Novel Chk1 substrates have been identified

High-resolution mass spectrometry (HR-MS) has been used to identify novel checkpoint kinase Chk1 substrates, as well as their phosphorylation sites.

In a study published by Genome Biology 2011, scientists from the University of Cambridge and the University of Copenhagen sought to gain further insight into the role of Chk1 and how it controls its functions.

According to the report, Chk1 has an essential role in controlling processes such as DNA replication, mitosis and DNA-damage responses, however, how it does this remains unclear as few substrates have hitherto been identified.

"The approach used employed an analogue-sensitive mutant of Chk1 that can directly label substrates in cell extracts by it using a thio-phosphate-bearing ATP-analogue. Thus, we have identified 268 phosphorylation sites in 171 proteins," the scientists claimed.

This substantial set of substrates provides a key opportunity to study the previously unanticipated functions of Chk1, with the findings also likely to help with the future prediction of Chk1 target sites.