Abstract IA14: Mechanisms of the ATR-dependent replication stress response

Replication stress can be caused by DNA damage, difficult to replicate DNA sequences, collisions between replication and transcriptional machineries, and aberrations in the replication timing or other regulatory mechanisms. Cancer cells often have elevated levels of replication stress driven by oncogenes. Replication stress response pathways are important in these contexts to allow cells to complete replication, maintain genome stability, and remain viable. Drugs that increase the replication stress burden or inactivate components of the replication stress response pathway can be useful as cancer therapeutics. For example, inhibitors of the replication checkpoint kinase ATR are currently being tested in clinical trials. To better understand how replication stress response pathways operate, we have taken both genetic and proteomic approaches. These approaches include purifying active and stressed replication fork proteomes using isolation of proteins on nascent DNA (iPOND). iPOND can monitor changes in the replication fork proteome and when combined with mass spectrometry provides an unbiased analysis. These approaches have allowed us characterize the consequences of replication stress and functions of ATR. For example, we found that ATR does not regulate the stability of the replisome itself in response to stress, but it does direct the action of a number of fork remodeling enzymes including SMARCAL1 that act to protect and repair damaged forks. In addition, iPOND identified ...
Source: Molecular Cancer Research - Category: Cancer & Oncology Authors: Tags: Replication Stress: Oral Presentations - Invited Abstracts Source Type: research