A knockout screen for protein kinases required for the proper meiotic segregation of chromosomes in the fission yeast Schizosaccharomyces pombe.
The reduction of chromosome number during meiosis is achieved by two successive rounds of chromosome segregation after just single round of DNA replication. To identify novel proteins required for the proper segregation of chromosomes during meiosis, we analyzed the consequences of deleting Schizosaccharomyces pombe genes predicted to encode protein kinases that are not essential for cell viability. We show that Mph1, a member of the Mps1 family of spindle assembly checkpoint kinases, is required to prevent meiosis I homolog non-disjunction. We also provide evidence for a novel function of Spo4, the fission yeast ortholog of Dbf4-dependent Cdc7 kinase, in regulating the length of anaphase II spindles. In the absence of Spo4, abnormally elongated anaphase II spindles frequently overlap and thus destroy the linear order of nuclei in the ascus. Our observation that the spo4Δ mutant phenotype can be partially suppressed by inhibiting Cdc2-as suggests that dysregulation of the activity of this cyclin-dependent kinase may cause abnormal elongation of anaphase II spindles in spo4Δ mutant cells.
Max F. Perutz Laboratories, Department of Chromosome Biology, University of Vienna, Vienna, Austria.
Ines
I
Kovacikova
Silvia
S
Polakova
Zsigmond
Z
Benko
Lubos
L
Cipak
Lijuan
L
Zhang
Cornelia
C
Rumpf
Eva
E
Miadokova
Juraj
J
Gregan
D016203:CDC2 Protein Kinase / Q000037:antagonists & inhibitors / Q000235:genetics / Q000378:metabolism; D018797:Cell Cycle Proteins / Q000172:deficiency / Q000235:genetics; D002467:Cell Nucleus / Q000235:genetics / Q000378:metabolism; D015825:Chromosomes, Fungal / Q000235:genetics* / Q000648:ultrastructure; D004261:DNA Replication; D015966:Gene Expression Regulation, Fungal; D055786:Gene Knockout Techniques; D005838:Genotype; D008540:Meiosis / Q000235:genetics*; D009630:Nondisjunction, Genetic; D010641:Phenotype; D010957:Plasmids / Q000235:genetics; D011494:Protein Kinases / Q000235:genetics / Q000378:metabolism; D017346:Protein Serine-Threonine Kinases / Q000172:deficiency / Q000235:genetics; D012568:Schizosaccharomyces / Q000235:genetics* / Q000378:metabolism / Q000648:ultrastructure; D029702:Schizosaccharomyces pombe Proteins / Q000037:antagonists & inhibitors / Q000235:genetics / Q000378:metabolism
D018797:Cell Cycle Proteins; D029702:Schizosaccharomyces pombe Proteins; C570446:Mph1 protein, S pombe; D011494:Protein Kinases; C443677:Spo4 protein, S pombe; D017346:Protein Serine-Threonine Kinases; D016203:CDC2 Protein Kinase; C469447:cdc2 protein, S pombe
anaphase; chromosome segregation; fission yeast; meiosis; protein kinase; spindle