TY - JOUR

T1 - Functional role of N-terminal extension of human ap endonuclease 1 in coordination of base excision dna repair via protein–protein interactions

AU - Moor, Nina

AU - Vasil’eva, Inna

AU - Lavrik, Olga

PY - 2020/4/28

Y1 - 2020/4/28

N2 - Human apurinic/apyrimidinic endonuclease 1 (APE1) has multiple functions in base excision DNA repair (BER) and other cellular processes. Its eukaryote-specific N-terminal extension plays diverse regulatory roles in interaction with different partners. Here, we explored its involvement in interaction with canonical BER proteins. Using fluorescence based-techniques, we compared binding affinities of the full-length and N-terminally truncated forms of APE1 (APE1N∆35 and APE1N∆61) for functionally and structurally different DNA polymerase β (Polβ), X-ray repair cross-complementing protein 1 (XRCC1), and poly(adenosine diphosphate (ADP)-ribose) polymerase 1 (PARP1), in the absence and presence of model DNA intermediates. Influence of the N-terminal truncation on binding the AP site-containing DNA was additionally explored. These data suggest that the interaction domain for proteins is basically formed by the conserved catalytic core of APE1. The N-terminal extension being capable of dynamically interacting with the protein and DNA partners is mostly responsible for DNA-dependent modulation of protein–protein interactions. Polβ, XRCC1, and PARP1 were shown to more efficiently regulate the endonuclease activity of the full-length protein than that of APE1N∆61, further suggesting contribution of the N-terminal extension to BER coordination. Our results advance the understanding of functional roles of eukaryote-specific protein extensions in highly coordinated BER processes.

AB - Human apurinic/apyrimidinic endonuclease 1 (APE1) has multiple functions in base excision DNA repair (BER) and other cellular processes. Its eukaryote-specific N-terminal extension plays diverse regulatory roles in interaction with different partners. Here, we explored its involvement in interaction with canonical BER proteins. Using fluorescence based-techniques, we compared binding affinities of the full-length and N-terminally truncated forms of APE1 (APE1N∆35 and APE1N∆61) for functionally and structurally different DNA polymerase β (Polβ), X-ray repair cross-complementing protein 1 (XRCC1), and poly(adenosine diphosphate (ADP)-ribose) polymerase 1 (PARP1), in the absence and presence of model DNA intermediates. Influence of the N-terminal truncation on binding the AP site-containing DNA was additionally explored. These data suggest that the interaction domain for proteins is basically formed by the conserved catalytic core of APE1. The N-terminal extension being capable of dynamically interacting with the protein and DNA partners is mostly responsible for DNA-dependent modulation of protein–protein interactions. Polβ, XRCC1, and PARP1 were shown to more efficiently regulate the endonuclease activity of the full-length protein than that of APE1N∆61, further suggesting contribution of the N-terminal extension to BER coordination. Our results advance the understanding of functional roles of eukaryote-specific protein extensions in highly coordinated BER processes.

KW - APE1

KW - Base excision repair

KW - Fluorescence techniques

KW - Multifunctional disordered protein

KW - Protein

KW - Protein interactions

KW - GLYCOSYLASE

KW - DOMAIN

KW - RECOGNITION

KW - fluorescence techniques

KW - base excision repair

KW - HUMAN APURINIC/APYRIMIDINIC ENDONUCLEASE-1

KW - XRCC1

KW - multifunctional disordered protein

KW - protein-protein interactions

KW - BETA

KW - LYSINE RESIDUES

KW - HUMAN APURINIC ENDONUCLEASE

KW - POLY(ADP-RIBOSE) POLYMERASE-1

KW - BINDING

UR - http://www.scopus.com/inward/record.url?scp=85083958837&partnerID=8YFLogxK

U2 - 10.3390/ijms21093122

DO - 10.3390/ijms21093122

M3 - Article

C2 - 32354179

AN - SCOPUS:85083958837

VL - 21

JO - International Journal of Molecular Sciences

JF - International Journal of Molecular Sciences

SN - 1661-6596

IS - 9

M1 - 3122

ER -