Chromatin assembly factor 1

Chromatin assembly factor-1 (CAF-1) is a protein complex — including Chaf1a (p150), Chaf1b (p60), and p50 subunits — that assembles histone tetramers onto replicating DNA. CAF-1 functions as a histone chaperone that mediates the first step in nucleosome formation by tetramerizing and depositing newly synthesized histone H3/H4 onto DNA rapidly behind replication forks. Several studies have shown that the interaction between CAF-1 and PCNA, which stabilizes CAF-1 at replication forks, is important for CAF-1's role in nucleosome assembly
CAF-1 is required for the spatial organization and epigenetic marking of heterochromatin domains in pluripotent embryonic cells, creating a cellular memory of somatic cell identity during cellular differentiation.
Cells resembling 2-cell-stage mouse embryos (totipotent cells) can be induced in vitro through downregulation of the chromatin-assembly activity of CAF-1 in embryonic stem cells.