pubmed.ncbi.nlm.nih.gov

Acidic pH is required for the functional assembly of the type III secretion system encoded by Salmonella pathogenicity island 2 - PubMed

️Wed Jan 01 2003

Acidic pH is required for the functional assembly of the type III secretion system encoded by Salmonella pathogenicity island 2

Catherine Rappl et al. FEMS Microbiol Lett. 2003.

Abstract

Salmonella enterica employs two type III secretion systems (T3SS) for interactions with host cells during pathogenesis. The T3SS encoded by Salmonella pathogenicity island 2 (SPI2) is required for the intracellular replication of Salmonella and the survival inside phagocytes. During growth in vitro, acidic pH is a signal that promotes secretion of proteins by this T3SS. We analyzed protein levels and subcellular localization of various T3SS subunits under in vitro conditions at acidic or neutral pH, inducing or ablating secretion, respectively. Growth at acidic pH resulted in higher levels of SsaC, a protein forming the outer membrane secretin, without increasing expression of the operon containing ssaC. Acidic pH also induced oligomerization of SsaC subunits, a prerequisite for a functional secretin pore. It has previously been described that environmental stimuli resembling the intraphagosomal habitat of Salmonella control the expression of SPI2 genes. Here we propose that such stimuli also modulate the assembly of a functional T3SS that is capable of translocation of effector proteins into the host cell.

PubMed Disclaimer

Cited by

Models of intestinal infection by Salmonella enterica: introduction of a new neonate mouse model.
Schulte M, Hensel M. Schulte M, et al. F1000Res. 2016 Jun 24;5:F1000 Faculty Rev-1498. doi: 10.12688/f1000research.8468.1. eCollection 2016. F1000Res. 2016. PMID: 27408697 Free PMC article. Review.
Salmonella enterica response regulator SsrB relieves H-NS silencing by displacing H-NS bound in polymerization mode and directly activates transcription.
Walthers D, Li Y, Liu Y, Anand G, Yan J, Kenney LJ. Walthers D, et al. J Biol Chem. 2011 Jan 21;286(3):1895-902. doi: 10.1074/jbc.M110.164962. Epub 2010 Nov 8. J Biol Chem. 2011. PMID: 21059643 Free PMC article.
A Novel Approach against Salmonella: A Review of Polymeric Nanoparticle Vaccines for Broilers and Layers.
Acevedo-Villanueva KY, Akerele GO, Al Hakeem WG, Renu S, Shanmugasundaram R, Selvaraj RK. Acevedo-Villanueva KY, et al. Vaccines (Basel). 2021 Sep 18;9(9):1041. doi: 10.3390/vaccines9091041. Vaccines (Basel). 2021. PMID: 34579278 Free PMC article. Review.
Type III secretion systems: the bacterial flagellum and the injectisome.
Diepold A, Armitage JP. Diepold A, et al. Philos Trans R Soc Lond B Biol Sci. 2015 Oct 5;370(1679):20150020. doi: 10.1098/rstb.2015.0020. Philos Trans R Soc Lond B Biol Sci. 2015. PMID: 26370933 Free PMC article. Review.
Dynamic relocalization of cytosolic type III secretion system components prevents premature protein secretion at low external pH.
Wimmi S, Balinovic A, Jeckel H, Selinger L, Lampaki D, Eisemann E, Meuskens I, Linke D, Drescher K, Endesfelder U, Diepold A. Wimmi S, et al. Nat Commun. 2021 Mar 12;12(1):1625. doi: 10.1038/s41467-021-21863-4. Nat Commun. 2021. PMID: 33712575 Free PMC article.

Acidic pH is required for the functional assembly of the type III secretion system encoded by Salmonella pathogenicity island 2 - PubMed