RNA Binding Proteins and Gene Expression Regulation in Trypanosoma cruzi

Abstract

The regulation of gene expression in trypanosomatids occurs mainly at the post-transcriptional level. In the case of Trypanosoma cruzi, the characterization of messenger ribonucleoprotein (mRNP) particles has allowed the identification of several classes of RNA binding proteins (RBPs), as well as non-canonical RBPs, associated with mRNA molecules. The protein composition of the mRNPs as well as the localization and functionality of the mRNAs depend on their associated proteins. mRNPs can also be organized into larger complexes forming RNA granules, which function as stress granules or P-bodies depending on the associated proteins. The fate of mRNAs in the cell, and consequently the genes expressed, depends on the set of proteins associated with the messenger molecule. These proteins allow the coordinated expression of mRNAs encoding proteins that are related in function, resulting in the formation of post-transcriptional operons. However, the puzzle posed by the combinatorial association of sets of RBPs with mRNAs and how this relates to the expressed genes remain to be elucidated. One important tool in this endeavor is the use of the CRISPR/CAS system to delete genes encoding RBPs, allowing the evaluation of their effect on the formation of mRNP complexes and associated mRNAs in the different compartments of the translation machinery. Accordingly, we recently established this methodology for T. cruzi and deleted the genes encoding RBPs containing zinc finger domains. In this manuscript, we will discuss the data obtained and the potential of the CRISPR/CAS methodology to unveil the role of RBPs in T. cruzi gene expression regulation.

EIF2αphosphorylation is regulated in intracellular amastigotes for the generation of infectiveTrypanosoma cruzitrypomastigote forms

“…The presence of specific RNA binding proteins could then direct the mRNAs for storage or degradation (Hentze, Castello, Schwarzl, & Preiss, 2018). In fact, several RNA binding proteins have been shown to control the fate of the different mRNAs in T. cruzi (Romagnoli, Holetz, Alves, & Goldenberg, 2020).…”

A Trypanosoma cruzi zinc finger protein that is implicated in the control of epimastigote-specific gene expression and metacyclogenesis

“…Experiments comparing the dynamics of association of TcZC3H12 with its target mRNAs and RNP granules during epimastigote growth and differentiation would provide further evidence for the role of this RBP. Although the mechanisms behind the formation of these cytoplasmic RNP granules as well as their function are not yet fully understood, several studies have showed that, both in T. brucei and T. cruzi, these granules are formed in response to nutritional stress and contain proteins homologous to those present in P bodies and stress granules from metazoan organisms (Cassola et al, 2007;Holetz et al, 2007Holetz et al, , 2010Romagnoli et al, 2020).…”

Identification of Novel Interspersed DNA Repetitive Elements in the Trypanosoma cruzi Genome Associated with the 3′UTRs of Surface Multigenic Families

“…Therefore, we propose that the 241 nt repeat could serve as a cis-regulatory element on mRNA, playing a role in the posttranscriptional regulation of surface proteins of T. cruzi . UTR segments are involved in gene expression regulation, regulating mRNA transcription to mRNA decay [ 38 ] and in the interaction of mRNA with other RNA molecules [ 39 ]. Diverse elements in the 3′ UTR region have been described to have cis-regulatory functions in gene expression [ 40 , 41 ] not only in later divergent eukaryotes but also in trypanosomatids [ 10 , 20 , 42 , 43 , 44 ].…”