Understanding Promoter Elements Needed for Cell Type-Specific Gene Expression in Chlamydia trachomatis
Faculty Mentor Information
Dr. Nicole Grieshaber, University of Idaho; and Dr. Scott Grieshaber, University of Idaho
Presentation Date
7-15-2026
Abstract
Chlamydia trachomatis causes substantial disease in humans and relies on a unique specialized multi-cell-phenotype developmental cycle. This biphasic cycle progresses from infectious elementary bodies (EBs) to replicating reticulate bodies (RBs), with intermediate bodies (IBs) characterizing the transition between the EB and IB. Cell type-specific gene expression regulates the transition between these forms, although the corresponding promoter element characterization remains incomplete. We hypothesize that the global gene regulation patterns responsible for cell type-specific phenotypes are controlled by multiple DNA-binding proteins that may be working cooperatively. We have selected six highly regulated and verified cell type chlamydia promoters, 2 EB, 2 RB, and 2 IB, to investigate using engineered DNA-binding molecule-mediated chromatin immunoprecipitation (enChIP). This allows for DNA/protein interactions to be captured in an in vivo context, where native temporal competition between DNA binding proteins can occur. Short (-35) and extended (-100) versions of each of the two cell type promoters have been created through PCR amplification, infusion cloning, Escherichia coli propagation, and then transformation into C. trachomatis. COS-7 cells were infected with the transformed chlamydia, where they were analyzed by live cell imaging and confocal microscopy to assess the intensity differences in each promoter version using neongreen fluorescent proteins.
Understanding Promoter Elements Needed for Cell Type-Specific Gene Expression in Chlamydia trachomatis
Chlamydia trachomatis causes substantial disease in humans and relies on a unique specialized multi-cell-phenotype developmental cycle. This biphasic cycle progresses from infectious elementary bodies (EBs) to replicating reticulate bodies (RBs), with intermediate bodies (IBs) characterizing the transition between the EB and IB. Cell type-specific gene expression regulates the transition between these forms, although the corresponding promoter element characterization remains incomplete. We hypothesize that the global gene regulation patterns responsible for cell type-specific phenotypes are controlled by multiple DNA-binding proteins that may be working cooperatively. We have selected six highly regulated and verified cell type chlamydia promoters, 2 EB, 2 RB, and 2 IB, to investigate using engineered DNA-binding molecule-mediated chromatin immunoprecipitation (enChIP). This allows for DNA/protein interactions to be captured in an in vivo context, where native temporal competition between DNA binding proteins can occur. Short (-35) and extended (-100) versions of each of the two cell type promoters have been created through PCR amplification, infusion cloning, Escherichia coli propagation, and then transformation into C. trachomatis. COS-7 cells were infected with the transformed chlamydia, where they were analyzed by live cell imaging and confocal microscopy to assess the intensity differences in each promoter version using neongreen fluorescent proteins.