A Truncated Form of the Human CAF-1 p150 Subunit Impairs the Maintenance of Transcriptional Gene Silencing in Mammalian Cells

• DOI: 10.1128/mcb.21.6.1953-1961.2001
• Publication Date: 2002-07-27T10:03:53Z
• Authors: Thierry Tchénio; Jean-François Cas...; Thierry Heidmann
• Keywords: Mammals; 0303 health sciences; DNA, Complementary; Transcription, Genetic; Chromosomal Proteins, Non-Histone; DNA Methylation; Chromatin; DNA-Binding Proteins; Chromatin Assembly Factor-1; Protein Subunits; 03 medical and health sciences; Genes, Reporter; Mutation; Azacitidine; Animals; Humans; Gene Silencing; Cells, Cultured; Transcription Factors

Chromatin assembly factor 1 (CAF-1) is a protein complex formed of three subunits, p150, p60, and p48, conserved from the yeast Saccharomyces cerevisiae to humans, which can promote nucleosome onto newly replicated DNA.In S. cerevisiae, deletion genes encoding any CAF-1 subunits (cac⌬ mutants), although nonlethal, results in silencing defect packaged into heterochromatin.Here we report on mammalian cell model that devised monitor gene its reversal quantitative manner.This relies use line stably transfected with reporter silenced state.Reversal was achieved upon treatment cells 5-azacytidine, resulted demethylation copies.We show expression cDNA for human p150 subunit harboring 5 truncations, but not full-length subunit, increases by more than 500-fold frequency at transcriptional copies reversed these cells.Reversal dependent truncated protein, possibly acting as dominant negative mutant wild-type CAF-1, associated alterations chromatin structure measured an endonuclease sensitivity assay detectable changes methylation status genes.These suggest role epigenetic control has been between mammals, despite lack DNA chromatin.