Unraveling the role of YEATS domains in the cell cycle and DNA repair of Leishmania mexicana

• Grant number: 25/03898-5
• Support Opportunities: Scholarships in Brazil - Master
• Start date: May 01, 2025
• End date: August 31, 2026
• Field of knowledge: Biological Sciences - Parasitology - Protozoology of Parasites
• Principal Investigator: Nilmar Silvio Moretti
• Grantee: Miguel Antonio do Nascimento Garcia
• Host Institution: Escola Paulista de Medicina (EPM). Universidade Federal de São Paulo (UNIFESP). Campus São Paulo. São Paulo , SP, Brazil
• Associated research grant: 22/03075-0 - Unraveling the regulatory mechanisms of host-parasite interaction of Leishmania: focus on post-transcriptional and post-translational changes, AP.PNGP.PI

Abstract

Leishmania sp. is the etiological agent of leishmaniasis, a disease that affects both humans and animals present in various countries. The parasite has a heteroxenous life cycle, as it migrates between its invertebrate vector and a vertebrate host. In this process, it survives under distinct environmental conditions, necessitating changes in its cellular processes, such as gene expression and metabolism, for adaptation and survival. One of the mechanisms potentially involved in this molecular machinery of Leishmania is post-translational modifications (PTMs). Among these, crotonylation stands out as a modification previously identified in trypanosomatids, regulating various cellular processes and even contributing to the virulence of certain pathogens. The intricate regulation of crotonylation levels depends on crotonyltransferases, decrotonylases, and readers known as YEATS proteins. YEATS domains facilitate the binding of crotonylated lysines, enabling the recruitment of regulatory proteins and triggering downstream effects. Preliminary data from our group identified YEATS orthologs in L. mexicana and their subcellular localizations, as well as the roles these domains play in cellular functions during different stages of the parasite's life cycle, suggesting their impact on metacyclogenesis, amastigogenesis, and the multiplication of the procyclic stage in the parasites, using genetically modified strains to overexpress these domains. Other studies have related crotonylation in mammalian cells to DNA repair mechanisms, cell cycle regulation, and telomere maintenance. These processes may be crucial for the parasite's survival within the host cell. However, there are no studies on how crotonylation plays these roles in Leishmania. To expand the understanding of the impact of this modification on these cellular processes in Leishmania we will use different biochemistry and molecular biology techniques in this project to: (i) Evaluate the resistance of parasite YEATS overexpressors to genotoxic drugs (HU, MMS, UV, H2O2); (ii) Evaluate the expression and localization of ENL and Yaf9 under genotoxic drug pressure; (iii) Evaluate the chromatin structure of ENL and Yaf9 overexpressors by electron microscopy; (iv) Quantify crotonylation levels in the presence and absence of genotoxic drugs; (v) Evaluate the effect of ENL and Yaf9 overexpression on the cell cycle phases (G0, G1, S, M) of the parasite. This project is innovative and exploring the role of crotonylation in the cell cycle and DNA repair in Leishmania could have significant implications for the development of new therapeutic strategies. Inhibitors that modulate these modifications could potentially interrupt the cell cycle or compromise the parasite's ability to repair DNA damage, thus increasing the effectiveness of treatments against leishmaniasis. Thus, better understanding PTMs in Leishmania not only contributes to basic knowledge about the parasite, but also opens up new avenues for innovative therapeutic interventions.