@article {1580, title = {Targeting Phosphopeptide Recognition by the Human BRCA1 Tandem BRCT Domain to Interrupt BRCA1-Dependent Signaling.}, journal = {Cell Chem Biol}, volume = {25}, year = {2018}, month = {2018 06 21}, pages = {677-690.e12}, abstract = {
Intracellular signals triggered by DNA breakage flow through proteins containing BRCT (BRCA1 C-terminal) domains. This family, comprising 23 conserved phosphopeptide-binding modules in man, is inaccessible to small-molecule chemical inhibitors. Here, we develop Bractoppin, a drug-like inhibitor of phosphopeptide recognition by the human BRCA1 tandem (t)BRCT domain, which selectively inhibits substrate binding with nanomolar potency in\ vitro. Structure-activity exploration suggests that Bractoppin engages BRCA1 tBRCT residues recognizing pSer in the consensus motif, pSer-Pro-Thr-Phe, plus an abutting hydrophobic pocket that is distinct in structurally related BRCT domains, conferring selectivity. In cells, Bractoppin inhibits substrate recognition detected by F{\"o}rster resonance energy transfer, and diminishes BRCA1 recruitment to DNA breaks, in turn suppressing damage-induced G2 arrest and assembly of the recombinase, RAD51. But damage-induced MDC1 recruitment, single-stranded DNA (ssDNA) generation, and TOPBP1 recruitment remain unaffected. Thus, an inhibitor of phosphopeptide recognition selectively interrupts BRCA1 tBRCT-dependent signals evoked by DNA damage.
}, issn = {2451-9448}, doi = {10.1016/j.chembiol.2018.02.012}, author = {Periasamy, Jayaprakash and Kurdekar, Vadiraj and Jasti, Subbarao and Nijaguna, Mamatha B and Boggaram, Sanjana and Hurakadli, Manjunath A and Raina, Dhruv and Kurup, Lokavya Meenakshi and Chintha, Chetan and Manjunath, Kavyashree and Goyal, Aneesh and Sadasivam, Gayathri and Bharatham, Kavitha and Padigaru, Muralidhara and Potluri, Vijay and Venkitaraman, Ashok R} }