title: The PARP3- and ATM-dependent phosphorylation of APLF facilitates DNA double-strand break repair.
abstract: APLF is a forkhead associated-containing protein with poly(ADP-ribose)-binding zinc finger (PBZ) domains, which undergoes ionizing radiation (IR)-induced and Ataxia-Telangiectasia Mutated (ATM)-dependent phosphorylation at serine-116 (Ser(116)). Here, we demonstrate that the phosphorylation of APLF at Ser(116) in human U2OS cells by ATM is dependent on poly(ADP-ribose) polymerase 3 (PARP3) levels and the APLF PBZ domains. The interaction of APLF at sites of DNA damage was diminished by the single substitution of APLF Ser(116) to alanine, and the cellular depletion or chemical inhibition of ATM or PARP3 also altered the level of accumulation of APLF at sites of laser-induced DNA damage and impaired the accumulation of Ser(116)-phosphorylated APLF at IR-induced γH2AX foci in human cells. The data further suggest that ATM and PARP3 participate in a common signalling pathway to facilitate APLF-Ser(116) phosphorylation, which, in turn, appears to be required for efficient DNA double-strand break repair kinetics and cell survival following IR. Collectively, these findings provide a more detailed understanding of the molecular pathway that leads to the phosphorylation of APLF following DNA damage and suggest that Ser(116)-APLF phosphorylation facilitates APLF-dependent double-strand break repair.
authors: Division of Signalling Biology, Ontario Cancer Institute (University Health Network), 610 University Avenue, Toronto, Ontario M5G 2M9, Canada.
authors: Amanda L
authors: AL
authors: Fenton
authors: Purnata
authors: P
authors: Shirodkar
authors: Chloe J
authors: CJ
authors: Macrae
authors: Li
authors: L
authors: Meng
authors: C Anne
authors: CA
authors: Koch
mesh_terms: D064007:Ataxia Telangiectasia Mutated Proteins; D018797:Cell Cycle Proteins / Q000037:antagonists & inhibitors / Q000378:metabolism*; D002460:Cell Line; D053903:DNA Breaks, Double-Stranded; D004260:DNA Repair; D043603:DNA-(Apurinic or Apyrimidinic Site) Lyase / Q000737:chemistry / Q000378:metabolism*; D004268:DNA-Binding Proteins / Q000037:antagonists & inhibitors / Q000378:metabolism*; D007834:Lasers; D010766:Phosphorylation; D011065:Poly(ADP-ribose) Polymerases / Q000378:metabolism*; D000075223:Poly-ADP-Ribose Binding Proteins; D017346:Protein Serine-Threonine Kinases / Q000037:antagonists & inhibitors / Q000378:metabolism*; D017434:Protein Structure, Tertiary; D011836:Radiation Tolerance; D011839:Radiation, Ionizing; D012694:Serine / Q000378:metabolism; D025521:Tumor Suppressor Proteins / Q000037:antagonists & inhibitors / Q000378:metabolism*
chemical_list: D018797:Cell Cycle Proteins; D004268:DNA-Binding Proteins; D000075223:Poly-ADP-Ribose Binding Proteins; D025521:Tumor Suppressor Proteins; D012694:Serine; C480979:PARP3 protein, human; D011065:Poly(ADP-ribose) Polymerases; C576324:ATM protein, human; D064007:Ataxia Telangiectasia Mutated Proteins; D017346:Protein Serine-Threonine Kinases; C520557:APLF protein, human; D043603:DNA-(Apurinic or Apyrimidinic Site) Lyase