Werner syndrome protein interacts with human flap endonuclease 1 and stimulates its cleavage activity.
Werner syndrome (WS) is a human premature aging disorder characterized by chromosomal instability. The cellular defects of WS presumably reflect compromised or aberrant function of a DNA metabolic pathway that under normal circumstances confers stability to the genome. We report a novel interaction of the WRN gene product with the human 5' flap endonuclease/5'-3' exonuclease (FEN-1), a DNA structure-specific nuclease implicated in DNA replication, recombination and repair. WS protein (WRN) dramatically stimulates the rate of FEN-1 cleavage of a 5' flap DNA substrate. The WRN-FEN-1 functional interaction is independent of WRN catalytic function and mediated by a 144 amino acid domain of WRN that shares homology with RecQ DNA helicases. A physical interaction between WRN and FEN-1 is demonstrated by their co-immunoprecipitation from HeLa cell lysate and affinity pull-down experiments using a recombinant C-terminal fragment of WRN. The underlying defect of WS is discussed in light of the evidence for the interaction between WRN and FEN-1.
Brosh
R M
RM
Laboratory of Molecular Gerontology, National Institute on Aging, National Institutes of Health, 5600 Nathan Shock Drive, Baltimore, MD 21224, USA. BroshR@grc.nia.nih.gov
von Kobbe
C
C
Sommers
J A
JA
Karmakar
P
P
Opresko
P L
PL
Piotrowski
J
J
Dianova
I
I
Dianov
G L
GL
Bohr
V A
VA
D000251:Adenosine Triphosphatases / Q000502:physiology; D002384:Catalysis; D004247:DNA / Q000378:metabolism; D004265:DNA Helicases / Q000737:chemistry / Q000502:physiology*; D004268:DNA-Binding Proteins / Q000502:physiology; D004706:Endodeoxyribonucleases / Q000737:chemistry / Q000378:metabolism*; D004789:Enzyme Activation; D005090:Exodeoxyribonucleases; D005092:Exonucleases / Q000502:physiology; D045585:Flap Endonucleases; D006367:HeLa Cells; D006801:Humans; D046911:Macromolecular Substances; D010446:Peptide Fragments / Q000378:metabolism; D018809:Proliferating Cell Nuclear Antigen / Q000502:physiology; D017434:Protein Structure, Tertiary; D053484:RecQ Helicases; D011993:Recombinant Fusion Proteins / Q000378:metabolism; D051716:Replication Protein A; D014898:Werner Syndrome / Q000235:genetics*; D000071657:Werner Syndrome Helicase
D004268:DNA-Binding Proteins; D046911:Macromolecular Substances; D010446:Peptide Fragments; D018809:Proliferating Cell Nuclear Antigen; C497167:RPA1 protein, human; D011993:Recombinant Fusion Proteins; D051716:Replication Protein A; D004247:DNA; D004706:Endodeoxyribonucleases; D005090:Exodeoxyribonucleases; D005092:Exonucleases; D045585:Flap Endonucleases; C468317:FEN1 protein, human; D000251:Adenosine Triphosphatases; D004265:DNA Helicases; D053484:RecQ Helicases; C098785:WRN protein, human; D000071657:Werner Syndrome Helicase