Functional and structural studies of the PinX1 orthologue and its influence on Leishmania spp telomeres

• Grant number: 21/14798-0
• Support Opportunities: Scholarships in Brazil - Doctorate (Direct)
• Start date: July 01, 2022
• End date: February 28, 2026
• Field of knowledge: Biological Sciences - Genetics - Molecular Genetics and Genetics of Microorganisms
• Principal Investigator: Maria Isabel Nogueira Cano
• Grantee: Stephany Cacete de Paiva
• Host Institution: Instituto de Biociências (IBB). Universidade Estadual Paulista (UNESP). Campus de Botucatu. Botucatu , SP, Brazil
• Associated research grant: 18/04375-2 - Studies about the biogenesis and composition of the Leishmania spp. ribonucleoprotein complex and its regulation, AP.TEM

Abstract

Leishmaniasis is a set of diseases that show different outcomes and can be expressed in different clinical forms such as cutaneous, mucocutaneous, and visceral (kala-azar). The disease is transmited by the bite of a female sandfly contaminated by protozoa of the Leishmania genus. The available treatments present low efficacy, high toxicity, and high cost leading to parasite resistance, which justifyes the search for new therapies and drug targets. Leishmania spp. telomeres are potential targets for the development of new drugs and understanding the biology of this structure is necessary. Telomeres are the physical ends of linear chromosomes and are directly implicated in maintaining the genomic stability since they avoid terminal degradation and fusions which are deleterious for cell homeostasis. Parasite's telomeres similar to other eukaryotes, are maintained by telomerase whose function is also regulated by proteins associated with the complex and by telomeric proteins that make the activity of the complex effective and stable. Until now, among the trypanosomatids, the Leishmania amazonensis telomeric complex is the best characterized, although little is known about the biogenesis and the exact composition of the telomerase ribonucleoprotein (RNP) complex. Preliminary results from our group indicate that in the genome of Leishmania spp. there is an ortholog for one of these regulatory proteins, the PinX1 protein, considered an accessory protein of the telomerase RNP complex. In model eukaryotes, PinX1 acts as a natural inhibitor of enzyme activity since it sequesters the telomerase TERT component from the complex. The Leishmania PinX1 orthologue presents the conserved glycine-rich N-terminal domain (G-patch) and a less conserved TID domain (Telomerase Inhibitory Domain) at the C-terminal, which respectively interacts with the TERT and the mammalian TRF1 protein. Our goal is to perform biophysical tests seeking to elucidate the Leishmania spp. PinX1 structure and its interactions with the TERT and TER components, as well as to initiate functional studies by performing the overexpression and the knocking out of PinX1. (AU)

Scientific publications

(References retrieved automatically from Web of Science and SciELO through information on FAPESP grants and their corresponding numbers as mentioned in the publications by the authors)

ASSIS, LUIZ HENRIQUE DE CASTRO; DE PAIVA, STEPHANY CACETE; CANO, MARIA ISABEL NOGUEIRA. Behind Base J: The Roles of JBP1 and JBP2 on Trypanosomatids. PATHOGENS, v. 12, n. 3, p. 14-pg., 2023-03-01. (21/04253-7, 21/14798-0, 18/04375-2)

DA SILVA, VITOR LUIZ; DE PAIVA, STEPHANY CACETE; DE OLIVEIRA, HAMINE CRISTINA; FERNANDES, CARLOS ALEXANDRE H.; SALVADOR, GUILHERME HENRIQUE MARCHI; FONTES, MARCOS ROBERTO DE M.; CANO, MARIA ISABEL N.. Biochemical and structural characterization of the RT domain of Leishmania sp. telomerase reverse transcriptase. BIOCHIMICA ET BIOPHYSICA ACTA-GENERAL SUBJECTS, v. 1867, n. 11, p. 10-pg., 2023-09-28. (19/05958-4, 21/14798-0, 18/04375-2, 19/05239-8)