Related Experiment Video
Updated: Jun 16, 2026
08:12
Global Level Quantification of Histone Post-Translational Modifications in a 3D Cell Culture Model of Hepatic Tissue
Published on: May 5, 2022
New functions for an old variant: no substitute for histone H3.3
Simon J Elsaesser1, Aaron D Goldberg, C David Allis
1The Rockefeller University, New York, NY 10065, USA. selsaesser@rockefeller.edu <selsaesser@rockefeller.edu>
Current Opinion in Genetics & Development
|February 16, 2010
Summary
Histone variant H3.3, though similar to canonical H3, plays crucial roles beyond active transcription, including essential germline functions. Genetic studies reveal its surprising versatility in cellular and developmental processes.
Area of Science:
- Molecular Biology
- Genetics
- Epigenetics
Background:
- Histone proteins package DNA, with variants serving specialized roles.
- Histone H3.3 is traditionally linked to active transcription and histone replacement.
- Conserved function of H3.3 in yeast and metazoans has been observed.
Purpose of the Study:
- To investigate the conserved and novel functions of histone H3.3.
- To challenge the established role of H3.3 solely as a mark of active chromatin.
- To explore the essential functions of H3.3 in germline development.
Main Methods:
- Genetic studies in model organisms (e.g., flies).
- Comparative sequence analysis of histone variants.
- Chromatin analysis and functional assays.
Main Results:
- Recent genetic studies in flies question H3.3's exclusive role in active transcription.
- H3.3 demonstrates essential functions within the germline.
- Minimal amino acid differences between H3.3 and canonical H3 belie diverse functions.
Conclusions:
- Histone H3.3 has broader and more varied roles than previously understood.
- H3.3 is critical for germline development and other cellular processes.
- The specialized functions of H3.3 are achieved despite high sequence similarity to canonical H3.
Related Concept Videos
02:30Histone Variants at the Centromere
Histone variants are the histone proteins with structural and sequence variations. These variants may be regarded as “mutant” forms that replace their canonical histone counterparts in the nucleosomes. Specific post-translational modifications on the histone variants enable further chromatin complexity and regulate tissue-specific gene expression. The most common histone variants are from histone H2A, H2B, and linker histone H1 families. However, several variants of histone H3 variants are also...
02:32Histone Modification
The histone proteins have a flexible N-terminal tail extending out from the nucleosome. These histone tails are often subjected to post-translational modifications such as acetylation, methylation, phosphorylation, and ubiquitination. Particular combinations of these modifications form “histone codes” that influence the chromatin folding and tissue-specific gene expression.
Acetylation
The enzyme histone acetyltransferase adds acetyl group to the histones. Another enzyme, histone deacetylase,...
Acetylation
The enzyme histone acetyltransferase adds acetyl group to the histones. Another enzyme, histone deacetylase,...
02:32Histone Modification
The histone proteins have a flexible N-terminal tail extending out from the nucleosome. These histone tails are often subjected to post-translational modifications such as acetylation, methylation, phosphorylation, and ubiquitination. Particular combinations of these modifications form “histone codes” that influence the chromatin folding and tissue-specific gene expression.
Acetylation
The enzyme histone acetyltransferase adds acetyl group to the histones. Another enzyme, histone deacetylase,...
Acetylation
The enzyme histone acetyltransferase adds acetyl group to the histones. Another enzyme, histone deacetylase,...
01:12The Nucleosome Core Particle
Nucleosomes are the DNA-histone complex, where the DNA strand is wound around the histone core. The histone core is an octamer containing two copies of H2A, H2B, H3, and H4 histone proteins.
Nucleosomes, paradoxically, perform two opposite functions simultaneously. On the one hand, their primary aim is to protect the delicate DNA strands from physical damage and help achieve a higher compaction ratio. On the other hand, they must allow polymerase enzymes to access histone-bound DNA during...
Nucleosomes, paradoxically, perform two opposite functions simultaneously. On the one hand, their primary aim is to protect the delicate DNA strands from physical damage and help achieve a higher compaction ratio. On the other hand, they must allow polymerase enzymes to access histone-bound DNA during...
02:10The Nucleosome Core Particle
Nucleosomes are the DNA-histone complex, where the DNA strand is wound around the histone core. The histone core is an octamer containing two copies of H2A, H2B, H3, and H4 histone proteins.
The paradox
Nucleosomes, paradoxically, perform two opposite functions simultaneously. On the one hand, their main responsibility is to protect the delicate DNA strands from physical damage and help achieve a higher compaction ratio. While on the other hand, they must allow polymerase enzymes to access DNA...
The paradox
Nucleosomes, paradoxically, perform two opposite functions simultaneously. On the one hand, their main responsibility is to protect the delicate DNA strands from physical damage and help achieve a higher compaction ratio. While on the other hand, they must allow polymerase enzymes to access DNA...
02:32Position-effect Variegation
In 1928, a German botanist Emil Heitz observed the moss nuclei with a DNA binding dye. He observed that while some chromatin regions decondense and spread out in the interphase nucleus, others do not. He termed them euchromatin and heterochromatin, respectively. He proposed that the heterochromatin regions reflect a functionally inactive state of the genome. It was later confirmed that heterochromatin is transcriptionally repressed, and euchromatin is transcriptionally active chromatin.