Evaluation of the Succinyl-CoA Synthetase/Acetate:Succinate CoA Transferase (SCS/ASCT) cycle in the biology of Trypanosoma cruzi: contribution of amino acids in the production of mitochondrial ATP at the substrate level, bioenergetics and lipid synthesis

• Grant number: 22/16078-8
• Support Opportunities: Scholarships in Brazil - Post-Doctoral
• Effective date (Start): December 01, 2023
• Effective date (End): November 30, 2025
• Field of knowledge: Biological Sciences - Parasitology - Protozoology of Parasites
• Principal Investigator: Ariel Mariano Silber
• Grantee: Mayke Bezerra Alencar
• Host Institution: Instituto de Ciências Biomédicas (ICB). Universidade de São Paulo (USP). São Paulo , SP, Brazil
• Associated research grant: 21/12938-0 - Amino acid metabolism in Trypanosoma cruzi: a toolbox to survive in hostile environments, AP.TEM

Abstract

Several studies, including from our research group, have described the importance of amino acids in the biology of trypanosomatids, focusing on the group known as TriTryps, which includes Trypanosoma cruzi, Trypanosoma brucei, and pathogenic species of the genus Leishmania. TriTryps use amino acids for several functions other than protein synthesis such as cell differentiation, invasion of mammalian host cells (in species with an intracellular cycle), establishment of infection and resistance to different types of stress to which the parasite is naturally exposed. subjected throughout its biological cycle, such as osmotic, thermal, oxidative and nutritional stress. This project aims to characterize in detail the enzymatic steps that constitute the cycle Acetate:Succinate CoA Transferase (ASCT: EC 2.8.3.18) and Succinyl-CoA Synthetase (SCS: EC 6.2.1.5) (ASCT/SCS) in T. cruzi , which interconnect amino acid metabolism with mitochondrial metabolism and lipid synthesis. For this, we propose: (1) to biochemically characterize the product of putative genes for these enzymes; (2) determine which amino acids participate in donating carbons in this cycle: i) evaluate the synthesis of ATP and intramitochondrial acetate, respiratory burst and mitochondrial inner membrane potential, ii) differentiation, iii) maintenance of cell invasion, iv) resistance to oxidative stress, thermal, nutritional and acidic, v) modulation of the cell cycle, autophagy and cell death under metabolic stress; (3) Develop knockout (or hemi-knockout) strains using CRISPR/Cas9 for the enzymes of the ASCT/SCS cycle in order to evaluate their possible effects on the biology of T. cruzi. Evaluate by metabolomics the effect of gene manipulation or treatment with inhibitors on the metabolic profile of cells and (6) Evaluate the impact of amino acid metabolism on fatty acid and lipid biosynthesis pathways from the ASCT/SCS cycle. (AU)