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Lipid droplet-associated proteins are involved in the biosynthesis and hydrolysis of triacylglycerol in Mycobacterium bovis bacillus Calmette-Guerin.
- Source :
-
The Journal of biological chemistry [J Biol Chem] 2010 Jul 09; Vol. 285 (28), pp. 21662-70. Date of Electronic Publication: 2010 May 06. - Publication Year :
- 2010
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Abstract
- Mycobacteria store triacylglycerols (TGs) in the form of intracellular lipid droplets (LDs) during hypoxia-induced nonreplicating persistence. These bacteria are phenotypically drug-resistant and therefore are believed to be the cause for prolonged tuberculosis treatment. LDs are also associated with bacilli in tuberculosis patient sputum and hypervirulent strains. Although proteins bound to LDs are well characterized in eukaryotes, the identities and functions of such proteins have not been described in mycobacteria. Here, we have identified five proteins: Tgs1 (BCG3153c), Tgs2 (BCG3794c), BCG1169c, BCG1489c, and BCG1721, which are exclusively associated with LDs purified from hypoxic nonreplicating Mycobacterium bovis bacillus Calmette-Guérin (BCG). Disruption of genes tgs1, tgs2, BCG1169c, and BCG1489c in M. bovis BCG revealed that they are indeed involved in TG metabolism. We also characterized BCG1721, an essential bi-functional enzyme capable of promoting buildup and hydrolysis of TGs, depending on the metabolic state. Nonreplicating mycobacteria overexpressing a BCG1721 construct with an inactive lipase domain displayed a phenotype of attenuated TG breakdown and regrowth upon resuscitation. In addition, by heterologous expression in baker's yeast, these mycobacterial proteins also co-localized with LDs and complemented a lipase-deficient yeast strain, indicating that neutral lipid deposition and homeostasis in eukaryotic and prokaryotic microorganisms are functionally related. The demonstrated functional role of BCG1721 to support growth upon resuscitation makes this novel LD-associated factor a potential new target for therapeutic intervention.
- Subjects :
- Genetic Complementation Test
Humans
Hydrolysis
Hypoxia
Mass Spectrometry methods
Models, Biological
Mutagenesis, Site-Directed
Mutation
Mycobacterium metabolism
Peptides chemistry
Protein Structure, Tertiary
Trypsin chemistry
BCG Vaccine chemistry
Lipids chemistry
Mycobacterium bovis metabolism
Subjects
Details
- Language :
- English
- ISSN :
- 1083-351X
- Volume :
- 285
- Issue :
- 28
- Database :
- MEDLINE
- Journal :
- The Journal of biological chemistry
- Publication Type :
- Academic Journal
- Accession number :
- 20452973
- Full Text :
- https://doi.org/10.1074/jbc.M110.135731