title: A novel human AP endonuclease with conserved zinc-finger-like motifs involved in DNA strand break responses.
abstract: DNA damage causes genome instability and cell death, but many of the cellular responses to DNA damage still remain elusive. We here report a human protein, PALF (PNK and APTX-like FHA protein), with an FHA (forkhead-associated) domain and novel zinc-finger-like CYR (cysteine-tyrosine-arginine) motifs that are involved in responses to DNA damage. We found that the CYR motif is widely distributed among DNA repair proteins of higher eukaryotes, and that PALF, as well as a Drosophila protein with tandem CYR motifs, has endo- and exonuclease activities against abasic site and other types of base damage. PALF accumulates rapidly at single-strand breaks in a poly(ADP-ribose) polymerase 1 (PARP1)-dependent manner in human cells. Indeed, PALF interacts directly with PARP1 and is required for its activation and for cellular resistance to methyl-methane sulfonate. PALF also interacts directly with KU86, LIGASEIV and phosphorylated XRCC4 proteins and possesses endo/exonuclease activity at protruding DNA ends. Various treatments that produce double-strand breaks induce formation of PALF foci, which fully coincide with gammaH2AX foci. Thus, PALF and the CYR motif may play important roles in DNA repair of higher eukaryotes.
authors: Department of Molecular Genetics, Institute of Development, Aging and Cancer, Tohoku University, Aobaku, Sendai, Japan.
authors: Shin-ichiro
authors: S
authors: Kanno
authors: Hiroyuki
authors: H
authors: Kuzuoka
authors: Shigeru
authors: S
authors: Sasao
authors: Zehui
authors: Z
authors: Hong
authors: Li
authors: L
authors: Lan
authors: Satoshi
authors: S
authors: Nakajima
authors: Akira
authors: A
authors: Yasui
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D034961:Antigens, Nuclear; D045744:Cell Line, Tumor; D002853:Chromatography, Liquid; D004249:DNA Damage; D000072481:DNA Ligase ATP; D011088:DNA Ligases / Q000378:metabolism; D004260:DNA Repair / Q000502:physiology*; D043603:DNA-(Apurinic or Apyrimidinic Site) Lyase / Q000235:genetics / Q000378:metabolism*; D004268:DNA-Binding Proteins / Q000378:metabolism; D005455:Fluorescent Antibody Technique; D006801:Humans; D000072200:Ku Autoantigen; D013058:Mass Spectrometry; D051379:Mice; D018345:Mice, Knockout; D008969:Molecular Sequence Data; D009841:Oligonucleotides; D000071137:Poly (ADP-Ribose) Polymerase-1; D011065:Poly(ADP-ribose) Polymerases / Q000378:metabolism*; D000075223:Poly-ADP-Ribose Binding Proteins; D017434:Protein Structure, Tertiary; D034741:RNA, Small Interfering / Q000235:genetics; D016415:Sequence Alignment; D016335:Zinc Fingers / Q000235:genetics
chemical_list: D034961:Antigens, Nuclear; D004268:DNA-Binding Proteins; D009841:Oligonucleotides; D000075223:Poly-ADP-Ribose Binding Proteins; D034741:RNA, Small Interfering; C101467:XRCC4 protein, human; C499320:PARP1 protein, human; D000071137:Poly (ADP-Ribose) Polymerase-1; D011065:Poly(ADP-ribose) Polymerases; C000606512:Xrcc5 protein, mouse; C000606509:Xrcc6 protein, human; C000606510:Xrcc6 protein, mouse; D000072200:Ku Autoantigen; C520557:APLF protein, human; D043603:DNA-(Apurinic or Apyrimidinic Site) Lyase; D011088:DNA Ligases; D000072481:DNA Ligase ATP