Heterochromatin dynamics in mouse cells: interaction between chromatin assembly factor 1 and HP1 proteins.
Mechanisms contributing to the maintenance of heterochromatin in proliferating cells are poorly understood. We demonstrate that chromatin assembly factor 1 (CAF-1) binds to mouse HP1 proteins via an N-terminal domain of its p150 subunit, a domain dispensable for nucleosome assembly during DNA replication. Mutations in p150 prevent association with HP1 in heterochromatin in cells that are not in S phase and the formation of CAF-1-HP1 complexes in nascent chromatin during DNA replication in vitro. We suggest that CAF-1 p150 has a heterochromatin-specific function distinct from its nucleosome assembly function during S phase. Just before mitosis, CAF-1 p150 and some HP1 progressively dissociate from heterochromatin concomitant with histone H3 phosphorylation. The HP1 proteins reassociate with chromatin at the end of mitosis, as histone H3 is dephosphorylated.
Murzina
N
N
Cambridge Centre for Molecular Recognition, Department of Biochemistry, University of Cambridge, United Kingdom.
Verreault
A
A
Laue
E
E
Stillman
B
B
D016475:3T3 Cells; D000595:Amino Acid Sequence; D000818:Animals; D056504:Chromatin Assembly Factor-1; D000090266:Chromobox Protein Homolog 5; D002868:Chromosomal Proteins, Non-Histone / Q000378:metabolism*; D004261:DNA Replication / Q000235:genetics; D004268:DNA-Binding Proteins / Q000378:metabolism*; D005455:Fluorescent Antibody Technique; D049452:Green Fluorescent Proteins; D006570:Heterochromatin / Q000378:metabolism*; D006657:Histones / Q000378:metabolism; D008164:Luminescent Proteins; D051379:Mice; D008938:Mitosis; D008969:Molecular Sequence Data; D009154:Mutation; D009687:Nuclear Proteins; D010766:Phosphorylation; D011485:Protein Binding; D012097:Repressor Proteins / Q000378:metabolism; D016196:S Phase; D014157:Transcription Factors; D000076183:Tripartite Motif-Containing Protein 28; D015003:Yeasts / Q000235:genetics
C533592:Chaf1a protein, mouse; D056504:Chromatin Assembly Factor-1; D002868:Chromosomal Proteins, Non-Histone; D004268:DNA-Binding Proteins; D006570:Heterochromatin; D006657:Histones; D008164:Luminescent Proteins; D009687:Nuclear Proteins; D012097:Repressor Proteins; D014157:Transcription Factors; D000090266:Chromobox Protein Homolog 5; D049452:Green Fluorescent Proteins; C103190:Trim28 protein, mouse; D000076183:Tripartite Motif-Containing Protein 28