Header

UZH-Logo

Maintenance Infos

Cleavage of the Bloom's syndrome gene product during apoptosis by caspase-3 results in an impaired interaction with topoisomerase IIIalpha


Freire, R (2001). Cleavage of the Bloom's syndrome gene product during apoptosis by caspase-3 results in an impaired interaction with topoisomerase IIIalpha. Nucleic Acids Research, 29(15):3172-3180.

Abstract

In higher eukaryotes, the integration of signals triggered in response to certain types of stress can result in programmed cell death. Central to these events is the sequential activation of a cascade of proteinases known as caspases. The final activated effector caspases of this cascade digest a number of cellular proteins, in some cases increasing their enzymatic activity, in others destroying their function. Of the proteins shown to be targets for caspase-mediated proteolysis, a surprisingly large proportion are proteins involved in the signalling or repair of DNA damage. Here we investigate whether BLM, the product of the gene mutated in Bloom's syndrome, a human autosomal disease characterised by cancer predisposition and sunlight sensitivity, is cleaved during apoptosis. BLM interacts with topoisomerase IIIα and has been proposed to play an important role in maintaining genomic integrity through its roles in DNA repair and replication. We show that BLM is cleaved during apoptosis by caspase-3 and reveal that the main cleavage site is located at the junction between the N-terminal and central helicase domains of BLM. Proteolytic cleavage by caspase-3 produces a 120 kDa fragment, which contains the intact helicase domain and three smaller fragments, the relative amounts of which depend on time of incubation with caspase-3. The 120 kDa fragment retains the helicase activity of the intact BLM protein. However, its interaction with topoisomerase IIIα is severely impaired. Since the BLM-topoisomerase interaction is believed to be necessary for many of the replication and recombination functions of BLM, we suggest that caspase-3 cleavage of BLM could alter the localisation and/or function of BLM and that these changes may be important in the process of apoptosis

Abstract

In higher eukaryotes, the integration of signals triggered in response to certain types of stress can result in programmed cell death. Central to these events is the sequential activation of a cascade of proteinases known as caspases. The final activated effector caspases of this cascade digest a number of cellular proteins, in some cases increasing their enzymatic activity, in others destroying their function. Of the proteins shown to be targets for caspase-mediated proteolysis, a surprisingly large proportion are proteins involved in the signalling or repair of DNA damage. Here we investigate whether BLM, the product of the gene mutated in Bloom's syndrome, a human autosomal disease characterised by cancer predisposition and sunlight sensitivity, is cleaved during apoptosis. BLM interacts with topoisomerase IIIα and has been proposed to play an important role in maintaining genomic integrity through its roles in DNA repair and replication. We show that BLM is cleaved during apoptosis by caspase-3 and reveal that the main cleavage site is located at the junction between the N-terminal and central helicase domains of BLM. Proteolytic cleavage by caspase-3 produces a 120 kDa fragment, which contains the intact helicase domain and three smaller fragments, the relative amounts of which depend on time of incubation with caspase-3. The 120 kDa fragment retains the helicase activity of the intact BLM protein. However, its interaction with topoisomerase IIIα is severely impaired. Since the BLM-topoisomerase interaction is believed to be necessary for many of the replication and recombination functions of BLM, we suggest that caspase-3 cleavage of BLM could alter the localisation and/or function of BLM and that these changes may be important in the process of apoptosis

Statistics

Citations

Dimensions.ai Metrics

Altmetrics

Downloads

15 downloads since deposited on 25 Sep 2018
7 downloads since 12 months
Detailed statistics

Additional indexing

Item Type:Journal Article, refereed, original work
Communities & Collections:National licences > 142-005
Dewey Decimal Classification:570 Life sciences; biology
610 Medicine & health
Language:English
Date:1 August 2001
Deposited On:25 Sep 2018 12:55
Last Modified:03 Aug 2020 02:17
Publisher:Oxford University Press
ISSN:0305-1048
OA Status:Hybrid
Publisher DOI:https://doi.org/10.1093/nar/29.15.3172
Related URLs:https://www.swissbib.ch/Search/Results?lookfor=nationallicenceoxford101093nar29153172 (Library Catalogue)

Download

Hybrid Open Access

Download PDF  'Cleavage of the Bloom's syndrome gene product during apoptosis by caspase-3 results in an impaired interaction with topoisomerase IIIalpha'.
Preview
Content: Published Version
Language: English
Filetype: PDF (Nationallizenz 142-005)
Size: 372kB
View at publisher