# Dopamine Is a Key Regulatory Molecule for Escherichia coli and May Serve as a Xenosiderophore

## TL;DR

Dopamine boosts Escherichia coli growth and activity by acting as a signaling molecule and xenosiderophore, influencing iron uptake and other bacterial processes.

## Contribution

This study reveals dopamine's dual role as a xenosiderophore and signaling molecule in E. coli, with multi-omics evidence of its regulatory effects.

## Key findings

- Dopamine treatment increased E. coli's growth biomass, biofilm formation, and motility by significant percentages.
- Transcriptome analysis showed dopamine upregulates iron uptake, biofilm, and virulence genes in E. coli.
- HPLC-MS and IRMS confirmed dopamine uptake by E. coli, indicating specific transport pathways.

## Abstract

Previous studies have demonstrated that catecholamines, including epinephrine (Epi), norepinephrine (NE), and dopamine (DA), function both as xenosiderophores for bacteria possessing dedicated transport channels and as potential quorum-sensing signaling molecules or regulatory factors. However, current research on the interactions between dopamine and bacteria remains relatively limited. In this study, treatment of Escherichia coli (E. coli) ATCC 11303 with a specific concentration of dopamine resulted in a 33.63% increase in the maximum growth biomass, a 47.32% enhancement in biofilm formation, a 24.60% increase in protease activity, a 68.81% improvement in swimming motility, and increases of 33.77% and 47.67% in chemotaxis and swarming motility, respectively. Transcriptome analysis revealed that dopamine promoted the expression of numerous iron uptake-related genes, while biofilm formation-related genes and virulence genes were concomitantly upregulated. High-performance liquid chromatography–mass spectrometry (HPLC-MS) and isotope ratio mass spectrometry (IRMS) analyses confirmed that E. coli ATCC 11303 can uptake dopamine, suggesting the existence of specific transport pathways. Multi-omics analysis revealed significant regulatory effects on metal ion transport, amino acid metabolism, purine metabolism, environmental adaptation, quorum sensing, two-component systems, and xylene degradation pathways. Dopamine may act as both a xenosiderophore and a signaling molecule, thereby modulating multiple critical physiological and biochemical processes and promoting bacterial growth. These findings provide valuable insights into the development of novel exogenous xenosiderophores and signaling modulators, advancing our understanding of microbial interactions with their host environment and contributing to the field of microbial endocrinology.