Histone proteins and the nucleosomes they form with DNA are the fundamental building blocks of eukaryotic chromatin. A diverse array of post-translational modifications that often occur on tail domains of these proteins has been well documented. Although the function of these highly conserved modifications has remained elusive, converging biochemical and genetic evidence suggests functions in several chromatin-based processes. We propose that distinct histone modifications, on one or more tails, act sequentially or in combination to form a 'histone code' that is, read by other proteins to bring about distinct downstream events.

The language of covalent histone modifications.

https://www.cell.com/cell/pdf/S0092-8674(07)00594-6.pdf

PCNA, the Maestro of the Replication Fork

Histone acetylation regulates many cellular processes, and specific acetylation marks, either singly or in combination, produce distinct outcomes. For example, the acetylation pattern on newly synthesized histones is important for their assembly into nucleosomes by histone chaperones. Additionally, the degree of chromatin compaction and folding may be regulated by acetylation of histone H4 at lysine 16. Histone acetylation also regulates the formation of heterochromatin; deacetylation of H4 lysine 16 is important for spreading of heterochromatin components, whereas acetylation of this site serves as a barrier to this spreading. Finally, histone acetylation is critical for gene transcription, but recent results suggest that deacetylation of certain sites also plays an important role. There are many histone acetyltransferases (HATs) and deacetylases, with differing preferences for the various histone proteins and for specific sites on individual histones. Determining how these enzymes create distinc...

Functions of site-specific histone acetylation and deacetylation.

https://www.cell.com/cell/pdf/S0092-8674(03)01064-X.pdf

Histone H3.1 and H3.3 Complexes Mediate Nucleosome Assembly Pathways Dependent or Independent of DNA Synthesis

http://www.gs.washington.edu/academics/courses/braun/55105/readings/ahmad.pdf

The histone variant H3.3 marks active chromatin by replication-independent nucleosome assembly.

Chromatin assembly is a fundamental biological process that is essential for the replication and maintenance of the eukaryotic genome1,2,3,4 In dividing cells, newly synthesized DNA is rapidly assembled into chromatin by the deposition of a tetramer of the histone proteins H3 and H4, followed by the deposition of two dimers of histones H2A and H2B to complete the nucleosome—the fundamental repeating unit of chromatin5 Here we describe the identification, purification, cloning, and characterization of replication-coupling assembly factor (RCAF), a novel protein complex that facilitates the assembly of nucleosomes onto newly replicated DNA in vitro RCAF comprises the Drosophila homologue of anti-silencing function 1 protein ASF16 and histones H3 and H4 The specific acetylation pattern of H3 and H4 in RCAF is identical to that of newly synthesized histones Genetic analyses in Saccharomyces cerevisiae demonstrate that ASF1 is essential for normal cell cycle progression, and suggest that RCAF mediates chromatin assembly after DNA replication and the repair of double-strand DNA damage in vivo

The RCAF complex mediates chromatin assembly during DNA replication and repair

Chromatin assembly is a fundamental biological process that is essential for the replication and maintenance of the eukaryotic genome1,2,3,4. In dividing cells, newly synthesized DNA is rapidly assembled into chromatin by the deposition of a tetramer of the histone proteins H3 and H4, followed by the deposition of two dimers of histones H2A and H2B to complete the nucleosome—the fundamental repeating unit of chromatin5. Here we describe the identification, purification, cloning, and characterization of replication-coupling assembly factor (RCAF), a novel protein complex that facilitates the assembly of nucleosomes onto newly replicated DNA in vitro. RCAF comprises the Drosophila homologue of anti-silencing function 1 protein ASF16 and histones H3 and H4. The specific acetylation pattern of H3 and H4 in RCAF is identical to that of newly synthesized histones. Genetic analyses in Saccharomyces cerevisiae demonstrate that ASF1 is essential for normal cell cycle progression, and suggest that RCAF mediates chromatin assembly after DNA replication and the repair of double-strand DNA damage in vivo.

Shaw Ree Chen

Papers

The RCAF complex mediates chromatin assembly during DNA replication and repair

The RCAF complex mediates chromatin assembly during DNA replication and repair