Functional Characterization of NFS, ISD11, and MTU1 Proteins: involvement in Mitochondrial Biology in Trypanosoma cruzi.

• Grant number: 23/16035-0
• Support Opportunities: Scholarships in Brazil - Doctorate (Direct)
• Start date: March 01, 2024
• End date: April 30, 2027
• Field of knowledge: Biological Sciences - Genetics - Molecular Genetics and Genetics of Microorganisms
• Principal Investigator: Ariel Mariano Silber
• Grantee: Marilene Souza Braga
• 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
• Associated scholarship(s): 24/22253-2 - Analysis of the impact of knocking out Nfs and Mtu1 on thiolation of tRNAs in Trypanosoma cruzi, BE.EP.DD

Abstract

Trypanosoma cruzi, which causes Chagas disease, affects around 7 million people worldwide. This has unique characteristics like a single branched mitochondria housing the mitochondrial genome (kDNA). For the translation of genes encoded by kDNA to occur, it is necessary to import all transport RNAs (tRNAs) from the cytosol. tRNAs are post-transcriptionally modified and these modifications perform different functions such as stability and regulation of gene expression. Among the modifications identified so far, thiolation was found in positions 33 and 34 of tRNAs, with uridine thiolation in position 33 (sU33) identified only in trypanosomatids. sU33 thiolation negatively modulates tRNATrp editing in Trypanosoma brucei mitochondria, which impacts mitochondrial gene expression. The protein complex responsible for this modification is formed by a cysteine desulfurase (NFS; EC.:2.8.1.7), its accessory protein (ISD11) and a tRNA-specific 2-thiouridylase (MTU1; E.C.:2.8.1.14), using the amino acid cysteine as a thiol group donor. In addition to thiolation, the NFS and ISD11 proteins are involved in the synthesis of Fe-S complexes, crucial to electron transfer and protein biogenesis. The T. cruzi genome encodes putative orthologs of these proteins, but their involvement in the mitochondrial biology of this parasite has not yet been investigated. Therefore, the present project aims to investigate the impact of these enzymes on the biology of T. cruzi, through: i. phenotyping throughout the parasite's life cycle of knockout lines already produced for the genes of interest, ii. determination of the subcellular localization and functional partners of the proteins of interest; and iii. characterization of the enzymatic activity of the NFS and MTU1 proteins.