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.
Fleig
U
U
Institut fur Mikrobiologie und Molekularbiologie, Universitat Giessen, Germany. Ursula. Fleig@bio.uni-giessen.de
Sen-Gupta
M
M
Hegemann
J H
JH
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