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

PLoS Negl Trop Dis. 2016 Dec 16;10(12):e0005181. doi: 10.1371/journal.pntd.0005181. eCollection 2016 Dec.

Abstract

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.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Cell Differentiation*
  • Chagas Disease
  • Computer Simulation
  • DNA, Protozoan / metabolism*
  • DNA, Single-Stranded / metabolism
  • Humans
  • Molecular Dynamics Simulation
  • Protein Binding
  • Protozoan Proteins / chemistry*
  • Protozoan Proteins / genetics
  • Protozoan Proteins / isolation & purification
  • Protozoan Proteins / metabolism*
  • Replication Protein A / chemistry*
  • Replication Protein A / genetics
  • Replication Protein A / isolation & purification
  • Replication Protein A / metabolism*
  • Trypanosoma cruzi / genetics
  • Trypanosoma cruzi / physiology*

Substances

  • DNA, Protozoan
  • DNA, Single-Stranded
  • Protozoan Proteins
  • Replication Protein A

Grants and funding

This work was supported by Fundação de Amparo a Pesquisa do Estado de São Paulo (FAPESP- fapesp.br), grant 2013/ 07467-1 and 2015/10580-0. RSP, MSdS, CAHF, and CBA are FAPESP fellowship (2014/02978-0; 2014/24170-5; 2013/17864-8; and 2014/13375-5). SPF, OAS, MRdMF, CRM, MIC and MCE are CNPq fellowship - PQ. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.