WRN helicase and FEN-1 form a complex upon replication arrest and together process branchmigrating DNA structures associated with the replication fork.
Werner Syndrome is a premature aging disorder characterized by genomic instability, elevated recombination, and replication defects. It has been hypothesized that defective processing of certain replication fork structures by WRN may contribute to genomic instability. Fluorescence resonance energy transfer (FRET) analyses show that WRN and Flap Endonuclease-1 (FEN-1) form a complex in vivo that colocalizes in foci associated with arrested replication forks. WRN effectively stimulates FEN-1 cleavage of branch-migrating double-flap structures that are the physiological substrates of FEN-1 during replication. Biochemical analyses demonstrate that WRN helicase unwinds the chicken-foot HJ intermediate associated with a regressed replication fork and stimulates FEN-1 to cleave the unwound product in a structure-dependent manner. These results provide evidence for an interaction between WRN and FEN-1 in vivo and suggest that these proteins function together to process DNA structures associated with the replication fork.
Sharma
Sudha
S
Laboratory of Molecular Gerontology, National Institute on Aging, National Institutes of Health, Baltimore, Maryland 21224, USA.
Otterlei
Marit
M
Sommers
Joshua A
JA
Driscoll
Henry C
HC
Dianov
Grigory L
GL
Kao
Hui-I
HI
Bambara
Robert A
RA
Brosh
Robert M
RM
D004265:DNA Helicases / Q000235:genetics* / Q000378:metabolism; D004261:DNA Replication / Q000235:genetics* / Q000502:physiology; D024202:Electrophoretic Mobility Shift Assay / Q000379:methods; D005090:Exodeoxyribonucleases; D045585:Flap Endonucleases / Q000235:genetics* / Q000378:metabolism; D031541:Fluorescence Resonance Energy Transfer / Q000379:methods; D006367:HeLa Cells; D006801:Humans; D011485:Protein Binding; D053484:RecQ Helicases; D011994:Recombinant Proteins / Q000235:genetics* / Q000378:metabolism; D000071657:Werner Syndrome Helicase
D011994:Recombinant Proteins; D005090:Exodeoxyribonucleases; D045585:Flap Endonucleases; D004265:DNA Helicases; D053484:RecQ Helicases; C098785:WRN protein, human; D000071657:Werner Syndrome Helicase