Articolo in rivista, 2017, ENG, 10.1093/nar/gkw1275

Ribonucleotide incorporation by human DNA polymerase eta impacts translesion synthesis and RNase H2 activity

Mentegari E.; Crespan E.; Bavagnoli L.; Kissova M.; Bertoletti F.; Sabbioneda S.; Imhof R.; Sturla S.J.; Nilforoushan A.; Hubscher U.; Van Loon B.; Maga G.

DNA Enzymology and Molecular Virology, Cell Nucleus and DNA replication Units, Institute of Molecular Genetics IGM-CNR, via Abbiategrasso 207, Pavia, I-27100, , Italy; Department of Molecular Mechanisms of Disease, University of Zürich, Winterthurerstrasse 190, Zürich, CH-8057, , Switzerland; Department of Health Sciences and Technology, ETH Zurich, Schmelzbergstrasse 9, Zürich, CH-8092, , Switzerland

Ribonucleotides (rNs) incorporated in the genome by DNA polymerases (Pols) are removed by RNase H2. Cytidine and guanosine preferentially accumulate over the other rNs. Here we show that human Pol ? can incorporate cytidine monophosphate (rCMP) opposite guanine, 8-oxo-7,8-dihydroguanine, 8-methyl-2'-deoxyguanosine and a cisplatin intrastrand guanine crosslink (cis-PtGG), while it cannot bypass a 3-methylcytidine or an abasic site with rNs as substrates. Pol eta is also capable of synthesizing polyribonucleotide chains, and its activity is enhanced by its auxiliary factor DNA Pol delta interacting protein 2 (PolDIP2). Human RNase H2 removes cytidine and guanosine less efficiently than the other rNs and incorporation of rCMP opposite DNA lesions further reduces the efficiency of RNase H2. Experiments with XP-V cell extracts indicate Pol eta as the major basis of rCMP incorporation opposite cis-PtGG. These results suggest that translesion synthesis by Pol eta can contribute to the accumulation of rCMP in the genome, particularly opposite modified guanines.

Nucleic acids research (Online) 45 (5), pp. 2600–2614

Keywords

polymerase eta

CNR authors

Maga Giovanni, Crespan Emmanuele, Sabbioneda Simone

CNR institutes

IGM – Istituto di genetica molecolare "Luigi Luca Cavalli Sforza"