Characterization and biological role of the Glutamine-dependent Asparagine Synthase of Trypanosoma cruzi

• Grant number: 23/06791-1
• Support Opportunities: Scholarships in Brazil - Doctorate (Direct)
• Start date: July 01, 2023
• End date: June 30, 2027
• Field of knowledge: Biological Sciences - Parasitology - Protozoology of Parasites
• Principal Investigator: Ariel Mariano Silber
• Grantee: Vitória Jordana 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

Aspartate, in the presence of carbamoyl phosphate, can be converted by the enzyme Aspartate carbamoyltransferase (AspCT, EC 2.1.3.2) into Carbamoyl-L-Aspartate, a precursor for the de novo biosynthesis of pyrimidines. In turn, carbamoyl phosphate, in T. cruzi would initially be supplied by Carbamoyl-Phosphate Synthetase (CPS) II, (EC 6.3.5.5) from Gln. This same enzyme also reconverts Glutamine into Glutamate, so that these two steps together link both amino acids with the synthesis of nucleotide precursors. Since both amino acids are involved in the supply of intermediate of the TCA cycle, it is natural to hypothesize that both enzymes are relevant, on the one hand for the availability of pyrimidines for functions such as transcription and replication, and on the other hand for mitochondrial functionality. This proposal aims to understand the role of enzymes through their biochemical characterization, as well as the phenotypes associated with their deletion or modification via gene editing technologies such as CRISPR/Cas9. (AU)