TY - JOUR

T1 - Functional roles of parp2 in assembling protein–protein complexes involved in base excision dna repair

AU - Vasil’eva, Inna

AU - Moor, Nina

AU - Anarbaev, Rashid

AU - Kutuzov, Mikhail

AU - Lavrik, Olga

N1 - Funding Information: Funding: This research was funded by the Russian Science Foundation, grant numbers 19‐14‐00107 (protein–protein interaction study by fluorescence‐based and DLS experiments) and 20‐14‐00086 (DLS experiments with PARylated proteins), and by the Russian State funded project, number 0245‐ 2021‐0009 (expression and purification, activity testing, fluorescent labelling of proteins). Publisher Copyright: © 2021 by the authors. Licensee MDPI, Basel, Switzerland. Copyright: Copyright 2021 Elsevier B.V., All rights reserved.

PY - 2021/5/1

Y1 - 2021/5/1

N2 - Poly(ADP‐ribose) polymerase 2 (PARP2) participates in base excision repair (BER) along-side PARP1, but its functions are still under study. Here, we characterize binding affinities of PARP2 for other BER proteins (PARP1, APE1, Polβ, and XRCC1) and oligomerization states of the homo-and hetero‐associated complexes using fluorescence‐based and light scattering techniques. To com-pare PARP2 and PARP1 in the efficiency of PAR synthesis, in the absence and presence of protein partners, the size of PARP2 PARylated in various reaction conditions was measured. Unlike PARP1, PARP2 forms more dynamic complexes with common protein partners, and their stability is effectively modulated by DNA intermediates. Apparent binding affinity constants determined for homo-and hetero‐oligomerized PARP1 and PARP2 provide evidence that the major form of PARP2 at ex-cessive PARP1 level is their heterocomplex. Autoregulation of PAR elongation at high PARP and NAD+ concentrations is stronger for PARP2 than for PARP1, and the activity of PARP2 is more effectively inhibited by XRCC1. Moreover, the activity of both PARP1 and PARP2 is suppressed upon their heteroPARylation. Taken together, our findings suggest that PARP2 can function differ-ently in BER, promoting XRCC1‐dependent repair (similarly to PARP1) or an alternative XRCC1‐ independent mechanism via hetero‐oligomerization with PARP1.

AB - Poly(ADP‐ribose) polymerase 2 (PARP2) participates in base excision repair (BER) along-side PARP1, but its functions are still under study. Here, we characterize binding affinities of PARP2 for other BER proteins (PARP1, APE1, Polβ, and XRCC1) and oligomerization states of the homo-and hetero‐associated complexes using fluorescence‐based and light scattering techniques. To com-pare PARP2 and PARP1 in the efficiency of PAR synthesis, in the absence and presence of protein partners, the size of PARP2 PARylated in various reaction conditions was measured. Unlike PARP1, PARP2 forms more dynamic complexes with common protein partners, and their stability is effectively modulated by DNA intermediates. Apparent binding affinity constants determined for homo-and hetero‐oligomerized PARP1 and PARP2 provide evidence that the major form of PARP2 at ex-cessive PARP1 level is their heterocomplex. Autoregulation of PAR elongation at high PARP and NAD+ concentrations is stronger for PARP2 than for PARP1, and the activity of PARP2 is more effectively inhibited by XRCC1. Moreover, the activity of both PARP1 and PARP2 is suppressed upon their heteroPARylation. Taken together, our findings suggest that PARP2 can function differ-ently in BER, promoting XRCC1‐dependent repair (similarly to PARP1) or an alternative XRCC1‐ independent mechanism via hetero‐oligomerization with PARP1.

KW - Base excision repair

KW - Dynamic light scattering

KW - Fluorescence techniques

KW - PARP1

KW - PARP2

KW - Poly(ADP‐ribosyl)ation

KW - Protein–protein interaction

UR - http://www.scopus.com/inward/record.url?scp=85104823385&partnerID=8YFLogxK

U2 - 10.3390/ijms22094679

DO - 10.3390/ijms22094679

M3 - Article

C2 - 33925170

AN - SCOPUS:85104823385

VL - 22

JO - International Journal of Molecular Sciences

JF - International Journal of Molecular Sciences

SN - 1661-6596

IS - 9

M1 - 4679

ER -