Ataxia telangiectasia and Rad3 related (ATR)

Ataxia telangiectasia and Rad3 related (ATR) is a serine/threonine protein kinase that plays a central role in the DNA damage response (DDR), particularly during DNA replication and in response to DNA damage. It is a key sensor of single-stranded DNA associated with stalled replication forks or intermediates generated during base excision repair (BER) and double-strand break repair. Upon activation, ATR initiates checkpoint signaling cascades that halt cell cycle progression for damage assessment/repair and phosphorylates downstream effectors like Chk1. Inhibitors targeting ATR are being developed as potential cancer therapeutics, especially for tumors with defects in other DDR components.

Other names

Serine/threonine-protein kinase ATRFRAP-related protein 1FRP1

ATR inhibitors block the kinase activity of ATR, preventing the activation of downstream checkpoint signaling and DNA repair pathways, ultimately leading to cell death, especially in cells with other DDR defects.