Mutational analysis of the human nucleotide excision repair gene ERCC1.
The human DNA repair protein ERCC1 resides in a complex together with the ERCC4, ERCC11 and XP-F correcting activities, thought to perform the 5' strand incision during nucleotide excision repair (NER). Its yeast counterpart, RAD1-RAD10, has an additional engagement in a mitotic recombination pathway, probably required for repair of DNA cross-links. Mutational analysis revealed that the poorly conserved N-terminal 91 amino acids of ERCC1 are dispensable for both repair functions, in contrast to a deletion of only four residues from the C-terminus. A database search revealed a strongly conserved motif in this C-terminus sharing sequence homology with many DNA break processing proteins, indicating that this part is primarily required for the presumed structure-specific endonuclease activity of ERCC1. Most missense mutations in the central region give rise to an unstable protein (complex). Accordingly, we found that free ERCC1 is very rapidly degraded, suggesting that protein-protein interactions provide stability. Survival experiments show that the removal of cross-links requires less ERCC1 than UV repair. This suggests that the ERCC1-dependent step in cross-link repair occurs outside the context of NER and provides an explanation for the phenotype of the human repair syndrome xeroderma pigmentosum group F.
Sijbers
A M
AM
Department of Cell Biology and Genetics, Erasmus University, Rotterdam, The Netherlands.
van der Spek
P J
PJ
Odijk
H
H
van den Berg
J
J
van Duin
M
M
Westerveld
A
A
Jaspers
N G
NG
Bootsma
D
D
Hoeijmakers
J H
JH
D000595:Amino Acid Sequence; D000818:Animals; D002945:Cisplatin / Q000494:pharmacology; D017124:Conserved Sequence; D004252:DNA Mutational Analysis; D004260:DNA Repair / Q000235:genetics*; D018076:DNA, Complementary / Q000235:genetics; D004268:DNA-Binding Proteins; D004307:Dose-Response Relationship, Radiation; D004720:Endonucleases / Q000235:genetics*; D005784:Gene Amplification; D005816:Genetic Complementation Test; D006801:Humans; D016685:Mitomycin / Q000494:pharmacology; D008969:Molecular Sequence Data; D016296:Mutagenesis; D009153:Mutagens / Q000494:pharmacology; D011506:Proteins / Q000235:genetics*; D011995:Recombination, Genetic; D012377:Rodentia / Q000235:genetics; D017384:Sequence Deletion; D017386:Sequence Homology, Amino Acid; D014162:Transfection; D014983:Xeroderma Pigmentosum / Q000209:etiology / Q000235:genetics
D018076:DNA, Complementary; D004268:DNA-Binding Proteins; D009153:Mutagens; D011506:Proteins; D016685:Mitomycin; C071447:ERCC1 protein, human; D004720:Endonucleases; D002945:Cisplatin