Please use this identifier to cite or link to this item:
Title: Nonenzymatic release of N7-methylguanine channels repair of abasic sites into an AP endonuclease-independent pathway in Arabidopsis.
Authors: Barbado, Casimiro
Córdoba-Cañero, Dolores
Ariza, Rafael R
Roldán-Arjona, Teresa
Keywords: AP endonucleases;AP lyases;N7-methylguanine;abasic sites;base excision repair
metadata.dc.subject.mesh: Arabidopsis
Arabidopsis Proteins
Binding Sites
Cell-Free System
DNA Damage
DNA Methylation
DNA Repair
DNA-(Apurinic or Apyrimidinic Site) Lyase
Gene Expression Regulation, Plant
Protein Domains
Issue Date: 16-Jan-2018
Abstract: Abasic (apurinic/apyrimidinic, AP) sites in DNA arise from spontaneous base loss or by enzymatic removal during base excision repair. It is commonly accepted that both classes of AP site have analogous biochemical properties and are equivalent substrates for AP endonucleases and AP lyases, although the relative roles of these two types of enzymes are not well understood. We provide here genetic and biochemical evidence that, in Arabidopsis, AP sites generated by spontaneous loss of N7-methylguanine (N7-meG) are exclusively repaired through an AP endonuclease-independent pathway initiated by FPG, a bifunctional DNA glycosylase with AP lyase activity. Abasic site incision catalyzed by FPG generates a single-nucleotide gap with a 3'-phosphate terminus that is processed by the DNA 3'-phosphatase ZDP before repair is completed. We further show that the major AP endonuclease in Arabidopsis (ARP) incises AP sites generated by enzymatic N7-meG excision but, unexpectedly, not those resulting from spontaneous N7-meG loss. These findings, which reveal previously undetected differences between products of enzymatic and nonenzymatic base release, may shed light on the evolution and biological roles of AP endonucleases and AP lyases.
metadata.dc.identifier.doi: 10.1073/pnas.1719497115
Appears in Collections:Producción 2020

Files in This Item:
File SizeFormat 
PMC5798382.pdf1,54 MBAdobe PDFView/Open

This item is protected by original copyright

This item is licensed under a Creative Commons License Creative Commons