Cockayne syndrome B protein stimulates apurinic endonuclease 1 activity and protects against agents that introduce base excision repair intermediates.

ABSTRACT: The Cockayne syndrome B (CSB) protein--defective in a majority of patients suffering from the rare autosomal disorder CS--is a member of the SWI2/SNF2 family with roles in DNA repair and transcription. We demonstrate herein that purified recombinant CSB and the major human apurinic/apyrimidinic (AP) endonuclease, APE1, physically and functionally interact. CSB stimulates the AP site incision activity of APE1 on normal (i.e. fully paired) and bubble AP-DNA substrates, with the latter being more pronounced (up to 6-fold). This activation is ATP-independent, and specific for the human CSB and full-length APE1 protein, as no CSB-dependent stimulation was observed with Escherichia coli endonuclease IV or an N-terminal truncated APE1 fragment. CSB and APE1 were also found in a common protein com

SUBMITTER: Wong HK 

PROVIDER: S-EPMC1919475 | biostudies-literature | 2007

REPOSITORIES: biostudies-literature