Alessandra Montecucco

Istituto di Genetica Molecolare “Luigi Luca Cavalli-Sforza”
Via Abbiategrasso, 207 – 27100 PAVIA
Phone: +39 0382 546351
E-mail: alessandra.montecucco@igm.cnr.it

Curriculum Vitae – Download

Complete List of Publications – Download



Research Activity

BIOCHEMICAL AND FUNCTIONAL CHARACTERIZATION OF ATP-DEPENDENT DNA LIGASES

DNA ligases catalyze the joining of single-strand or double-strand breaks between adjacent 3’-hydroxyl and 5’-phosphate termini in the phosphodiester backbone of double-strand DNA. For this reason, they play a vital role in DNA metabolism. Most eukaryotic DNA ligases use ATP as a cofactor. In mammalian cells there are three DNA ligases called DNA ligase I, III and IV. DNA strand breaks can occur as a result either of the direct action of DNA damaging agents or as reaction intermediates during DNA replication, repair and recombination; therefore, the sealing of these breaks by DNA ligase is critical for maintaining genome integrity. Most of the work carried out in my laboratory has led to the characterization of human DNA ligase I that is required for chromosomal DNA replication as well as for DNA-repair pathways. We showed that DNA ligase I-deficiency leads to replication stress, elicits the activation of ATM checkpoint pathway and triggers phosphorylation of histone variant H2AX. We applied OMICS approaches to investigate the impact of replication stress on chromatin organization and gene expression.

We are currently using DNA ligase I-defective cell lines, produced and characterized in my laboratory, as a model system to study the interactions between DNA replication, RNA metabolism and chromatin organization in the cellular response to replicative stress.

  

DNA REPLICATION

In mammalian cells DNA replication takes place at discrete nuclear sites called replication foci where newly synthesized DNA accumulates. Colocalization on replication foci of replicative enzymes gave rise to the idea that replication takes place within factories. The number and size of the replication factories vary throughout S phase according to a program that reflects the replication of various portions of the genome. Our group contributed to the analysis of several aspects. We have identified a short motif, that we called replication factory targeting sequence (RFTS), as the determinant sufficient to target DNA ligase I to replication factories. The identification of the RFTS opens the possibility to disassemble the factories by targeting specific peptides. This perspective could be relevant in the search of new anti-proliferative drugs. The RFTS overlaps an evolutionary conserved binding site for PCNA. We have also shown that cell cycle dependent phosphorylation of DNA ligase I is involved in the dynamic program of replication factories. Finally, we have shown that the ordered assembly and disassembly of replication factories is monitored by the cell cycle checkpoints and that the type of DNA damage, its distribution relative to the moving fork and the mechanism involved in the DNA damage recognition could determine the choice between stabilization and dispersal of replication factories in S phase.


DNA DAMAGE RESPONSE IN NON-REPLICATING CELLS

Genome integrity is threatened by endogenous and exogenous sources of DNA damage including reactive oxygen species (ROS) produced by cell metabolism. Cells respond to DNA damage by activating the DNA damage response (DDR), a signalling pathway that senses the damage and transduces the signal to effector proteins. The molecular mechanisms that sustain DDR have been mostly studied in proliferating cells were two main apical protein kinases, ATM (ataxia telangiectasia mutated) and ATR (ATM and Rad3-related kinase), are activated in response to double stranded DNA breaks and stalling of replication forks, respectively. Their activation leads to transient cell cycle arrest and activation of DNA damage repair mechanisms. Unlike proliferating cells, little is known about the events activating DDR in terminally differentiated cells. Non-replicating cells are hardly replaceable, thus accumulation of DNA damage that leads to cell senescence or apoptosis is detrimental for the organism resulting in loss of tissue functions. This is exemplified in neurodegenerative diseases, in which DNA damage is now considered a hallmark of ageing neurons and neurodegeneration.

We are studying the events activating the DNA damage response in terminally differentiated cells, evaluating the response of neurons to endogenous sources of DNA damage caused by mitochondrial dysfunction and fatty acids that mimic hypercaloric diet.


Recent Publications

2022

Capanni C; Schena E; Di Giampietro ML; Montecucco A; Mattioli E; Lattanzi G

The role of prelamin A post-translational maturation in stress response and 53BP1 recruitment Journal Article

In: Frontiers in cell and developmental biology, vol. 10, 2022.

Abstract | Links | BibTeX

2020

Giordano M; Infantino L; Biggiogera M; Montecucco A; Biamonti G

Heat Shock Affects Mitotic Segregation of Human Chromosomes Bound to Stress-Induced Satellite III RNAs Journal Article

In: International journal of molecular sciences, vol. 21, no. 8, pp. 2812, 2020.

Abstract | Links | BibTeX

2019

Magni M; Buscemi G; Maita L; Peng L; Chan SY; Montecucco A; Delia D; Zannini L

TSPYL2 is a novel regulator of SIRT1 and p300 activity in response to DNA damage. Journal Article

In: Cell death and differentiation, vol. 26, no. 5, pp. 918-931, 2019.

Abstract | Links | BibTeX

2018

Biamonti G; Maita L; Montecucco A

The Krebs Cycle Connection: Reciprocal Influence Between Alternative Splicing Programs and Cell Metabolism. Journal Article

In: Frontiers in oncology, vol. 8, pp. 408, 2018.

Abstract | Links | BibTeX

2017

Pignataro D; Francia S; Zanetta F; Brenna G; Brandini S; Olivieri A; Torroni A; Biamonti G; Montecucco A

A missense MT-ND5 mutation in differentiated Parkinson Disease cytoplasmic hybrid induces ROS-dependent DNA Damage Response amplified by DROSHA. Journal Article

In: Scientific reports, vol. 7, no. 1, pp. 9528, 2017.

Abstract | Links | BibTeX

2016

Montecucco A; Biamonti G

DNA and RNA metabolism meet at chromatin to control genome stability Journal Article

In: Frontiers in Genetics, vol. 7, pp. 67, 2016.

Links | BibTeX

2015

Cremaschi P; Oliverio M; Leva V; Bione S; Carriero R; Mazzucco G; Palamidessi A; Scita G; Biamonti G; Montecucco A

Chronic Replication Problems Impact Cell Morphology and Adhesion of DNA Ligase I Defective Cells. Journal Article

In: Plos One, vol. 10, no. 7, pp. e0130561, 2015.

Abstract | Links | BibTeX

Montecucco A; Zanetta F; Biamonti G

Molecular mechanisms of etoposide. Journal Article

In: EXCLI Journal, vol. 14, pp. 95-108, 2015.

Abstract | Links | BibTeX