An alpha-tubulin mutant demonstrates distinguishable functions among the spindle assembly checkpoint genes in Saccharomyces cerevisiae.
Cells expressing a mutant allele of alpha-tubulin, tub1-729, are cold sensitive and arrest as large-budded cells with microtubule defects. The cold sensitivity of tub1-729 is suppressed by extra copies of a subset of the mitotic checkpoint genes BUB1, BUB3, and MPS1, but not MAD1, MAD2, and MAD3. This suppression by checkpoint genes does not depend upon their role in the MAD2-dependent spindle assembly checkpoint. In addition, BUB1 requires an intact kinase domain as well as Bub3p to suppress tub1-729. The data suggest that tub1-729 cells are defective in microtubule-kinetochore attachments and that the products of specific checkpoint genes can act either directly or indirectly to affect these attachments.
Abruzzi
Katharine C
KC
Department of Biology and Center for Cancer Research, Massachusetts Institute of Technology, Cambridge, MA 02139, USA.
Magendantz
Margaret
M
Solomon
Frank
F
D000483:Alleles; D001483:Base Sequence; D015825:Chromosomes, Fungal / Q000235:genetics; D017931:DNA Primers; D005800:Genes, Fungal; D005838:Genotype; D008938:Mitosis / Q000235:genetics; D010957:Plasmids; D016133:Polymerase Chain Reaction; D012441:Saccharomyces cerevisiae / Q000166:cytology / Q000235:genetics* / Q000254:growth & development; D008941:Spindle Apparatus / Q000235:genetics*; D013696:Temperature; D014404:Tubulin / Q000235:genetics*
D017931:DNA Primers; D014404:Tubulin