Replication Protein A Presents Canonical Functions and Is Also Involved in the Differentiation Capacity of Trypanosoma cruzi.

• Main Authors: Raphael Souza Pavani, Marcelo Santos da Silva, Carlos Alexandre Henrique Fernandes, Flavia Souza Morini, Christiane Bezerra Araujo, Marcos Roberto de Mattos Fontes, Osvaldo Augusto Sant'Anna, Carlos Renato Machado, Maria Isabel Cano, Stenio Perdigão Fragoso, Maria Carolina Elias
• Format: Article
• Language: English
• Published: Public Library of Science (PLoS) 2016-12-01
• Series: PLoS Neglected Tropical Diseases
• Online Access: http://europepmc.org/articles/PMC5161316?pdf=render
• ISSN: 1935-2727; 1935-2735

Replication Protein A (RPA), the major single stranded DNA binding protein in eukaryotes, is composed of three subunits and is a fundamental player in DNA metabolism, participating in replication, transcription, repair, and the DNA damage response. In human pathogenic trypanosomatids, only limited studies have been performed on RPA-1 from Leishmania. Here, we performed in silico, in vitro and in vivo analysis of Trypanosoma cruzi RPA-1 and RPA-2 subunits. Although computational analysis suggests similarities in DNA binding and Ob-fold structures of RPA from T. cruzi compared with mammalian and fungi RPA, the predicted tridimensional structures of T. cruzi RPA-1 and RPA-2 indicated that these molecules present a more flexible tertiary structure, suggesting that T. cruzi RPA could be involved in additional responses. Here, we demonstrate experimentally that the T. cruzi RPA complex interacts with DNA via RPA-1 and is directly related to canonical functions, such as DNA replication and DNA damage response. Accordingly, a reduction of TcRPA-2 expression by generating heterozygous knockout cells impaired cell growth, slowing down S-phase progression. Moreover, heterozygous knockout cells presented a better efficiency in differentiation from epimastigote to metacyclic trypomastigote forms and metacyclic trypomastigote infection. Taken together, these findings indicate the involvement of TcRPA in the metacyclogenesis process and suggest that a delay in cell cycle progression could be linked with differentiation in T. cruzi.