Related Experiment Video
Updated: Sep 4, 2025
10:40
Assembly of Nucleosomal Arrays from Recombinant Core Histones and Nucleosome Positioning DNA
Published on: September 10, 2013
22.7K
Structures and consequences of pioneer factor binding to nucleosomes
Edgar Luzete-Monteiro1, Kenneth S Zaret2
1Institute for Regenerative Medicine, Department of Cell and Developmental Biology, Perelman School of Medicine, University of Pennsylvania, 9-131 SCTR, 3400 Civic Center Blvd., Philadelphia, PA 19104-5157, USA; Department of Biology, School of Arts and Sciences, University of Pennsylvania, 433 S University Ave, Philadelphia, PA 19104-4544, USA.
Current Opinion in Structural Biology
|July 21, 2022
Summary
Pioneer transcription factors bind nucleosomes to access silent chromatin, initiating gene expression changes crucial for development and disease. Biophysical studies reveal their strategies for nucleosome binding and DNA accessibility.
Area of Science:
- Molecular Biology
- Epigenetics
- Chromatin Biology
Background:
- Pioneer transcription factors target silent chromatin, which is compacted by linker histone.
- These factors bind nucleosomal DNA, promoting local exposure for other regulatory proteins.
Purpose of the Study:
- To review biophysical studies on pioneer transcription factor nucleosome binding.
- To elucidate the structural features and strategies enabling pioneer factor binding and subsequent DNA accessibility.
Main Methods:
- Review of recent biophysical studies.
- Analysis of structural features and binding strategies of pioneer factors.
Main Results:
- Pioneer factors bind partially exposed motifs on nucleosomes.
- Nucleosome binding by pioneer factors can lead to DNA accessibility.
- This process is critical for establishing gene expression programs.
Conclusions:
- Pioneer factors play a key role in regulating gene expression during cell fate determination.
- Understanding their nucleosome binding mechanisms is vital for insights into development, regeneration, and cancer.
Related Concept Videos
02:54Nucleosome Remodeling
9.4K
Nucleosomes are the basic units of chromatin compaction. Each nucleosome consists of the DNA bound tightly around a histone core, which makes the DNA inaccessible to DNA binding proteins such as DNA polymerase and RNA polymerase. Hence, the fundamental problem is to ensure access to DNA when appropriate, despite the compact and protective chromatin structure.
Nucleosome remodeling complex
Eukaryotic cells have specialized enzymes called ATP-dependent nucleosome remodeling enzymes. These enzymes...
Nucleosome remodeling complex
Eukaryotic cells have specialized enzymes called ATP-dependent nucleosome remodeling enzymes. These enzymes...
9.4K
01:12The Nucleosome Core Particle
1.2K
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...
1.2K
02:33The Nucleosome
16.6K
DNA in a human cell is almost 2m long and it is packed inside a tiny nucleus that is only a few microns in diameter. The level of compaction of DNA inside the nucleus is astonishing. It is organized into several sequentially higher levels of compaction to fit into such a tiny space. The most compact form of DNA is a chromosome that can be seen under a microscope in a dividing cell.
DNA is wound twice around a protein complex called histone core, that consist of 8 histone proteins. This complex...
DNA is wound twice around a protein complex called histone core, that consist of 8 histone proteins. This complex...
16.6K
02:16Transcription Factors
76.5K
Tissue-specific transcription factors contribute to diverse cellular functions in mammals. For example, the gene for beta globin, a major component of hemoglobin, is present in all cells of the body. However, it is only expressed in red blood cells because the transcription factors that can bind to the promoter sequences of the beta globin gene are only expressed in these cells. Tissue-specific transcription factors also ensure that mutations in these factors may impair only the function of...
76.5K
02:25Spreading of Chromatin Modifications
8.5K
The histone proteins in the nucleosomes are post-translationally modified (PTM) to increase or decrease access to DNA. The commonly observed PTMs are methylation, acetylation, phosphorylation, and ubiquitination of lysine amino acids in the histone H3 tail region. These histone modifications have specific meaning for the cell. Hence, they are called "histone code". The protein complex involved in histone modification is termed as "reader-writer" complex.
Writers
The writer...
Writers
The writer...
8.5K
02:35Transcription Elongation Factors
11.1K
Transcription elongation is a dynamic process that alters depending upon the sequence heterogeneity of the DNA being transcribed. Hence, it is not surprising that the elongation complex's composition also varies along the way while transcribing a gene.
The transcription elongation is regulated via pausing of RNA polymerase on several occasions during transcription. In bacteria, these halts are necessary because the transcription of DNA into mRNA is coupled to the translation of that mRNA...
The transcription elongation is regulated via pausing of RNA polymerase on several occasions during transcription. In bacteria, these halts are necessary because the transcription of DNA into mRNA is coupled to the translation of that mRNA...
11.1K