Fission yeast mal2+ is required for chromosome segregation.
By a screen designed to isolate new fission yeast genes required for chromosome segregation, we have identified mal2+. The conditionally lethal mal2-1 allele gives rise to increased loss of a nonessential minichromosome at the permissive temperature and leads to severe missegregation of the chromosomes at the nonpermissive temperature. Cloning by complementation and subsequent sequence analysis revealed that mal2 is a novel protein with a mass of 34 kDa. Cells containing a mal2 null allele were inviable, indicating that mal2+ is an essential gene. Fusion of mal2 protein to the green fluorescent protein (GFP) showed that mal2 was predominantly localized in the nucleus. Sensitivity to microtubule-destabilizing drugs and strong genetic interactions with alpha1-tubulin suggest an interaction of the mal2 protein with the microtubule system. Spindle formation and elongation were not detectably affected in the mal2-1 mutant as determined by indirect immunofluorescence. However, anomalous chromosome movement on the spindle leading to aberrant distribution of the chromosomal material was observed.
Institut fur Mikrobiologie und Molekularbiologie, Universitat Giessen, Germany. Ursula. Fleig@bio.uni-giessen.de
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D000483:Alleles; D000595:Amino Acid Sequence; D001483:Base Sequence; D015825:Chromosomes, Fungal; D017931:DNA Primers; D005020:Ethyl Methanesulfonate; D005800:Genes, Fungal; D005804:Genes, Lethal; D049452:Green Fluorescent Proteins; D008164:Luminescent Proteins / Q000096:biosynthesis; D008969:Molecular Sequence Data; D016296:Mutagenesis; D009687:Nuclear Proteins / Q000096:biosynthesis / Q000235:genetics*; D010641:Phenotype; D016133:Polymerase Chain Reaction; D011993:Recombinant Fusion Proteins / Q000096:biosynthesis; D012568:Schizosaccharomyces / Q000166:cytology / Q000235:genetics* / Q000254:growth & development; D029702:Schizosaccharomyces pombe Proteins
D017931:DNA Primers; D008164:Luminescent Proteins; C102110:Mal2 protein, S pombe; D009687:Nuclear Proteins; D011993:Recombinant Fusion Proteins; D029702:Schizosaccharomyces pombe Proteins; D049452:Green Fluorescent Proteins; D005020:Ethyl Methanesulfonate