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.
Department of Biology and Center for Cancer Research, Massachusetts Institute of Technology, Cambridge, MA 02139, USA.
Katharine C
KC
Abruzzi
Margaret
M
Magendantz
Frank
F
Solomon
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