scholarly journals The p55 subunit of Drosophila chromatin assembly factor 1 is homologous to a histone deacetylase-associated protein.

1996 ◽  
Vol 16 (11) ◽  
pp. 6149-6159 ◽  
Author(s):  
J K Tyler ◽  
M Bulger ◽  
R T Kamakaka ◽  
R Kobayashi ◽  
J T Kadonaga
Keyword(s):  
Drosophila Melanogaster ◽  
Dna Replication ◽  
Histone Modification ◽  
Molecular Mass ◽  
Histone Deacetylase ◽  
Nuclear Extract ◽  
Chromatin Assembly ◽  
Chromatin Assembly Factor ◽  
Assembly Factor

To gain a better understanding of DNA replication-coupled chromatin assembly, we have isolated the cDNA encoding the smallest (apparent molecular mass, 55 kDa; termed p55) subunit of Drosophila melanogaster chromatin assembly factor 1 (dCAF-1), a multisubunit protein that is required for the assembly of nucleosomes onto newly replicated DNA in vitro. The p55 polypeptide comprises seven WD repeat motifs and is homologous to the mammalian RbAp48 protein, which is associated with the HD1 histone deacetylase. dCAF-1 was immunopurified by using affinity-purified antibodies against p55; the resulting dCAF-1 preparation possessed the four putative subunits of dCAF-1 (p180, p105, p75, and p55) and was active for DNA replication-coupled chromatin assembly. Moreover, dCAF-1 activity was specifically depleted with antibodies against p55. Thus, p55 is an integral component of dCAF-1. p55 is localized to the nucleus and is present throughout Drosophila development. Consistent with the homology between p55 and the HD1-associated RbAp48 protein, histone deacetylase activity was observed to coimmunoprecipitate specifically with p55 from a Drosophila nuclear extract. Furthermore, a fraction of the p55 protein becomes associated with the newly assembled chromatin following DNA replication. These findings collectively suggest that p55 may function as a link between DNA replication-coupled chromatin assembly and histone modification.

scholarly journals Postreplicative chromatin assembly by Drosophila and human chromatin assembly factor 1.

1996 ◽  
Vol 16 (3) ◽  
pp. 810-817 ◽  
Author(s):  
R T Kamakaka ◽  
M Bulger ◽  
P D Kaufman ◽  
B Stillman ◽  
J T Kadonaga
Keyword(s):  
Dna Replication ◽  
Direct Interaction ◽  
Simian Virus 40 ◽  
Nuclear Extract ◽  
Simian Virus ◽  
T Antigen ◽  
Chromatin Assembly ◽  
Chromatin Assembly Factor ◽  
Assembly Factor

To study the relationship between DNA replication and chromatin assembly, we have purified a factor termed Drosophila chromatin assembly factor 1 (dCAF-1) to approximately 50% homogeneity from a nuclear extract derived from embryos. dCAF-1 appears to consist of four polypeptides with molecular masses of 180, 105, 75, and 55 kDa. dCAF-1 preferentially mediates chromatin assembly of newly replicated DNA relative to unreplicated DNA during T-antigen-dependent simian virus 40 DNA replication in vitro, as seen with human CAF-1. Analysis of the mechanism of DNA replication-coupled chromatin assembly revealed that both dCAF-1 and human CAF-1 mediate chromatin assembly preferentially with previously yet newly replicated DNA relative to unreplicated DNA. Moreover, the preferential assembly of the postreplicative DNA was observed at 30 min after inhibition of DNA replication by aphidicolin, but this effect slowly diminished until it was no longer apparent at 120 min after inhibition of replication. These findings suggest that the coupling between DNA replication and chromatin assembly may not necessarily involve a direct interaction between the replication and assembly factors at a replication fork.

scholarly journals Essential Role of Chromatin Assembly Factor-1–mediated Rapid Nucleosome Assembly for DNA Replication and Cell Division in Vertebrate Cells

2007 ◽  
Vol 18 (1) ◽  
pp. 129-141 ◽  
Author(s):  
Yasunari Takami ◽  
Tatsuya Ono ◽  
Tatsuo Fukagawa ◽  
Kei-ichi Shibahara ◽  
Tatsuo Nakayama
Keyword(s):  
Dna Replication ◽  
Essential Role ◽  
Chromatin Assembly ◽  
Nuclear Antigen ◽  
Nucleosome Assembly ◽  
Chromatin Assembly Factor ◽  
Assembly Factor

Chromatin assembly factor-1 (CAF-1), a complex consisting of p150, p60, and p48 subunits, is highly conserved from yeast to humans and facilitates nucleosome assembly of newly replicated DNA in vitro. To investigate roles of CAF-1 in vertebrates, we generated two conditional DT40 mutants, respectively, devoid of CAF-1p150 and p60. Depletion of each of these CAF-1 subunits led to delayed S-phase progression concomitant with slow DNA synthesis, followed by accumulation in late S/G2 phase and aberrant mitosis associated with extra centrosomes, and then the final consequence was cell death. We demonstrated that CAF-1 is necessary for rapid nucleosome formation during DNA replication in vivo as well as in vitro. Loss of CAF-1 was not associated with the apparent induction of phosphorylations of S-checkpoint kinases Chk1 and Chk2. To elucidate the precise role of domain(s) in CAF-1p150, functional dissection analyses including rescue assays were preformed. Results showed that the binding abilities of CAF-1p150 with CAF-1p60 and DNA polymerase sliding clamp proliferating cell nuclear antigen (PCNA) but not with heterochromatin protein HP1-γ are required for cell viability. These observations highlighted the essential role of CAF-1–dependent nucleosome assembly in DNA replication and cell proliferation through its interaction with PCNA.

scholarly journals Two Fundamentally Distinct PCNA Interaction Peptides Contribute to Chromatin Assembly Factor 1 Function

2009 ◽  
Vol 29 (24) ◽  
pp. 6353-6365 ◽  
Author(s):  
Tom Rolef Ben-Shahar ◽  
Araceli G. Castillo ◽  
Michael J. Osborne ◽  
Katherine L. B. Borden ◽  
Jack Kornblatt ◽  
...  
Keyword(s):  
Dna Replication ◽  
Large Subunit ◽  
Chromatin Assembly ◽  
Nuclear Antigen ◽  
Replication Forks ◽  
Nucleosome Assembly ◽  
Chromatin Assembly Factor ◽  
Assembly Factor

ABSTRACT Chromatin assembly factor 1 (CAF-1) deposits histones H3 and H4 rapidly behind replication forks through an interaction with the proliferating cell nuclear antigen (PCNA), a DNA polymerase processivity factor that also binds to a number of replication enzymes and other proteins that act on nascent DNA. The mechanisms that enable CAF-1 and other PCNA-binding proteins to function harmoniously at the replication fork are poorly understood. Here we report that the large subunit of human CAF-1 (p150) contains two distinct PCNA interaction peptides (PIPs). The N-terminal PIP binds strongly to PCNA in vitro but, surprisingly, is dispensable for nucleosome assembly and only makes a modest contribution to targeting p150 to DNA replication foci in vivo. In contrast, the internal PIP (PIP2) lacks one of the highly conserved residues of canonical PIPs and binds weakly to PCNA. Surprisingly, PIP2 is essential for nucleosome assembly during DNA replication in vitro and plays a major role in targeting p150 to sites of DNA replication. Unlike canonical PIPs, such as that of p21, the two p150 PIPs are capable of preferentially inhibiting nucleosome assembly, rather than DNA synthesis, suggesting that intrinsic features of these peptides are part of the mechanism that enables CAF-1 to function behind replication forks without interfering with other PCNA-mediated processes.

scholarly journals Chromatin assembly factor-1 (CAF-1) chaperone regulates Cse4 deposition into chromatin in budding yeast

2018 ◽  
Vol 46 (9) ◽  
pp. 4440-4455 ◽  
Author(s):  
Geetha S Hewawasam ◽  
Karthik Dhatchinamoorthy ◽  
Mark Mattingly ◽  
Chris Seidel ◽  
Jennifer L Gerton
Keyword(s):  
Gene Expression ◽  
Chromosome Segregation ◽  
Budding Yeast ◽  
Chromatin Assembly ◽  
Growth Defects ◽  
Chromatin Assembly Factor ◽  
Genome Wide ◽  
Assembly Factor ◽  
Underlying Mechanisms

Abstract Correct localization of the centromeric histone variant CenH3/CENP-A/Cse4 is an important part of faithful chromosome segregation. Mislocalization of CenH3 could affect chromosome segregation, DNA replication and transcription. CENP-A is often overexpressed and mislocalized in cancer genomes, but the underlying mechanisms are not understood. One major regulator of Cse4 deposition is Psh1, an E3 ubiquitin ligase that controls levels of Cse4 to prevent deposition into non-centromeric regions. We present evidence that Chromatin assembly factor-1 (CAF-1), an evolutionarily conserved histone H3/H4 chaperone with subunits shown previously to interact with CenH3 in flies and human cells, regulates Cse4 deposition in budding yeast. yCAF-1 interacts with Cse4 and can assemble Cse4 nucleosomes in vitro. Loss of yCAF-1 dramatically reduces the amount of Cse4 deposited into chromatin genome-wide when Cse4 is overexpressed. The incorporation of Cse4 genome-wide may have multifactorial effects on growth and gene expression. Loss of yCAF-1 can rescue growth defects and some changes in gene expression associated with Cse4 deposition that occur in the absence of Psh1-mediated proteolysis. Incorporation of Cse4 into promoter nucleosomes at transcriptionally active genes depends on yCAF-1. Overall our findings suggest CAF-1 can act as a CenH3 chaperone, regulating levels and incorporation of CenH3 in chromatin.

scholarly journals Physical and Functional Interaction between the Bloom's Syndrome Gene Product and the Largest Subunit of Chromatin Assembly Factor 1

2004 ◽  
Vol 24 (11) ◽  
pp. 4710-4719 ◽  
Author(s):  
Renjie Jiao ◽  
Csanád Z. Bachrati ◽  
Graziella Pedrazzi ◽  
Patrick Kuster ◽  
Maja Petkovic ◽  
...  
Keyword(s):  
Dna Repair ◽  
Cancer Susceptibility ◽  
Chromatin Assembly ◽  
Bloom's Syndrome ◽  
Functional Interaction ◽  
Chromatin Assembly Factor ◽  
Bloom’S Syndrome ◽  
Hydroxyurea Treatment ◽  
Assembly Factor

ABSTRACT Bloom's syndrome (BS) is a genomic instability disorder characterized by cancer susceptibility. The protein defective in BS, BLM, belongs to the RecQ family of DNA helicases. In this study, we found that BLM interacts with hp150, the largest subunit of chromatin assembly factor 1 (CAF-1), in vitro and in vivo. Colocalization of a proportion of the cellular complement of these two proteins is found at specific nuclear foci coinciding with sites of DNA synthesis in the S phase. This colocalization increases in the presence of agents that damage DNA or inhibit DNA replication. In support of a functional interaction between BLM and CAF-1, we show that BLM inhibits CAF-1-mediated chromatin assembly during DNA repair in vitro. Although CAF-1 activity is not altered in BLM-deficient cells, the absence of BLM does impair the ability of CAF-1 to be mobilized within the nucleus in response to hydroxyurea treatment. Our results provide the first link between BLM and chromatin assembly coupled to DNA repair and suggest that BLM and CAF-1 function in a coordinated way to promote survival in response to DNA damage and/or replication blockade.

scholarly journals CAF-1 and the inheritance of chromatin states: at the crossroads of DNA replication and repair

2000 ◽  
Vol 113 (15) ◽  
pp. 2647-2658 ◽  
Author(s):  
P. Ridgway ◽  
G. Almouzni
Keyword(s):  
Dna Replication ◽  
Chromatin Assembly ◽  
Genome Integrity ◽  
Chromatin States ◽  
Structural Framework ◽  
Cell Extracts ◽  
Dna Replication And Repair ◽  
Assembly Factor ◽  
Ordered Assembly

Chromatin is no longer considered to be a static structural framework for packaging DNA within the nucleus but is instead believed to be an interactive component of DNA metabolism. The ordered assembly of chromatin produces a nucleoprotein template capable of epigenetically regulating the expression and maintenance of the genome. Factors have been isolated from cell extracts that stimulate early steps in chromatin assembly in vitro. The function of one such factor, chromatin-assembly factor 1 (CAF-1), might extend beyond simply facilitating the progression through an individual assembly reaction to its active participation in a marking system. This marking system could be exploited at the crossroads of DNA replication and repair to monitor genome integrity and to define particular epigenetic states.

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