|Trehalose-6-Phosphate-Mediated Toxicity Determines Essentiality of OtsB2 in Mycobacterium tuberculosis In Vitro and in Mice.
|Year of Publication
|Korte J, Alber M, Trujillo CM, Syson K, Koliwer-Brandl H, Deenen R, Köhrer K, DeJesus MA, Hartman T, Jacobs WR, Bornemann S, Ioerger TR, Ehrt S, Kalscheuer R
|Animals, Bacterial Proteins, Chromatography, Thin Layer, Disease Models, Animal, Female, Gene Expression Profiling, Gene Knockdown Techniques, Glucosyltransferases, In Vitro Techniques, Mice, Mice, Inbred C57BL, Mycobacterium tuberculosis, Nuclear Magnetic Resonance, Biomolecular, Phosphoric Monoester Hydrolases, Real-Time Polymerase Chain Reaction, Sugar Phosphates, Trehalose, Tuberculosis
Trehalose biosynthesis is considered an attractive target for the development of antimicrobials against fungal, helminthic and bacterial pathogens including Mycobacterium tuberculosis. The most common biosynthetic route involves trehalose-6-phosphate (T6P) synthase OtsA and T6P phosphatase OtsB that generate trehalose from ADP/UDP-glucose and glucose-6-phosphate. In order to assess the drug target potential of T6P phosphatase, we generated a conditional mutant of M. tuberculosis allowing the regulated gene silencing of the T6P phosphatase gene otsB2. We found that otsB2 is essential for growth of M. tuberculosis in vitro as well as for the acute infection phase in mice following aerosol infection. By contrast, otsB2 is not essential for the chronic infection phase in mice, highlighting the substantial remodelling of trehalose metabolism during infection by M. tuberculosis. Blocking OtsB2 resulted in the accumulation of its substrate T6P, which appears to be toxic, leading to the self-poisoning of cells. Accordingly, blocking T6P production in a ΔotsA mutant abrogated otsB2 essentiality. T6P accumulation elicited a global upregulation of more than 800 genes, which might result from an increase in RNA stability implied by the enhanced neutralization of toxins exhibiting ribonuclease activity. Surprisingly, overlap with the stress response caused by the accumulation of another toxic sugar phosphate molecule, maltose-1-phosphate, was minimal. A genome-wide screen for synthetic lethal interactions with otsA identified numerous genes, revealing additional potential drug targets synergistic with OtsB2 suitable for combination therapies that would minimize the emergence of resistance to OtsB2 inhibitors.
|PubMed Central ID
|R01 AI026170 / AI / NIAID NIH HHS / United States
R37 AI026170 / AI / NIAID NIH HHS / United States
Submitted by jom4013 on December 3, 2020 - 2:05pm