The chlamydial periplasmic stress response serine protease cHtrA is secreted into host cell cytosol

Xiang Wu, Lei Lei, Siqi Gong, Ding Chen, Rhonda Flores, Guangming Zhong

Research output: Contribution to journalArticlepeer-review

51 Scopus citations

Abstract

Background: The periplasmic High Temperature Requirement protein A (HtrA) plays important roles in bacterial protein folding and stress responses. However, the role of chlamydial HtrA (cHtrA) in chlamydial pathogenesis is not clear. Results: The cHtrA was detected both inside and outside the chlamydial inclusions. The detection was specific since both polyclonal and monoclonal anti-cHtrA antibodies revealed similar intracellular labeling patterns that were only removed by absorption with cHtrA but not control fusion proteins. In a Western blot assay, the anti-cHtrA antibodies detected the endogenous cHtrA in Chlamydia-infected cells without cross-reacting with any other chlamydial or host cell antigens. Fractionation of the infected cells revealed cHtrA in the host cell cytosol fraction. The periplasmic cHtrA protein appeared to be actively secreted into host cell cytosol since no other chlamydial periplasmic proteins were detected in the host cell cytoplasm. Most chlamydial species secreted cHtrA into host cell cytosol and the secretion was not inhibitable by a type III secretion inhibitor. Conclusion: Since it is hypothesized that chlamydial organisms possess a proteolysis strategy to manipulate host cell signaling pathways, secretion of the serine protease cHtrA into host cell cytosol suggests that the periplasmic cHtrA may also play an important role in chlamydial interactions with host cells.

Original languageEnglish (US)
Article number87
JournalBMC Microbiology
Volume11
DOIs
StatePublished - 2011

Keywords

  • Chlamydia trachomatis
  • cHtrA
  • secreted protein
  • serine protease

ASJC Scopus subject areas

  • Microbiology (medical)
  • Microbiology

Fingerprint

Dive into the research topics of 'The chlamydial periplasmic stress response serine protease cHtrA is secreted into host cell cytosol'. Together they form a unique fingerprint.

Cite this