A multi-approach analysis highlights the relevance of RPA-1 as a telomere end-binding protein (TEBP) in Leishmania amazonensis

Author(s):Show less -

Fernandes, Carlos A. H. ^{[1, 2]} ; Morea, Edna Gicela O. ^[3] ; dos Santos, Gabriel A. ^[3] ; da Silva, Vitor L. ^[3] ; Vieira, Marina Roveri ^[3] ; Viviescas, Maria Alejandra ^[3] ; Chatain, Jean ^[4] ; Vadel, Aurelie ^[4] ; Saintome, Carole ^{[4, 5]} ; Fontes, Marcos Roberto M. ^[2] ; Cano, Maria Isabel Nogueira ^[3]

Affiliation

^[1] Ecole Normale Super Paris Saclay, Lab Biol & Pharmacol Appl, Cachan - France

^[2] Sao Paulo State Univ UNESP, Biosci Inst, Dept Biophys & Pharmacol, Botucatu, SP - Brazil

^[3] Sao Paulo State Univ UNESP, Dept Chem & Biol Sci, Botucatu, SP - Brazil

^[4] INSERM U1154, MNHN CNRS UMR 7196, 43 Rue Cuvier, F-75005 Paris - France

^[5] Sorbonne Univ, UFR927, 4 Pl Jussieu, F-75005 Paris - France

• Document type: Journal article
• Source: BIOCHIMICA ET BIOPHYSICA ACTA-GENERAL SUBJECTS; v. 1864, n. 7 JUL 2020.
• Web of Science Citations: 0

Abstract

Background: Telomeres are chromosome end structures important in the maintenance of genome homeostasis. They are replenished by the action of telomerase and associated proteins, such as the OB (oligonucleotide/oligosaccharide-binding)-fold containing telomere-end binding proteins (TEBP) which plays an essential role in telomere maintenance and protection. The nature of TEBPs is well known in higher and some primitive eukaryotes, but it remains undetermined in trypanosomatids. Previous in silico searches have shown that there are no homologs of the classical TEPBs in trypanosomatids, including Leishmania sp. However, Replication Protein A subunit 1 (RPA-1), an OB-fold containing DNA-binding protein, was found co-localized with trypanosomatids telomeres and showed a high preference for the telomeric G-rich strand. Methods and results: We predicted the absence of structural homologs of OB-fold containing TEBPs in the Leishmania sp. genome using structural comparisons. We demonstrated by molecular docking that the ssDNA binding mode of LaRPA-1 shares features with the higher eukaryotes POT1 and RPA-1 crystal structures ssDNA binding mode. Using fluorescence spectroscopy, protein-DNA interaction assays, and FRET, we respectively show that LaRPA-1 shares some telomeric functions with the classical TEBPs since it can bind at least one telomeric repeat, protect the telomeric G-rich DNA from 3'-5' Exonuclease I digestion, and unfold telomeric G-quadruplex. Conclusions: Our results suggest that RPA-1 emerges as a TEBP in trypanosomatids, and in this context, we present two possible evolutionary landscapes of trypanosomatids RPA-1 that could reflect upon the evolution of OB-fold containing TEBPs from all eukaryotes. (AU)

• FAPESP's process: 15/17286-0 - Structural and functional studies aiming to understand the role of snake venoms toxins and how to inhibit their biological activity
• Grantee: Marcos Roberto de Mattos Fontes
• Support Opportunities: Regular Research Grants
• FAPESP's process: 18/04375-2 - Studies about the biogenesis and composition of the Leishmania spp. ribonucleoprotein complex and its regulation
• Grantee: Maria Isabel Nogueira Cano
• Support Opportunities: Research Projects - Thematic Grants
• FAPESP's process: 19/11496-3 - Role of TERRA in telomere regulation and replicative senescence in Leishmania major
• Grantee: Edna Gicela Ortiz Morea
• Support Opportunities: Scholarships in Brazil - Post-Doctoral