Human and mouse homologs of the Saccharomyces cerevisiae RAD54 DNA repair gene: evidence for functional conservation.
BACKGROUND
Homologous recombination is of eminent importance both in germ cells, to generate genetic diversity during meiosis, and in somatic cells, to safeguard DNA from genotoxic damage. The genetically well-defined RAD52 pathway is required for these processes in the yeast Saccharomyces cerevisiae. Genes similar to those in the RAD52 group have been identified in mammals. It is not known whether this conservation of primary sequence extends to conservation of function.


RESULTS
Here we report the isolation of cDNAs encoding a human and a mouse homolog of RAD54. The human (hHR54) and mouse (mHR54) proteins were 48% identical to Rad54 and belonged to the SNF2/SW12 family, which is characterized by amino-acid motifs found in DNA-dependent ATPases. The hHR54 gene was mapped to chromosome 1p32, and the hHR54 protein was located in the nucleus. We found that the levels of hHR54 mRNA increased in late G1 phase, as has been found for RAD54 mRNA. The level of mHR54 mRNA was elevated in organs of germ cell and lymphoid development and increased mHR54 expression correlated with the meiotic phase of spermatogenesis. The hHR54 cDNA could partially complement the methyl methanesulfonate-sensitive phenotype of S. cerevisiae rad54 delta cells.


CONCLUSIONS
The tissue-specific expression of mHR54 is consistent with a role for the gene in recombination. The complementation experiments show that the DNA repair function of Rad54 is conserved from yeast to humans. Our findings underscore the fundamental importance of DNA repair pathways: even though they are complex and involve multiple proteins, they seem to be functionally conserved throughout the eukaryotic kingdom.
Kanaar
R
R
Department of Cell Biology and Genetics, Erasmus University Rotterdam, The Netherlands. knaar@gen.fgg.eur.nl
Troelstra
C
C
Swagemakers
S M
SM
Essers
J
J
Smit
B
B
Franssen
J H
JH
Pastink
A
A
Bezzubova
O Y
OY
Buerstedde
J M
JM
Clever
B
B
Heyer
W D
WD
Hoeijmakers
J H
JH
D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D019556:COS Cells; D002874:Chromosome Mapping; D017124:Conserved Sequence; D004265:DNA Helicases; D004260:DNA Repair; D045643:DNA Repair Enzymes; D018076:DNA, Complementary; D004268:DNA-Binding Proteins; D005656:Fungal Proteins / Q000235:genetics; D015870:Gene Expression; D005816:Genetic Complementation Test; D006367:HeLa Cells; D006801:Humans; D051379:Mice; D008969:Molecular Sequence Data; D009687:Nuclear Proteins / Q000235:genetics* / Q000378:metabolism; D012441:Saccharomyces cerevisiae / Q000235:genetics / Q000378:metabolism; D029701:Saccharomyces cerevisiae Proteins; D017386:Sequence Homology, Amino Acid
D018076:DNA, Complementary; D004268:DNA-Binding Proteins; D005656:Fungal Proteins; D009687:Nuclear Proteins; D029701:Saccharomyces cerevisiae Proteins; C075468:RAD54 protein, S cerevisiae; D004265:DNA Helicases; C103532:RAD54L protein, human; C103534:Rad54l protein, mouse; D045643:DNA Repair Enzymes