Figure 7.

Model for the formation and dynamics of Sgo1p chromatin domain. A. Sgo1p is first recruited to the centromeres via association with phosphorylated histone H2A (Pi). Centromere-bound Sgo1p then spreads to the nearby cohesin-occupied region. B. At the whole genome level, congregation of centromeres aligns the adjacent chromatin loops to form concentric rings (gradient yellow circle) that become the two terminals of the chromatin column. Prior to biorientation, Sgo1p (gradient red circle) resides on the centromere cluster and the first ring of chromatin loops. Poleward pulling from bipolar attachment stretches the centromeric and pericentric chromatin, resulting in a conformational change (gradient green circle) and evicting Sgo1p.