A mycobacterial effector promotes ferroptosis-dependent pathogenicity and dissemination

Area of Science:

• Cell Biology
• Microbiology
• Immunology

Background:

• Ferroptosis, a form of programmed cell death driven by lipid peroxidation and iron, is implicated in various diseases.
• Pathogens can manipulate host ferroptosis for their survival and spread, but mechanisms are often unclear.

Purpose of the Study:

• To elucidate the molecular mechanisms by which Mycobacterium tuberculosis (Mtb) utilizes host cell processes to promote its pathogenicity.
• To identify specific pathogen factors that induce ferroptosis and understand their role in tuberculosis (TB) pathogenesis.

Main Methods:

• Investigated the role of Mtb's secreted effector, protein tyrosine phosphatase A (PtpA), in inducing host cell death.
• Utilized techniques to track PtpA's cellular localization and interactions within host cells, including nuclear entry.
• Analyzed the impact of PtpA on host epigenetic modifications, specifically histone methylation, and gene expression.

Main Results:

• Identified PtpA as a key Mtb virulence factor that triggers ferroptosis in host cells.
• Demonstrated that PtpA enters the host cell nucleus via interaction with RanGDP at its Cys11 site.
• Showed that nuclear PtpA enhances histone H3R2me2a methylation by targeting PRMT6, leading to suppressed GPX4 expression and ferroptosis induction.

Conclusions:

• Mycobacterium tuberculosis PtpA promotes pathogenicity and dissemination by inducing host cell ferroptosis.
• The mechanism involves PtpA's nuclear translocation and subsequent epigenetic modification of host genes regulating ferroptosis.
• Targeting the PtpA-PRMT6 interaction presents a potential therapeutic strategy for tuberculosis by inhibiting GPX4-dependent ferroptosis.