APLF (C2orf13) is a novel component of poly(ADP-ribose) signaling in mammalian cells

作者：Rulten Stuart L; Cortes Ledesma Felipe; Guo Liandi; Iles Natasha J; Caldecott Keith W^*

来源：Molecular and Cellular Biology, 2008, 28(14): 4620-4628.

DOI：10.1128/MCB.02243-07

APLF is a novel protein of unknown function that accumulates at sites of chromosomal DNA strand breakage via forkhead-associated (FHA) domain-mediated interactions with XRCC1 and XRCC4. APLF can also accumulate at sites of chromosomal DNA strand breaks independently of the FHA domain via an unidentified mechanism that requires a highly conserved C-terminal tandem zinc finger domain. Here, we show that the zinc finger domain binds tightly to poly (ADP-ribose), a polymeric posttranslational modification synthesized transiently at sites of chromosomal damage to accelerate DNA strand break repair reactions. Protein poly (ADP-ribosyl)ation is tightly regulated and defects in either its synthesis or degradation slow global rates of chromosomal single-strand break repair. Interestingly, APLF negatively affects poly(ADP-ribosyl)ation in vitro, and this activity is dependent on its capacity to bind the polymer. In addition, transient overexpression in human A549 cells of full-length APLF or a C-terminal fragment encoding the tandem zinc finger domain greatly suppresses the appearance of poly(ADP-ribose), in a zinc finger-dependent manner. We conclude that APLF can accumulate at sites of chromosomal damage via zinc finger-mediated binding to poly(ADP-ribose) and is a novel component of poly(ADP-ribose) signaling in mammalian cells.

• 出版日期2008-7