Checkpoint Signals

Seeking out Single-Stranded DNA

Science's STKE  10 Jun 2003:
Vol. 2003, Issue 186, pp. tw222-TW222
DOI: 10.1126/stke.2003.186.tw222

The checkpoint signals that cells generate in response to DNA damage are mediated by the ATR protein kinase, which functions in a complex with the ATRIP protein. Zou and Elledge (see the Perspective by Carr) found that the ATR-ATRIP complex was not recruited to sites of DNA damage in cells that lacked replication protein A (RPA). Although RPA functions in processes such as replication and recombination, it also appears to initiate the checkpoint signal by binding to single-stranded DNA and then interacting with the ATR-ATRIP complex, which phosphorylates substrate proteins at the damage site.

L. Zou, S. J. Elledge, Sensing DNA damage through ATRIP recognition of RPA-ssDNA complexes, Science 300, 1542-1548 (2003). [Abstract] [Full Text]

A. M. Carr , Beginning at the end, Science 300, 1512-1513 (2003). [Summary] [Full Text]