# Development of a novel protein depletion method in Chlamydia

> **NIH NIH R21** · UNIVERSITY OF CALIFORNIA-IRVINE · 2024 · $196,250

## Abstract

Project Summary/Abstract
 More than 1.8 million cases of Chlamydia trachomatis infections are reported to the
CDC each year, making it the most commonly reported infectious disease in the country.
This pathogen is an obligate intracellular bacterium that can only reproduce in human
cells. As a result of this dependence on a host cell, Chlamydia has undergone reductive
evolution and has one of the smallest of bacterial genomes. Many of the remaining
genes, including Chlamydia-specific genes, are essential genes whose functions have
not been elucidated because of the limitations of current genetic methods. To study
chlamydial gene function, we are developing a novel protein depletion method that
exploits the ability of small RNAs (sRNAs) to downregulate expression of specific target
proteins. In proof-of-principle experiments, we have shown that we can inducibly
knockdown protein levels for two chlamydial proteins, IncA and IncG. In Aim 1, we will
knockdown additional C. trachomatis genes, including non-essential and essential
genes. In Aim 2, we will compare this sRNA knockdown method to another protein
depletion method, CRISPRi. We will compare the ability of each method to control the
level and timing of knockdown and will investigate whether they cause polar effects on
genes within the same operon. Successful completion of these studies will lead to an
innovative genetic approach for selectively depleting a Chlamydia protein. This new tool
for studying chlamydial gene function will have a sustained impact on the field.

## Key facts

- **NIH application ID:** 10782546
- **Project number:** 5R21AI171927-02
- **Recipient organization:** UNIVERSITY OF CALIFORNIA-IRVINE
- **Principal Investigator:** CHRISTINE SUETTERLIN
- **Activity code:** R21 (R01, R21, SBIR, etc.)
- **Funding institute:** NIH
- **Fiscal year:** 2024
- **Award amount:** $196,250
- **Award type:** 5
- **Project period:** 2023-02-08 → 2026-01-31

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/10782546

## Citation

> US National Institutes of Health, RePORTER application 10782546, Development of a novel protein depletion method in Chlamydia (5R21AI171927-02). Retrieved via AI Analytics 2026-06-12 from https://api.ai-analytics.org/grant/nih/10782546. Licensed CC0.

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