Two classes of BRC repeats in BRCA2 promote RAD51 nucleoprotein filament function by distinct mechanisms

Aura Carreira, Stephen C. Kowalczykowski

Research output: Contribution to journalArticle

69 Citations (Scopus)

Abstract

The human tumor suppressor protein BRCA2 plays a key role in recombinational DNA repair. BRCA2 recruits RAD51 to sites of DNA damage through interaction with eight conserved motifs of approximately 35 amino acids, the BRC repeats; however, the specific function of each repeat remains unclear. Here, we investigated the function of the individual BRC repeats by systematically analyzing their effects on RAD51 activities. Our results reveal the existence of two categories of BRC repeats that display unique functional characteristics. One group, comprising BRC1, -2, -3, and -4, binds to free RAD51 with high affinity. The second group, comprising BRC5, -6, -7, and -8, binds to free RAD51 with low affinity but binds to the RAD51-ssDNA filament with high affinity. Each member of the first group reduces the ATPase activity of RAD51, whereas none of the BRC repeats of the second group affects this activity. Thus, through different mechanisms, both types of BRC repeats bind to and stabilize the RAD51 nucleoprotein filament on ssDNA. In addition, members of the first group limit binding of RAD51 to duplex DNA, where members of the second group do not. Only the first group enhances DNA strand exchange by RAD51. Our results suggest that the two groups of BRC repeats have differentially evolved to ensure efficient formation of a nascent RAD51 filament on ssDNA by promoting its nucleation and growth, respectively. We propose that the BRC repeats cooperate in a partially redundant but reinforcing manner to ensure a high probability of RAD51 filament formation.

Original languageEnglish (US)
Pages (from-to)10448-10453
Number of pages6
JournalProceedings of the National Academy of Sciences of the United States of America
Volume108
Issue number26
DOIs
StatePublished - Jun 28 2011

Fingerprint

Nucleoproteins
Tumor Suppressor Proteins
Recombinational DNA Repair
DNA
DNA Damage
Adenosine Triphosphatases
Amino Acids
Growth

Keywords

  • Breast cancer
  • Cancer
  • Chromosome stability
  • DNA-break repair
  • Recombination

ASJC Scopus subject areas

  • General

Cite this

Two classes of BRC repeats in BRCA2 promote RAD51 nucleoprotein filament function by distinct mechanisms. / Carreira, Aura; Kowalczykowski, Stephen C.

In: Proceedings of the National Academy of Sciences of the United States of America, Vol. 108, No. 26, 28.06.2011, p. 10448-10453.

Research output: Contribution to journalArticle

@article{781301c666034902a85f94656bbe1ff9,
title = "Two classes of BRC repeats in BRCA2 promote RAD51 nucleoprotein filament function by distinct mechanisms",
abstract = "The human tumor suppressor protein BRCA2 plays a key role in recombinational DNA repair. BRCA2 recruits RAD51 to sites of DNA damage through interaction with eight conserved motifs of approximately 35 amino acids, the BRC repeats; however, the specific function of each repeat remains unclear. Here, we investigated the function of the individual BRC repeats by systematically analyzing their effects on RAD51 activities. Our results reveal the existence of two categories of BRC repeats that display unique functional characteristics. One group, comprising BRC1, -2, -3, and -4, binds to free RAD51 with high affinity. The second group, comprising BRC5, -6, -7, and -8, binds to free RAD51 with low affinity but binds to the RAD51-ssDNA filament with high affinity. Each member of the first group reduces the ATPase activity of RAD51, whereas none of the BRC repeats of the second group affects this activity. Thus, through different mechanisms, both types of BRC repeats bind to and stabilize the RAD51 nucleoprotein filament on ssDNA. In addition, members of the first group limit binding of RAD51 to duplex DNA, where members of the second group do not. Only the first group enhances DNA strand exchange by RAD51. Our results suggest that the two groups of BRC repeats have differentially evolved to ensure efficient formation of a nascent RAD51 filament on ssDNA by promoting its nucleation and growth, respectively. We propose that the BRC repeats cooperate in a partially redundant but reinforcing manner to ensure a high probability of RAD51 filament formation.",
keywords = "Breast cancer, Cancer, Chromosome stability, DNA-break repair, Recombination",
author = "Aura Carreira and Kowalczykowski, {Stephen C.}",
year = "2011",
month = "6",
day = "28",
doi = "10.1073/pnas.1106971108",
language = "English (US)",
volume = "108",
pages = "10448--10453",
journal = "Proceedings of the National Academy of Sciences of the United States of America",
issn = "0027-8424",
number = "26",

}

TY - JOUR

T1 - Two classes of BRC repeats in BRCA2 promote RAD51 nucleoprotein filament function by distinct mechanisms

AU - Carreira, Aura

AU - Kowalczykowski, Stephen C.

PY - 2011/6/28

Y1 - 2011/6/28

N2 - The human tumor suppressor protein BRCA2 plays a key role in recombinational DNA repair. BRCA2 recruits RAD51 to sites of DNA damage through interaction with eight conserved motifs of approximately 35 amino acids, the BRC repeats; however, the specific function of each repeat remains unclear. Here, we investigated the function of the individual BRC repeats by systematically analyzing their effects on RAD51 activities. Our results reveal the existence of two categories of BRC repeats that display unique functional characteristics. One group, comprising BRC1, -2, -3, and -4, binds to free RAD51 with high affinity. The second group, comprising BRC5, -6, -7, and -8, binds to free RAD51 with low affinity but binds to the RAD51-ssDNA filament with high affinity. Each member of the first group reduces the ATPase activity of RAD51, whereas none of the BRC repeats of the second group affects this activity. Thus, through different mechanisms, both types of BRC repeats bind to and stabilize the RAD51 nucleoprotein filament on ssDNA. In addition, members of the first group limit binding of RAD51 to duplex DNA, where members of the second group do not. Only the first group enhances DNA strand exchange by RAD51. Our results suggest that the two groups of BRC repeats have differentially evolved to ensure efficient formation of a nascent RAD51 filament on ssDNA by promoting its nucleation and growth, respectively. We propose that the BRC repeats cooperate in a partially redundant but reinforcing manner to ensure a high probability of RAD51 filament formation.

AB - The human tumor suppressor protein BRCA2 plays a key role in recombinational DNA repair. BRCA2 recruits RAD51 to sites of DNA damage through interaction with eight conserved motifs of approximately 35 amino acids, the BRC repeats; however, the specific function of each repeat remains unclear. Here, we investigated the function of the individual BRC repeats by systematically analyzing their effects on RAD51 activities. Our results reveal the existence of two categories of BRC repeats that display unique functional characteristics. One group, comprising BRC1, -2, -3, and -4, binds to free RAD51 with high affinity. The second group, comprising BRC5, -6, -7, and -8, binds to free RAD51 with low affinity but binds to the RAD51-ssDNA filament with high affinity. Each member of the first group reduces the ATPase activity of RAD51, whereas none of the BRC repeats of the second group affects this activity. Thus, through different mechanisms, both types of BRC repeats bind to and stabilize the RAD51 nucleoprotein filament on ssDNA. In addition, members of the first group limit binding of RAD51 to duplex DNA, where members of the second group do not. Only the first group enhances DNA strand exchange by RAD51. Our results suggest that the two groups of BRC repeats have differentially evolved to ensure efficient formation of a nascent RAD51 filament on ssDNA by promoting its nucleation and growth, respectively. We propose that the BRC repeats cooperate in a partially redundant but reinforcing manner to ensure a high probability of RAD51 filament formation.

KW - Breast cancer

KW - Cancer

KW - Chromosome stability

KW - DNA-break repair

KW - Recombination

UR - http://www.scopus.com/inward/record.url?scp=79960597176&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=79960597176&partnerID=8YFLogxK

U2 - 10.1073/pnas.1106971108

DO - 10.1073/pnas.1106971108

M3 - Article

C2 - 21670257

AN - SCOPUS:79960597176

VL - 108

SP - 10448

EP - 10453

JO - Proceedings of the National Academy of Sciences of the United States of America

JF - Proceedings of the National Academy of Sciences of the United States of America

SN - 0027-8424

IS - 26

ER -