Exploring nuclear plasticity and chromatin structure in Leishmania

• Grant number: 25/20402-3
• Support Opportunities: Scholarships in Brazil - Doctorate
• Start date: October 01, 2025
• End date: September 30, 2029
• Field of knowledge: Biological Sciences - Parasitology - Protozoology of Parasites
• Principal Investigator: Nilmar Silvio Moretti
• Grantee: Gabriela Gomes Alves
• 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

Leishmaniasis is a neglected tropical disease caused by protozoa of the genus Leishmania, transmitted by sandflies and responsible for a significant impact on public health in endemic regions. The parasite has a heteroxenous life cycle, characterized by alternating between different environments in the insect vector and the mammalian host, which requires high adaptive plasticity, supported by complex molecular mechanisms. Among these, post-translational modifications of proteins, as lysine acetylation being a regulatory process widely described in eukaryotes, capable of modulating both chromatin organization and various cytoplasmic functions. Despite its relevance, the role of acetylation and associated enzymes, such as lysine acetyltransferases and deacetylases (KDACs), remains poorly characterized in trypanosomatids. Preliminary results from our group indicate that DAC3 and DAC4 are located in the nucleus and may impact chromatin architecture and parasite differentiation, suggesting regulatory functions of an epigenetic nature. Given this context, this project aims to further characterize the functional role of DAC3 and DAC4 in Leishmania mexicana, covering the following areas: evaluating the impact of the absence of these enzymes on chromatin organization using transmission electron microscopy, micrococcal endonuclease digestion assays, and analysis of previously obtained ATAC-seq data; to map genomic regions of DAC3 and DAC4 interaction in strains expressing V5-tagged fusion proteins subjected to ChIP-seq; to identify protein partners by immunoprecipitation of recombinant proteins and Yeast Surface Display assays; and to investigate the role of these enzymes in DNA repair mechanisms against genotoxic agents. The execution of this project will elucidate how DAC3 and DAC4 contribute to chromatin regulation, nuclear plasticity, and genomic stability in L. mexicana, offering relevant conceptual advances for understanding the biology of the parasite and pointing to ways to explore epigenetic mechanisms in the context of leishmaniasis.