Conserved motifs in nuclear genes encoding predicted mitochondrial proteins in Trypanosoma cruzi

PLoS One. 2019 Apr 9;14(4):e0215160. doi: 10.1371/journal.pone.0215160. eCollection 2019.

Abstract

Trypanosoma cruzi, the protozoan parasite that causes Chagas' disease, exhibits peculiar biological features. Among them, the presence of a unique mitochondrion is remarkable. Even though the mitochondrial DNA constitutes up to 25% of total cellular DNA, the structure and functionality of the mitochondrion are dependent on the expression of the nuclear genome. As in other eukaryotes, specific peptide signals have been proposed to drive the mitochondrial localization of a subset of trypanosomatid proteins. However, there are mitochondrial proteins encoded in the nuclear genome that lack of a peptide signal. In other eukaryotes, alternative protein targeting to subcellular organelles via mRNA localization has also been recognized and specific mRNA localization towards the mitochondria has been described. With the aim of seeking for mitochondrial localization signals in T. cruzi, we developed a strategy to build a comprehensive database of nuclear genes encoding predicted mitochondrial proteins (MiNT) in the TriTryps (T. cruzi, T. brucei and L. major). We found that approximately 15% of their nuclear genome encodes mitochondrial products. In T. cruzi the MiNT database reaches 1438 genes and a conserved peptide signal, M(L/F) R (R/S) SS, named TryM-TaPe is found in 60% of these genes, suggesting that the canonical mRNA guidance mechanism is present. In addition, the search for compositional signals in the transcripts of T. cruzi MiNT genes produce a list, being worth to note a conserved non-translated element represented by the consensus sequence DARRVSG. Taking into account its reported interaction with the T. brucei TRRM3 protein which is enriched in the mitochondrial membrane fraction, we here suggest a putative zip code role for this element. Globally, here we provide an inventory of the mitochondrial proteins in T. cruzi and give evidence for the existence of both peptide and mRNA signals specific to nuclear encoded mitochondrial proteins.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Amino Acid Sequence
  • Animals
  • Cell Nucleus / genetics
  • Computer Simulation
  • Conserved Sequence
  • DNA, Protozoan / genetics
  • Databases, Genetic
  • Genes, Protozoan*
  • Humans
  • Mitochondrial Proteins / genetics*
  • Protein Sorting Signals
  • Protozoan Proteins / genetics*
  • RNA, Messenger / genetics
  • RNA, Protozoan / genetics
  • Trypanosoma cruzi / genetics*
  • Trypanosoma cruzi / growth & development

Substances

  • DNA, Protozoan
  • Mitochondrial Proteins
  • Protein Sorting Signals
  • Protozoan Proteins
  • RNA, Messenger
  • RNA, Protozoan

Grants and funding

This work received financial support from: Programa de Desarrollo de las Ciencias Básicas to LB, PS and BG (http://www.pedeciba.edu.uy/indice.php); Agencia Nacional de Investigación e Innovación, FCE_2_2011_1_6924, to BG (http://www.anii.org.uy/); Comisión Sectorial de Investigación Científica de la Universidad de la República, Uruguay, proyecto Grupos I+D 2014 108725 to BG (http://www.csic.edu.uy/). The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.