title: Novel protein acetyltransferase, Rv2170, modulates carbon and energy metabolism in Mycobacterium tuberculosis.
abstract: Recent data indicate that the metabolism of Mycobacterium tuberculosis (Mtb) inside its host cell is heavily dependent on cholesterol and fatty acids. Mtb exhibits a unique capacity to co-metabolize different carbon sources and the products from these substrates are compartmentalized metabolically. Isocitrate lies at one of the key nodes of carbon metabolism and can feed into either the glyoxylate shunt (via isocitrate lyase) or the TCA cycle (via isocitrate dehydrogenase (ICDH) activity) and we sought to better understand the regulation at this junction. An isocitrate lyase-deficient mutant of Mtb (Δicl1) exhibited a delayed growth phenotype in stearic acid (C18 fatty acid) media and we isolated rescue mutants that had lost this growth delay. We found that mutations in the gene rv2170 promoted Mtb replication under these conditions and rescued the growth delay in a Δicl1 background. The Mtb Rv2170 protein shows lysine acetyltransferase activity, which is capable of post-translationally modifying lysine residues of the ICDH protein leading to a reduction in its enzymatic activity. Our data show that contrary to most bacteria that regulate ICDH activity through phosphorylation, Mtb is capable of regulating ICDH activity by acetylation. This mechanism of regulation is similar to that utilized for mammalian mitochondrial ICDH.
authors.affiliation: Department of Microbiology and Immunology, College of Veterinary Medicine, Cornell University, Ithaca, NY, 14853, United States.|Department of Microbiology and Immunology, Harvard Medical School, Boston, Massachusetts, 02115, United States.
authors.forename: Wonsik
authors.initials: W
authors.lastname: Lee
authors.affiliation: Department of Microbiology and Immunology, College of Veterinary Medicine, Cornell University, Ithaca, NY, 14853, United States.
authors.forename: Brian C
authors.initials: BC
authors.lastname: VanderVen
authors.affiliation: Department of Microbiology and Immunology, Harvard Medical School, Boston, Massachusetts, 02115, United States.
authors.forename: Suzanne
authors.initials: S
authors.lastname: Walker
authors.affiliation: Department of Microbiology and Immunology, College of Veterinary Medicine, Cornell University, Ithaca, NY, 14853, United States. dgr8@cornell.edu.
authors.forename: David G
authors.initials: DG
authors.lastname: Russell
mesh_terms: D000107:Acetylation; D001426:Bacterial Proteins / Q000378:metabolism; D002244:Carbon / Q000378:metabolism*; D004261:DNA Replication; D004734:Energy Metabolism; D007522:Isocitrate Lyase / Q000235:genetics*; D008239:Lysine / Q000737:chemistry; D000070837:Lysine Acetyltransferases / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism; D009154:Mutation; D009169:Mycobacterium tuberculosis / Q000201:enzymology / Q000235:genetics / Q000254:growth & development*; D010766:Phosphorylation; D013229:Stearic Acids / Q000378:metabolism
chemical_list: D001426:Bacterial Proteins; D013229:Stearic Acids; C031183:stearic acid; D002244:Carbon; D000070837:Lysine Acetyltransferases; D007522:Isocitrate Lyase; D008239:Lysine