Complementary Functions of Plant AP Endonucleases and AP Lyases during DNA Repair of Abasic Sites Arising from C:G Base Pairs.
Int J Mol Sci
; 22(16)2021 Aug 16.
Article
en En
| MEDLINE
| ID: mdl-34445469
Abasic (apurinic/apyrimidinic, AP) sites are ubiquitous DNA lesions arising from spontaneous base loss and excision of damaged bases. They may be processed either by AP endonucleases or AP lyases, but the relative roles of these two classes of enzymes are not well understood. We hypothesized that endonucleases and lyases may be differentially influenced by the sequence surrounding the AP site and/or the identity of the orphan base. To test this idea, we analysed the activity of plant and human AP endonucleases and AP lyases on DNA substrates containing an abasic site opposite either G or C in different sequence contexts. AP sites opposite G are common intermediates during the repair of deaminated cytosines, whereas AP sites opposite C frequently arise from oxidized guanines. We found that the major Arabidopsis AP endonuclease (ARP) exhibited a higher efficiency on AP sites opposite G. In contrast, the main plant AP lyase (FPG) showed a greater preference for AP sites opposite C. The major human AP endonuclease (APE1) preferred G as the orphan base, but only in some sequence contexts. We propose that plant AP endonucleases and AP lyases play complementary DNA repair functions on abasic sites arising at C:G pairs, neutralizing the potential mutagenic consequences of C deamination and G oxidation, respectively.
Palabras clave
Texto completo:
1
Colección:
01-internacional
Base de datos:
MEDLINE
Asunto principal:
Daño del ADN
/
Arabidopsis
/
Emparejamiento Base
/
ADN-(Sitio Apurínico o Apirimidínico) Liasa
/
Reparación del ADN
/
Endonucleasas
Límite:
Humans
Idioma:
En
Revista:
Int J Mol Sci
Año:
2021
Tipo del documento:
Article
País de afiliación:
España
Pais de publicación:
Suiza