Bacterial siderophore suppresses host genetic disorders of hyperactivated Ras by limiting iron deficiency that...

Area of Science:

• Microbiology
• Genetics
• Developmental Biology

Background:

• Gut bacteria contribute to host health, but their role in mitigating genetic disorders is not fully understood.
• Ras gain-of-function mutations are highly detrimental, making mechanisms that counteract their effects crucial.
• Identifying bacterial factors that can suppress genetic defects is essential for therapeutic development.

Purpose of the Study:

• To screen for bacterial mutations that suppress genetic disorders.
• To elucidate the mechanism by which gut bacteria mitigate Ras gain-of-function defects.

Main Methods:

• Screened non-essential E. coli gene mutations for their ability to suppress let-60/ras(gf)-induced vulval defects in C. elegans.
• Investigated the role of bacterial siderophores and host iron availability in the suppression mechanism.
• Analyzed the downstream effects on host gene transcription and chromatin modification.

Main Results:

• Identified 151 E. coli mutants that suppress Ras gain-of-function-induced vulval defects.
• Discovered that mutations in iron acquisition genes elevate 2,3-dihydroxybenzoic acid, a siderophore that sequesters iron.
• Demonstrated that reduced host mitochondrial iron leads to LIN-65 nuclear accumulation, orchestrating the downregulation of lin-3/EGF transcription to repress Ras defects.

Conclusions:

• Gut bacteria can suppress host Ras gain-of-function defects through iron sequestration.
• This mechanism involves bacterial siderophores, host iron availability, and downstream transcriptional regulation.
• Modulating gut bacterial activity presents a potential strategy for managing genetic disorders.