monitor the secretion of TC-tagged fusion proteins, BapA and BapC were shown to be secreted during in vitro growth in a TTSS3-dependant manner, suggesting a role as TTSS3 effectors. Furthermore, we constructed B. pseudomallei bapA, bapB and bapC mutants and used the well-characterized TTSS3 effector BopE as a marker of secretion to show that BapA, BapB and BapC are not essential for the secretion process. However, BopE transcription and secretion were significantly increased in the bapB mutant, suggesting that BapB levels modulate BopE expression. In a BALB/c mouse model of acute melioidosis, the bapA, bapB and bapC mutants showed a minor reduction of in vivo fitness. Thus, this study defines BapA and BapC as novel TTSS3 effectors, BapB as a regulator of BopE production, and all three as necessary for full B. pseudomallei in vivo fitness.
Original languageEnglish
Article numbere0143916
Number of pages19
JournalPLoS ONE
Volume10
Issue number12
DOIs
Publication statusPublished - 2015

Cite this

Treerat, Puthayalai ; Alwis, Priyangi A ; D'Cruze, Tanya M ; Cullinane, Meabh ; Vadivelu, Jamunarani ; Devenish, Rodney J ; Prescott, Mark ; Adler, Ben ; Boyce, John D. / The Burkholderia pseudomallei proteins BapA and BapC are secreted TTSS3 effectors and BapB levels modulate expression of BopE. In: PLoS ONE. 2015 ; Vol. 10, No. 12.
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title = "The Burkholderia pseudomallei proteins BapA and BapC are secreted TTSS3 effectors and BapB levels modulate expression of BopE",
abstract = "Many Gram-negative pathogens use a type III secretion system (TTSS) for the injection of bacterial effector proteins into host cells. The injected effector proteins play direct roles in modulation of host cell pathways for bacterial benefit. Burkholderia pseudomallei, the causative agent of melioidosis, expresses three different TTSSs. One of these systems, the TTSS3, is essential for escape from host endosomes and therefore intracellular survival and replication. Here we have characterized three putative TTSS3 proteins; namely BapA, BapB and BapC. By employing a tetracysteine (TC)-FlAsH labelling technique to monitor the secretion of TC-tagged fusion proteins, BapA and BapC were shown to be secreted during in vitro growth in a TTSS3-dependant manner, suggesting a role as TTSS3 effectors. Furthermore, we constructed B. pseudomallei bapA, bapB and bapC mutants and used the well-characterized TTSS3 effector BopE as a marker of secretion to show that BapA, BapB and BapC are not essential for the secretion process. However, BopE transcription and secretion were significantly increased in the bapB mutant, suggesting that BapB levels modulate BopE expression. In a BALB/c mouse model of acute melioidosis, the bapA, bapB and bapC mutants showed a minor reduction of in vivo fitness. Thus, this study defines BapA and BapC as novel TTSS3 effectors, BapB as a regulator of BopE production, and all three as necessary for full B. pseudomallei in vivo fitness.",
author = "Puthayalai Treerat and Alwis, {Priyangi A} and D'Cruze, {Tanya M} and Meabh Cullinane and Jamunarani Vadivelu and Devenish, {Rodney J} and Mark Prescott and Ben Adler and Boyce, {John D}",
year = "2015",
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language = "English",
volume = "10",
journal = "PLoS ONE",
issn = "1932-6203",
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The Burkholderia pseudomallei proteins BapA and BapC are secreted TTSS3 effectors and BapB levels modulate expression of BopE. / Treerat, Puthayalai; Alwis, Priyangi A; D'Cruze, Tanya M; Cullinane, Meabh; Vadivelu, Jamunarani; Devenish, Rodney J; Prescott, Mark; Adler, Ben; Boyce, John D.

In: PLoS ONE, Vol. 10, No. 12, e0143916, 2015.

Research output: Contribution to journalArticleResearchpeer-review

TY - JOUR

T1 - The Burkholderia pseudomallei proteins BapA and BapC are secreted TTSS3 effectors and BapB levels modulate expression of BopE

AU - Treerat, Puthayalai

AU - Alwis, Priyangi A

AU - D'Cruze, Tanya M

AU - Cullinane, Meabh

AU - Vadivelu, Jamunarani

AU - Devenish, Rodney J

AU - Prescott, Mark

AU - Adler, Ben

AU - Boyce, John D

PY - 2015

Y1 - 2015

N2 - Many Gram-negative pathogens use a type III secretion system (TTSS) for the injection of bacterial effector proteins into host cells. The injected effector proteins play direct roles in modulation of host cell pathways for bacterial benefit. Burkholderia pseudomallei, the causative agent of melioidosis, expresses three different TTSSs. One of these systems, the TTSS3, is essential for escape from host endosomes and therefore intracellular survival and replication. Here we have characterized three putative TTSS3 proteins; namely BapA, BapB and BapC. By employing a tetracysteine (TC)-FlAsH labelling technique to monitor the secretion of TC-tagged fusion proteins, BapA and BapC were shown to be secreted during in vitro growth in a TTSS3-dependant manner, suggesting a role as TTSS3 effectors. Furthermore, we constructed B. pseudomallei bapA, bapB and bapC mutants and used the well-characterized TTSS3 effector BopE as a marker of secretion to show that BapA, BapB and BapC are not essential for the secretion process. However, BopE transcription and secretion were significantly increased in the bapB mutant, suggesting that BapB levels modulate BopE expression. In a BALB/c mouse model of acute melioidosis, the bapA, bapB and bapC mutants showed a minor reduction of in vivo fitness. Thus, this study defines BapA and BapC as novel TTSS3 effectors, BapB as a regulator of BopE production, and all three as necessary for full B. pseudomallei in vivo fitness.

AB - Many Gram-negative pathogens use a type III secretion system (TTSS) for the injection of bacterial effector proteins into host cells. The injected effector proteins play direct roles in modulation of host cell pathways for bacterial benefit. Burkholderia pseudomallei, the causative agent of melioidosis, expresses three different TTSSs. One of these systems, the TTSS3, is essential for escape from host endosomes and therefore intracellular survival and replication. Here we have characterized three putative TTSS3 proteins; namely BapA, BapB and BapC. By employing a tetracysteine (TC)-FlAsH labelling technique to monitor the secretion of TC-tagged fusion proteins, BapA and BapC were shown to be secreted during in vitro growth in a TTSS3-dependant manner, suggesting a role as TTSS3 effectors. Furthermore, we constructed B. pseudomallei bapA, bapB and bapC mutants and used the well-characterized TTSS3 effector BopE as a marker of secretion to show that BapA, BapB and BapC are not essential for the secretion process. However, BopE transcription and secretion were significantly increased in the bapB mutant, suggesting that BapB levels modulate BopE expression. In a BALB/c mouse model of acute melioidosis, the bapA, bapB and bapC mutants showed a minor reduction of in vivo fitness. Thus, this study defines BapA and BapC as novel TTSS3 effectors, BapB as a regulator of BopE production, and all three as necessary for full B. pseudomallei in vivo fitness.

UR - http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4666416/pdf/pone.0143916.pdf

U2 - 10.1371/journal.pone.0143916

DO - 10.1371/journal.pone.0143916

M3 - Article

VL - 10

JO - PLoS ONE

JF - PLoS ONE

SN - 1932-6203

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