Abstract
The efficient assembly of newly replicated and repaired DNA into chromatin is essential for proper genome function. Based on genetic studies in Saccharomyces cerevisiae, the histone chaperone anti-silencing function 1 (Asf1) has been implicated in the DNA repair response. Here, the human homologs are shown to function synergistically with human CAF-1 to assemble nucleosomes during nucleotide excision repair in vitro. Furthermore, we demonstrate that hAsf1 proteins can interact directly with the p60 subunit of hCAF-1. In contrast to hCAF-1 p60, the nuclear hAsf1 proteins are not significantly associated with chromatin in cells before or after the induction of DNA damage, nor specifically recruited to damaged DNA during repair in a bead-linked DNA assay. A model is proposed in which the synergism between hAsf1 and CAF-1 for nucleosome formation during DNA repair is achieved through a transient physical interaction allowing histone delivery from Asf1 to CAF-1.