Stable maintenance of genetic information requires chromosome segregation to occur with high accuracy. Anaphase is triggered when ring-shaped cohesin is cleaved by separase, a protease regulated by association with its inhibitor securin. Dispensability of vertebrate securin strongly suggests additional means of separase regulation. Indeed, sister chromatid separation but not securin degradation...

A hypothesis to explain the maternal age-dependent increase in formation of aneuploid eggs is deterioration of chromosome cohesion. Although several lines of evidence are consistent with this hypothesis, whether cohesion is actually reduced in naturally aged oocytes has not been directly tested by any experimental perturbation. To directly target cohesion, we increased the activity of separase,...

Budding yeast securin/Pds1p, an inhibitor of the anaphase activator separase/Esp1p, is involved in several checkpoint pathways and in promoting Esp1p's nuclear localization. Using a modified synthetic genetic array (SGA) screen for genes that become essential in the absence of Pds1p, we uncovered roles for uncharacterized genes in cell cycle processes, including Esp1p activation.

We have previously isolated the hpttg proto-oncogene, which is expressed in normal tissues containing proliferating cells and in several kinds of tumors. In fact, expression of hPTTG correlates with cell proliferation in a cell cycle-dependent manner. Recently it was reported that PTTG is a vertebrate analog of the yeast securins Pds1 and Cut2, which are involved in sister chromatid separation....

OBJECTIVE We investigated the effects of small interference RNA (siRNA) on the cell proliferation inhibition, sensitivity to radiotherapy effects and cell apoptosis. The siRNA used here was specific to the pituitary tumor transforming gene (PTTG). MATERIALS AND METHODS Vectors containing the specific functional siRNAs for PTTG were designed and constructed. Cells were divided into four groups...