AIRC IG2017. Exploiting the Drosophila model system to investigate the function of human proteins involved in telomere maintenance. (DSB.AD005.052)

Thematic area

Biomedical sciences

Project area

Structure responsible for the research project

Institute of molecular biology and pathology (IBPM)

Project manager

MAURIZIO GATTI
Phone number: 0649912842
Email: maurizio.gatti@uniroma1.it

Abstract

Telomeres play important roles in carcinogenesis. Critically short telomeres are sensed as DNA breaks leading to cell cycle arrest and cell senescence. Thus, most cancers sustain cell proliferation by reactivating telomerase, which is normally silent in somatic cells. Short and uncapped telomeres are also subjected to inappropriate DNA repair leading to telomere fusions, which can ultimately cause chromosome breakage promoting tumor development. Thus, any progress in understanding human telomere biology is likely to impact on cancer prevention and therapy. This proposal is aimed at the identification and characterization of new proteins involved in human telomere maintenance exploiting Drosophila as model system. Specifically we plan to further characterize two Drosophila telomeric proteins, Peo and DTgs1, and their human orthologues AKTIP and TGS1. Peo and AKTIP are E2 variant ubiquitin conjugating enzymes. DTgs1 and TGS1 catalyze the formation of a trimethyl guanosine cap at the 5' end of several RNAs. Our preliminary results indicate that TGS1 downregulates the RNA component of human telomerase (hTR).

Goals

The experiments we propose are aimed at defining the roles of Peo/AKTIP and DTgs1/TGS1at fly and human telomeres. We will characterize the roles Peo and AKTIP in H3K9 methylation and their functional relationships with known methyltransferases. We will use several strategies to determine whether Peo is involved in protein ubiquitination. We will exploit RNA IP and deep sequencing to characterize the RNAs bound DTgs1 and TGS1; we will also explore the molecular mechanisms leading to an increase in hTR in TGS1 mutant cells. In addition, we will perform Co-IP/MS to isolate Peo-interacting proteins. This experiment will be instrumental to understand the functional role of Peo and may lead to the identification of novel factors required for Drosophila telomere capping; some of these factors might have human homologues required for telomere maintenance. We expect to define the roles of Peo/AKTIP, DTgs1/TGS1 at Drosophila and mammalian telomeres, and to evaluate the efficiency of the combined Drosophila/human approach to unravel the functions of conserved telomere proteins.

Start date of activity

01/01/2018

Keywords

TELOMERI, DROSOPHILA, CANCRO

Last update: 28/04/2025