# Functional exploration of a deep Mycobacterium tuberculosis phosphoproteome

> **NIH NIH R01** · SEATTLE CHILDREN'S HOSPITAL · 2024 · $614,035

## Abstract

ABSTRACT
Phosphosignaling provides the major conduit for bacterial adaptation. The two component systems (TCSs)
have long been viewed as the canonical phosphosignaling systems in bacteria, but increasingly, O-
phosphorylation mediated by Ser/Thr kinases is recognized as a relevant bacterial phosphosignaling
mechanism as well. We now show that in fact, Mycobacterium tuberculosis (Mtb) has an expansive,
distributed, and cooperative O-phosphorylation system of a size and complexity that is typically only associated
with eukaryotes. By using a comprehensive STPK loss- and gain-of-function mutant panel and quantitative
mass spectrometry, we show that >70% of Mtb proteins are phosphorylated on Ser/Thr/Tyr, identify thousands
of individual Ser/Thr kinase substrates, and show that the Ser/Thr kinases collectively control the expression of
~30% of Mtb genes. Here, we will test a new and extensive regulatory connection between the Ser/Thr kinases
and the His kinases of the TCSs and test the role of O-phosphorylation on the regulation of transcription
factors. As a result of our exhaustive analysis of Mtb phosphorylation, we also obtained the first evidence of
Arg phosphorylation in Mtb- the first bacterial Arg phosphoproteome outside of gram-positive bacteria. We will
identify the relevant phosphoenzymes and test the idea that pArg functions as a degradation tag for ClpP-
mediated proteolysis.

## Key facts

- **NIH application ID:** 10775829
- **Project number:** 5R01AI170914-02
- **Recipient organization:** SEATTLE CHILDREN'S HOSPITAL
- **Principal Investigator:** Christoph Grundner
- **Activity code:** R01 (R01, R21, SBIR, etc.)
- **Funding institute:** NIH
- **Fiscal year:** 2024
- **Award amount:** $614,035
- **Award type:** 5
- **Project period:** 2023-02-03 → 2028-01-31

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/10775829

## Citation

> US National Institutes of Health, RePORTER application 10775829, Functional exploration of a deep Mycobacterium tuberculosis phosphoproteome (5R01AI170914-02). Retrieved via AI Analytics 2026-05-25 from https://api.ai-analytics.org/grant/nih/10775829. Licensed CC0.

---

*[NIH grants dataset](/datasets/nih-grants) · CC0 1.0*