Date of Graduation


Document Type

Dissertation (PhD)

Program Affiliation

Genes and Development

Degree Name

Doctor of Philosophy (PhD)

Advisor/Committee Chair

Sharon Y.R. Dent, Ph.D.

Committee Member

Mark T. Bedford, Ph.D.

Committee Member

Jill Schumacher, Ph.D.

Committee Member

Xiaobing Shi, Ph.D.

Committee Member

Xuetong Shen, Ph.D.


Histone H3K4 methylation is conserved across species and is associated with active transcription. By using Saccharomyces cerevisiae, we found histone H3K4 methylation has a previously unknown role in regulating mitosis through the Spindle Assembly Checkpoint. The Spindle Assembly Checkpoint ensures duplicated chromosomes are segregated correctly and each daughter cell receives one full copy of the genome. Our data show SET1 mutants and histone H3K4 mutants display a resistance to the mitotic poison, benomyl. Moreover methylated histone H3 directly binds to Spindle Assembly Checkpoint proteins Bub3 and Mad2 as well as the activator of the Anaphase Promoting Complex (APC) protein Cdc20. MAD2 encodes a HORMA domain, which I identify as a novel histone binding motif. Mad2 maintains two differing conformations, closed Mad2 (C-Mad2) and open Mad2 (O-Mad2). We find C-Mad2 increases the Mad2-H3 interaction. In addition, O-Mad2 limits the H3-Mad2 interaction. Further analysis, shows C-Mad2 can bind to all unmodified, mono-, di-, and tri-methylated H3K4 while O-Mad2 loses H3 binding ability when H3K4 is di- or tri-methylated. Here we show H3K4 methylation inhibits the Spindle Assembly Checkpoint from correctly deactivating after cell cycle arrest by binding C-Mad2.


histone H3, HORMA domain, Mad2, Spindle Assembly Checkpoint, Lysine Methylation, H3K4 methylation