The Role of Chk2 in Breast Cancer
Abstract
In the last progress report, I described our progress on the isolation of Chk2 mutant cells and their characterization. That aim is essentially completed. In the last year we have concentrated on Aim 2, which includes finding Chk2 associated proteins and potential Chk2 substrates. To identify Chk2 associated proteins, we took the FHA domain (Forked-Head Associated) of Chk2 which is known to be involved in protein-Protein interaction and produced it in E. coli as a GST fusion. We then went on to use this GST-FHA domain protein as an affinity column to purify associated proteins. In this way we identified a known DNA damage regulated protein 53BP1. We provide the data for this experiment below in the Body section. 53BP1 was originally identified through its ability to bind to the tumor suppressor protein p53 through 53BP1's C-terminal BRCT (Brcal carboxyl terminus) repeats (1,2) which are found in many DNA damage response proteins (3-8). 53BP1 responds to DNA double strand breaks (9-12), quickly relocalizing to discrete nuclear foci upon exposure to IR. These foci colocalize with those of the Mrel l/Nbsl/Rad50 complex and phosphorylated gamma-H2AX which are thought to facilitate recruitment of repair factors to damaged DNA (9-11). In response to IR, 53BP1 is phosphorylated in an ATM (ataxia telangiectasia mutated) dependent manner (10-12), but its role in the DNA damage response is unclear.
Document Details
- Document Type
- Technical Report
- Publication Date
- Apr 01, 2004
- Accession Number
- ADA425809
Entities
People
- Stephan J. Elledge
Organizations
- Baylor College of Medicine