title: Nnf1p, Dsn1p, Mtw1p, and Nsl1p: a new group of proteins important for chromosome segregation in Saccharomyces cerevisiae.
abstract: Previously, antibodies were raised against a nuclear envelope-enriched fraction of yeast, and the essential gene NNF1 was cloned by reverse genetics. Here it is shown that the conditional nnf1-17 mutant has decreased stability of a minichromosome in addition to mitotic spindle defects. I have identified the novel essential genes DSN1, DSN3, and NSL1 through genetic interactions with nnf1-17. Dsn3p was found to be equivalent to the kinetochore protein Mtw1p. By indirect immunofluorescence, all four proteins, Nnf1p, Mtw1p, Dsn1p, and Nsl1p, colocalize and are found in the region of the spindle poles. Based on the colocalization of these four proteins, the minichromosome instability and the spindle defects seen in nnf1 mutants, I propose that Nnf1p is part of a new group of proteins necessary for chromosome segregation.
authors.affiliation: Department of Biological Sciences, Columbia University, New York, New York 10027, USA. ghia.euskirchen@yale.edu
authors.forename: Ghia M
authors.initials: GM
authors.lastname: Euskirchen
mesh_terms: D000483:Alleles; D018797:Cell Cycle Proteins / Q000235:genetics / Q000378:metabolism / Q000502:physiology; D002478:Cells, Cultured; D002868:Chromosomal Proteins, Non-Histone / Q000235:genetics / Q000378:metabolism / Q000502:physiology; D020090:Chromosome Segregation; D019976:Cloning, Organism / Q000379:methods; D005434:Flow Cytometry; D020043:Genes, Essential; D005800:Genes, Fungal; D018386:Kinetochores; D008938:Mitosis / Q000235:genetics; D008957:Models, Genetic; D009154:Mutation; D010957:Plasmids / Q000235:genetics; D012441:Saccharomyces cerevisiae / Q000235:genetics* / Q000378:metabolism; D029701:Saccharomyces cerevisiae Proteins / Q000145:classification / Q000235:genetics / Q000378:metabolism / Q000502:physiology*; D013696:Temperature
chemical_list: D018797:Cell Cycle Proteins; D002868:Chromosomal Proteins, Non-Histone; C470829:Dsn1 protein, S cerevisiae; C120362:MTW1 protein, S cerevisiae; C108276:NNF1 protein, S cerevisiae; C470828:Nsl1 protein, S cerevisiae; D029701:Saccharomyces cerevisiae Proteins