Involvement of XXXX -dependent damage checkpoint control in arrest of cell cycle, induction of cell death, and chromosome instability caused by defects in origin recognition complex in @entity375 .

@entity58617 @entity58618 @entity20087 @entity1167 @entity2008 @entity375
Perturbation of origin firing in chromosome replication is a possible cause of spontaneous chromosome instability in multireplicon organisms. Here, we show that @entity2008 , including aneuploidy and chromosome rearrangement, were significantly increased in @entity375 diploid cells with defects in the origin recognition complex. The cell cycle of @entity58617 -4/ @entity58617 -4 temperature-sensitive mutant was arrested at the G2/M boundary, after several rounds of cell division at the restrictive temperature. However, prolonged incubation of the mutant cells at 37 degrees C led to abrogation of @entity1167 , and simultaneously the cells started to lose viability. A sharp increase in chromosome instability followed the abrogation of @entity1167 . In @entity58617 -4/ @entity58617 -4 rad9delta/rad9delta diploid cells grown at 37 degrees C, @entity1167 and induction of cell death were suppressed, while chromosome instability was synergistically augmented. These findings indicated that DNA lesions caused by a defect in @entity58617 function trigger the @entity20087 -dependent checkpoint control, which ensures genomic integrity either by stopping the cell cycle progress until lesion repair, or by inducing cell death when the lesion is not properly repaired. At semirestrictive temperatures, @entity58618 -1/ @entity58618 -1 diploid cells demonstrated @entity1167 and loss of cell viability, both of which require @entity20087 -dependent checkpoint control. However, chromosome instability was not induced in @entity58618 -1/ @entity58618 -1 cells, even in the absence of the checkpoint control. These data suggest that once cells lose the damage checkpoint control, perturbation of origin firing can be tolerated by the cells. Furthermore, although a reduction in origin-firing capacity does not necessarily initiate chromosome instability, the @entity58617 possesses a unique function, the loss of which induces instability in the chromosome.
