Bub1b-IN

Bub1, a mitotic checkpoint gene first identified in yeast, ensures proper chromosome segregation by delaying anaphase until chromosomes are properly aligned on the mitotic spindle. Mutations in the mitotic spindle assembly checkpoint genes, like yeast Bub1, cause cells to exit mitosis without proper chromosome attachment/alignment, resulting in aneuploidy. Aneuploidy is a form of genetic instability involved in cancer. Recently, a novel homologue of the murine Bub1 gene has been identified and named Bub1b. The yeast mitotic checkpoint pathway is unresolved, but the mammalian pathway remains even less clear. It is important to investigate the role of the Bub1 genes in the mammalian checkpoint as they have been implicated in carcinogenesis, namely colon carcinomas. The aneuploidy and chromosome instability characterizing some tumors is thought to be caused by mutations in Bub1.