Characterization of the function of the NIN1 gene product of Saccharomyces cerevisiae.
The nin1-1 mutant has been isolated as a temperature-sensitive mutant whose nucleus arrested at G2 phase and eventually disintegrated upon temperature upshift. In this study, a genetic event occurring in the nin1-1 mutant was found to be a frameshift mutation, resulting in a truncated protein smaller than the wild-type Nin1 protein. We found new phenotypes associated with the nin1-1 mutation: (i) rates of mitotic recombination and chromosome/plasmid loss in the nin1-1 strain were higher than those in the wild-type strain, and (ii) the mutant was more sensitive to UV irradiation than the wild-type strain. We found dotted structures in the cytoplasm of the wild-type cells by indirect immunofluorescence microscopy using the anti-Nin1 antibody. Similar results were obtained when we analyzed the localization of Nin1-beta-galactosidase fusion protein formed in the cells expressing the NIN-lacZ fusion gene, which is active as NIN1, with anti-beta-galactosidase antibody. The subcellular fractionation method revealed that Nin1 protein was not localized in a particular fraction of the cell lysate.
Kominami
K
K
Department of Biology, Faculty of Science, University of Tokyo, Japan.
Toh-e
A
A
D000595:Amino Acid Sequence; D001483:Base Sequence; D002453:Cell Cycle / Q000235:genetics / Q000502:physiology; D003001:Cloning, Molecular; D003593:Cytoplasm / Q000378:metabolism; D004271:DNA, Fungal / Q000235:genetics; D016368:Frameshift Mutation; D005656:Fungal Proteins / Q000235:genetics* / Q000502:physiology*; D005800:Genes, Fungal; D008969:Molecular Sequence Data; D010641:Phenotype; D046988:Proteasome Endopeptidase Complex; D011993:Recombinant Fusion Proteins / Q000235:genetics / Q000378:metabolism; D011995:Recombination, Genetic; D012441:Saccharomyces cerevisiae / Q000235:genetics* / Q000502:physiology* / Q000528:radiation effects; D029701:Saccharomyces cerevisiae Proteins; D013347:Subcellular Fractions / Q000378:metabolism; D013696:Temperature; D014466:Ultraviolet Rays
D004271:DNA, Fungal; D005656:Fungal Proteins; C074096:RPN12 protein, S cerevisiae; D011993:Recombinant Fusion Proteins; D029701:Saccharomyces cerevisiae Proteins; D046988:Proteasome Endopeptidase Complex