Hage, H. | bioRxiv Science

bioRxiv2025

Transcriptomic and proteomic analysis of quiescent epimastigotes as a resource for investigating Trypanosoma cruzi persistence.

Chagas disease is caused by infection with the protozoan parasite Trypanosoma cruzi. Despite triggering a strong immune response, infections are typically life-long and can result in severe cardiac and/or digestive tract pathology. Current drugs have limited efficacy, and treatment failure is a common outcome. Eliminating a non-replicating T. cruzi sub-population that can persist after therapy has been a key challenge for the drug-development community. Here, we describe the transcriptome and proteome profiles of quiescent epimastigote forms of the parasite isolated from exponentially growing cultures on the basis of reduced turnover of transiently-induced red fluorescent protein. This quiescent sub-population was characterised by down-regulation of genes/proteins involved in translation, metabolism, mitochondrial function and DNA replication, and by up-regulation of proteins that promote exit from the cell-cycle in other organisms. These data represent a resource that can be exploited to dissect the mechanistic basis of quiescence and to refine the drug-development screening cascade.

microbiology↗

bioRxiv2021

Distribution of methionine sulfoxide reductases in fungi and conservation of the free-methionine-R-sulfoxide reductase in multicellular eukaryotes

Methionine, either as a free amino acid or included in proteins, can be oxidized into methionine sulfoxide (MetO), which exists as R and S diastereomers. Almost all characterized organisms possess thiol-oxidoreductases named methionine sulfoxide reductase (Msr) enzymes to reduce MetO back to Met. MsrA and MsrB reduce the S and R diastereomers of MetO, respectively, with strict stereospecificity and are found in almost all organisms. Another type of thiol-oxidoreductase, the free-methionine-R-sulfoxide reductase (fRMsr), identified so far in prokaryotes and a few unicellular eukaryotes, reduces the R MetO diastereomer of the free amino acid. Moreover, some bacteria possess molybdenum-containing enzymes that reduce MetO, either in the free or protein-bound forms. All these Msrs play important roles in the protection of organisms against oxidative stress. Fungi are heterotrophic eukaryotes that colonize all niches on Earth and play fundamental functions, in organic matter recycling, as symbionts, or as pathogens of numerous organisms. However, our knowledge on fungal Msrs is still limited. Here, we performed a survey of msr genes in almost 700 genomes across the fungal kingdom. We show that most fungi possess one gene coding for each type of methionine sulfoxide reductase: MsrA, MsrB, and fRMsr. However, several fungi living in anaerobic environments or as obligate intracellular parasites were devoid of msr genes. Sequence inspection and phylogenetic analyses allowed us to identify non-canonical sequences with potentially novel enzymatic properties. Finaly, we identified several ocurences of msr horizontal gene transfer from bacteria to fungi. HighlightsO_LIFree and protein-bound methionine can be oxidized into methionine sulfoxide (MetO). C_LIO_LIMethionine sulfoxide reductases (Msr) reduce MetO in most organisms. C_LIO_LISequence characterization and phylogenomics revealed strong conservation of Msr in fungi. C_LIO_LIfRMsr is widely conserved in unicellular and multicellular fungi. C_LIO_LISome msr genes were acquired from bacteria via horizontal gene transfers. C_LI

genomics↗