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Updated: Jun 6, 2026
Using Fluorescent Proteins to Visualize and Quantitate Chlamydia Vacuole Growth Dynamics in Living Cells
Published on: October 13, 2015
The trans-Golgi SNARE syntaxin 6 is recruited to the chlamydial inclusion membrane
Elizabeth R Moore1, David J Mead1, Cheryl A Dooley1
1Host-Parasite Interactions Section, Laboratory of Intracellular Parasites, National Institute of Allergy and Infectious Diseases, Rocky Mountain Laboratories, 903 South 4th Street, Hamilton, MT 59840, USA.
Abstract:
Chlamydia trachomatis is an obligate intracellular pathogen that replicates within a parasitophorous vacuole termed an inclusion. The chlamydial inclusion is isolated from the endocytic pathway but fusogenic with Golgi-derived exocytic vesicles containing sphingomyelin and cholesterol. Sphingolipids are incorporated into the chlamydial cell wall and are considered essential for chlamydial development and viability. The mechanisms by which chlamydiae obtain eukaryotic lipids are poorly understood but require chlamydial protein synthesis and presumably modification of the inclusion membrane to initiate this interaction. A polarized cell model of chlamydial infection has demonstrated that chlamydiae preferentially intercept basolaterally directed, sphingomyelin-containing exocytic vesicles. Here we examine the localization and potential function of trans-Golgi and/or basolaterally associated soluble N-ethylmaleimide-sensitive factor attachment protein receptor (SNARE) proteins in chlamydia-infected cells. The trans-Golgi SNARE protein syntaxin 6 is recruited to the chlamydial inclusion in a manner that requires chlamydial protein synthesis and is conserved among all chlamydial species examined. The localization of syntaxin 6 to the chlamydial inclusion requires a tyrosine motif or plasma membrane retrieval signal (YGRL). Thus in addition to expression of at least two inclusion membrane proteins that contain SNARE-like motifs, chlamydiae also actively recruit eukaryotic SNARE-family proteins.
Insights
Chlamydia trachomatis actively recruits host cell proteins, specifically syntaxin 6, to its inclusion membrane. This interaction, crucial for pathogen development, requires bacterial protein synthesis and specific signaling motifs.
Area of Science:
- Microbiology
- Cell Biology
- Pathogen-Host Interactions
Background:
- Chlamydia trachomatis is an obligate intracellular bacterium forming a unique inclusion vacuole.
- Chlamydial development and viability depend on incorporating host sphingolipids into its cell wall.
- Mechanisms of eukaryotic lipid acquisition by Chlamydia are not fully understood.
Purpose of the Study:
- To investigate the role of trans-Golgi and basolaterally associated SNARE proteins in Chlamydia-infected cells.
- To determine if Chlamydia actively recruits eukaryotic SNARE proteins to the inclusion membrane.
Main Methods:
- Utilized a polarized cell model of Chlamydia infection.
- Examined the localization of trans-Golgi SNARE protein syntaxin 6 in infected cells.
- Investigated the requirement of chlamydial protein synthesis and specific signaling motifs for syntaxin 6 recruitment.
Main Results:
- Syntaxin 6, a trans-Golgi SNARE, is recruited to the chlamydial inclusion.
- Syntaxin 6 recruitment is dependent on chlamydial protein synthesis and conserved across Chlamydia species.
- A tyrosine motif (YGRL) is essential for syntaxin 6 localization to the inclusion.
Conclusions:
- Chlamydia actively recruits eukaryotic SNARE proteins, like syntaxin 6, to its inclusion membrane.
- This recruitment process involves chlamydial protein synthesis and specific targeting signals.
- Chlamydiae employ sophisticated strategies to hijack host cell machinery for lipid acquisition and survival.
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