Nuclear retention of ATM at sites of DNA double strand breaks.
The ATM protein kinase mediates a rapid induction of cellular responses to DNA double strand breaks (DSBs). ATM kinase activity is enhanced immediately after exposure of cells to DSB-inducing agents, but no changes in its amount or subcellular location following that activation have been reported. We speculated that some of the ATM molecules associate with sites of DSBs, while the rest of the nuclear ATM pool remains in the nucleoplasm, masking detection of the damage-associated ATM fraction. Using detergent extraction to remove nucleoplasmic proteins, we show here that immediately following induction of DSBs, a fraction of the ATM pool becomes resistant to extraction and is detected in nuclear aggregates. Colocalization of the retained ATM with the phosphorylated form of histone H2AX (gamma-H2AX) and with foci of the Nbs1 protein suggests that ATM associates with sites of DSBs. The striking correlation between the appearance of retained ATM and of gamma-H2AX, and the rapid association of a fraction of ATM with gamma-H2AX foci, are consistent with a major role for ATM in the early detection of DSBs and subsequent induction of cellular responses.
Andegeko
Y
Y
David and Inez Myers Laboratory for Genetic Research, Department of Human Genetics and Molecular Medicine, Interdepartmental Core Facility, Sackler School of Medicine, Tel Aviv University, Ramat Aviv 69978, Israel.
Moyal
L
L
Mittelman
L
L
Tsarfaty
I
I
Shiloh
Y
Y
Rotman
G
G
D000730:Androstadienes / Q000494:pharmacology; D064007:Ataxia Telangiectasia Mutated Proteins; D018797:Cell Cycle Proteins; D002467:Cell Nucleus / Q000201:enzymology*; D004249:DNA Damage; D004268:DNA-Binding Proteins; D003902:Detergents; D004791:Enzyme Inhibitors / Q000494:pharmacology; D005455:Fluorescent Antibody Technique; D006367:HeLa Cells; D006801:Humans; D007700:Kinetics; D009153:Mutagens / Q000494:pharmacology; D017346:Protein Serine-Threonine Kinases / Q000037:antagonists & inhibitors / Q000378:metabolism*; D025521:Tumor Suppressor Proteins; D000077191:Wortmannin
D000730:Androstadienes; D018797:Cell Cycle Proteins; D004268:DNA-Binding Proteins; D003902:Detergents; D004791:Enzyme Inhibitors; D009153:Mutagens; D025521:Tumor Suppressor Proteins; C576324:ATM protein, human; D064007:Ataxia Telangiectasia Mutated Proteins; D017346:Protein Serine-Threonine Kinases; D000077191:Wortmannin