Anti silencing function 1 (Asf1), a well conserved protein from yeast to human, acts as a histone chaperone and is predicted to participate in a variety of chromatin mediated cellular processes. To investigate the physiological role of vertebrate Asf1 in vivo, we generated a conditional Asf1 deficient mutant from chicken DT40 cells. Induction of Asf1-depletion resulted in the accumulation of cells in S phase with decreased DNA replication and increased mitotic aberrancy forming multipolar spindles, leading to cell death. In addition, nascent chromatin in Asf1 depleted cells showed increased nuclease sensitivity, indicating impaired nucleosome assembly during DNA replication. Complementation analyses revealed that the functional domain of Asf1 for cell viability was confined to the N-terminal core domain (1-155 amino acids) that is a binding platform for histones H3/H4, CAF-1p60 and HIRA, while Asf1 mutant proteins, abolishing binding abilities with both p60 and HIRA, exhibit no effect on viability. These results, together, indicate that the vertebrate Asf1 plays a crucial role in replication coupled chromatin assembly, cell cycle progression and cellular viability, and provides a clue of possible role in a CAF-1 and HIRA independent chromatin modulating process for cell proliferation.
|Evidence ID||Analyze ID||Interactor||Interactor Systematic Name||Interactor||Interactor Systematic Name||Type||Assay||Annotation||Action||Modification||Phenotype||Source||Reference||Note|
|Evidence ID||Analyze ID||Gene||Gene Systematic Name||Gene Ontology Term||Gene Ontology Term ID||Qualifier||Aspect||Method||Evidence||Source||Assigned On||Reference||Annotation Extension|
|Evidence ID||Analyze ID||Gene||Gene Systematic Name||Phenotype||Experiment Type||Experiment Type Category||Mutant Information||Strain Background||Chemical||Details||Reference|
|Evidence ID||Analyze ID||Regulator||Regulator Systematic Name||Target||Target Systematic Name||Experiment||Conditions||Strain||Source||Reference|