Naslov
Tyrosyl DNA phosphodiesterase 1 repairs different types of DPCs in vivo

Autori
Anticevic, Ivan ; Otten, Cecile ; Jukic, Luka ; Vinkovic, Luka ; Popovic, Marta

Vrsta, podvrsta i kategorija rada
Sažeci sa skupova, sažetak, znanstveni

Izvornik
Book of Abstracts, “At the Intersection of DNA Replication and Genome Maintenance: from Mechanisms to Therapy” / - Udine, 2022, 49-49

Skup
At the Intersection of DNA Replication and Genome Maintenance: from Mechanisms to Therapy

Mjesto i datum
Trst, Italija, 05.07.2022. - 07.07.2022

Vrsta sudjelovanja
Poster

Vrsta recenzije
Podatak o recenziji nije dostupan

Ključne riječi
TDP1, DPC, SPRTN, Topoisomerase 1,

Sažetak
DNA-protein crosslink (DPC) is a type of DNA lesion in which a protein becomes irreversibly bound to DNA and affects all DNA transactions, which in turn can lead to the formation of DSBs, genomic instability, and/or cell death. DPCs include (1) enzymatic DPCs formed by proteins that normally bind to DNA but become trapped when exposed to endogenous or exogenous DPC inducers, and (2) general DPCs formed by various cellular proteins in the vicinity of DNA that become crosslinked in the presence of DPC inducers. The different types of DPCs require distinct repair pathways, ranging from general to specifi c repair mechanisms. Tyrosyl DNA phosphodiesterase 1 is a very well-studied enzyme known to be involved in the repair of one of the most common enzymatic DPCs, topoisomerase 1-DNA covalent complex. Topoisomerase 1 catalyzes single-strand breakage to release torsional stress on DNA. As a DPC, it remains bound to the 3’ end of the DNA. Initially, TOP1 is cleaved by SPRTN, leaving a peptide residue that is removed by the phosphodiesterase activity of TDP1. The unrepaired TOP1-DNA covalent complex affects all DNA transactions, and the single-strand break eventually becomes a double break, leading to genome instability. In addition, a mutation in the catalytic domain of the TDP1 protein leads to SCAN1 syndrome, a neurological disorder characterized by slowly progressive cerebellar ataxia in late childhood. The involvement of TDP1 in TOP1cc repair has been demonstrated both in vitro and in cell models. In vitro, TDP1 can also remove other peptide residues and small proteins such as histones bound to the 3’ end of DNA. Are all these repair functions of TDP1 also present at the organismal level? To address this question, we created a Tdp1 mutant line of zebrafi sh (Danio rerio) into which we introduced the codon STOP at the beginning of the Tdp1 gene using the CRISPR/Cas system. We isolated DPCs from mutant and wild-type embryos and measured changes in total and specifi c DPC levels. We also reduced mRNA levels of SPRTN protein in Tdp1-/- embryos and measured the effects of SPRTN and TDP1 interplay. Our animal model will reveal the role of Tdp1 enzyme in DPC repair (DPCR) at the organismal level and the relationship between Tdp1 and SPRTN protease within DPCR pathways. These fi ndings will expand the knowledge of the role of TDP1 protein in DNA repair at the organismal level, which may contribute to the improvement of cancer therapy and the understanding of diseases caused by TDP1 defi ciencies.

Izvorni jezik
Engleski

Znanstvena područja
Biologija

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