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Updated: Jul 12, 2026

In-vitro Reconstitution of Bacterial Ubiquitination and VCP/p97-mediated Elimination
Published on: January 2, 2026
Lysosomal ubiquitin and the demise of Mycobacterium tuberculosis
Georgiana E Purdy1, David G Russell
1Department of Microbiology and Immunology, College of Veterinary Medicine, Cornell University, Ithaca, NY 14853, USA. gep9@cornell.edu
Abstract:
The antimicrobial activity of macrophages is mediated by both oxidative and non-oxidative mechanisms. Oxidative mechanisms include the action of reactive oxygen and nitrogen intermediates on bacteria. Non-oxidative mechanisms include the maturation of the phagosome into an acidified, hydrolytically active compartment as well as the action of antimicrobial peptides. Mycobacterium tuberculosis parasitizes the host macrophage by arresting the normal maturation of its phagosome and resides in a compartment that fails to fuse with lysosomes. When bacteria are unable to regulate phagosome maturation, such as in activated macrophages, they are delivered to lysosomal compartments, where they are killed. Recent data indicate that the antimycobacterial mechanism of the lysosome is due in part to the action of ubiquitin-derived peptides.
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