PerspectiveCELL CYCLE

The Difficulty in Separating Sisters

Science  16 Jul 1999:
Vol. 285, Issue 5426, pp. 344-345
DOI: 10.1126/science.285.5426.344b

You are currently viewing the summary.

View Full Text

Via your Institution

Log in through your institution

Log in through your institution


The separation of the tightly associated sister chromatids during the anaphase step of cell division is an intricately orchestrated event. Orr-Weaver, in her Perspective, discusses new findings by Zou et al. in this issue that reveal the underlying molecular machinery involved. A protein called a separin, Esp1, is held in check by a securin, which in humans turns out to be the protein encoded by PTTG, an oncogene. Once released from its complex with securin, Esp1 cleaves off a subunit from the cohesin complex that is responsible for keeping the sister chromatids together. Orr-Weaver points out the intriguing possibility that in some tumors, mutation of PTTG may result in abnormal separation of sister chromatids and chromosome instability.