K. Yamagata et al., BLOOMS-AND-WERNERS-SYNDROME GENES SUPPRESS HYPERRECOMBINATION IN YEAST SGS1 MUTANT - IMPLICATION FOR GENOMIC INSTABILITY IN HUMAN-DISEASES, Proceedings of the National Academy of Sciences of the United Statesof America, 95(15), 1998, pp. 8733-8738
Bloom's syndrome (BS) and Werner's syndrome (WS) are genetic disorders
in which an increased rate of chromosomal aberration is detected. The
genes responsible for these diseases, BLM and WRN, have been found to
be homologs of Escherichia coli recQ and Saccharomyces cerevisiae SGS
1 genes. Here we show that yeast Sgs1 helicase acts as a suppressor of
illegitimate recombination through homologous recombination and that
human BLM and WRN helicases can suppress the increased homologous and
illegitimate recombinations in the S. cerevisiae sgs1 mutant. The resu
lts imply a role of BLM and WRN helicases to control genomic stability
in human cells. Similar to Sgs1 helicase, BLM helicase suppressed the
cell growth in the top3 sgs1 mutation background and restored the inc
reased sensitivity of the sgs1 mutant to hydroxyurea, but the WRN heli
case did not, We discussed differential roles of BLM and WRN helicases
in human cells. BLM- and WRN-bearing yeasts provide new useful models
to investigate human BS and WS diseases.