Exploring the functionality and conservation of Alba proteins in Trypanosoma cruzi: A focus on biological diversity and RNA binding ability

Trypanosoma cruzi is the causative agent of Chagas disease, as well as a trypanosomatid parasite with a complex biological cycle that requires precise mechanisms for regulating gene expression. In Trypanosomatidae, gene regulation occurs mainly at the mRNA level through the recognition of cis elements by RNA-binding proteins (RBPs). Alba family members are ubiquitous DNA/RNA-binding proteins with representatives in trypanosomatid parasites functionally related to gene expression regulation. Although T. cruzi possesses two groups of Alba proteins (Alba1/2 and Alba30/40), their functional role remains poorly understood. Thus, herein, a characterization of T. cruzi Alba (TcAlba) proteins was undertaken. Physicochemical, structural, and phylogenetic analysis of TcAlba showed features compatible with RBPs, such as hydrophilicity, RBP domains/motifs, and evolutionary conservation of the Alba-domain, mainly regarding other trypanosomatid Alba. However, in silico RNA interaction analysis of T. cruzi Alba proteins showed that TcAlba30/40 proteins, but not TcAlba1/2, would directly interact with the assayed RNA molecules, suggesting that these two groups of TcAlba proteins have different targets. Given the marked differences existing between both T. cruzi Alba groups (TcAlba1/2 and TcAlba30/40), regarding sequence divergence, RNA binding potential, and life-cycle expression patterns, we suggest that they would be involved in different biological processes.