PDIM/PGL-deficient Mycobacterium marinum shows disrupted protein secretion measured with bottom-up label-free...

Area of Science:

• Microbiology
• Proteomics
• Lipid biochemistry

Background:

• Mycobacterium marinum is an important model organism for studying mycobacterial pathogenesis.
• Phthiocerol dimycocerosate and phenolic glycolipid (PDIM/PGL) are key virulence lipids in many mycobacteria.
• The precise roles of PDIM/PGL in M. marinum virulence are not fully understood.

Purpose of the Study:

• To investigate the chemical and functional consequences of PDIM/PGL deficiency in M. marinum.
• To identify protein expression changes associated with PDIM/PGL absence using quantitative proteomics.
• To assess the impact of PDIM/PGL deficiency on ESAT-6 System-1 export and overall virulence.

Main Methods:

• Quantitative proteomics was employed to analyze protein expression profiles.
• A M. marinum strain deficient in PDIM/PGL synthesis was compared to a wild-type strain.
• Protein dysregulation, ESAT-6 System-1 export, and virulence were measured.

Main Results:

• A significant dysregulation of 1,006 proteins was observed in the PDIM/PGL-deficient strain.
• ESAT-6 System-1 export and virulence were significantly altered.
• PDIM/PGL deficiency specifically decreased the export of proteins with low isoelectric points.

Conclusions:

• PDIM/PGL lipids play a crucial role in regulating protein export and virulence in M. marinum.
• The absence of PDIM/PGL leads to widespread proteomic changes and affects specific protein secretion pathways.
• Understanding these lipid-protein interactions is vital for developing novel anti-mycobacterial strategies.