Molecular analysis of the dhp1+ gene of Schizosaccharomyces pombe: an essential gene that has homology to the DST2 and RAT1 genes of Saccharomyces cerevisiae.
The DST2 gene of Saccharomyces cerevisiae encodes a DNA strand exchange protein, STP beta, which is required for homologous recombination in both mitotic or meiotic cells. We have cloned a DST2-related gene from the fission yeast Schizosaccharomyces pombe and designated it dhp1+. The nucleotide sequence of dhp1+ revealed an open reading frame encoding a protein composed of 991 amino acids. The predicted amino acid sequence was significantly homologous to the S. cerevisiae STP beta, but lacked the carboxy-terminal sequence present in STP beta. Furthermore, dhp1+ shows greater homology to RAT1/HKE1, a gene which is involved in RNA trafficking and processing. Genetic experiments showed that dhp1+ on an S. cerevisiae expression vector could rescue both the defects of the S. cerevisiae DST2 disruptant, slow growth rate and a sporulation defect, and the lethality of the S. cerevisiae rat1ts mutation. This implies the functional similarity of dhp1+ to both DST2 and RAT1. However unlike DST2, dhp1+ is an essential gene for cell growth in S. pombe, suggesting that dhp1+ is not the true homologue of DST2 but rather of RAT1 in S. pombe. The possible roles of dhp1+ in recombination and cell growth in S. pombe are discussed.
Sugano
S
S
Department of Molecular Biology, University of Tokyo, Japan.
Shobuike
T
T
Takeda
T
T
Sugino
A
A
Ikeda
H
H
D000595:Amino Acid Sequence; D001483:Base Sequence; D003001:Cloning, Molecular; D004271:DNA, Fungal; D005095:Exoribonucleases; D005656:Fungal Proteins / Q000235:genetics*; D005800:Genes, Fungal; D005816:Genetic Complementation Test; D008969:Molecular Sequence Data; D009713:Nucleotidyltransferases / Q000235:genetics*; D016366:Open Reading Frames; D015183:Restriction Mapping; D012441:Saccharomyces cerevisiae / Q000235:genetics*; D029701:Saccharomyces cerevisiae Proteins; D012568:Schizosaccharomyces / Q000235:genetics*; D029702:Schizosaccharomyces pombe Proteins; D017386:Sequence Homology, Amino Acid; D015534:Trans-Activators / Q000235:genetics*
D004271:DNA, Fungal; D005095:Exoribonucleases; D005656:Fungal Proteins; D009713:Nucleotidyltransferases; D029701:Saccharomyces cerevisiae Proteins; D029702:Schizosaccharomyces pombe Proteins; D015534:Trans-Activators; C075577:RAT1 protein, S cerevisiae; C087281:dhp1 protein, S pombe; C068398:XRN1 protein, S cerevisiae