Chromatin Folding
Chromatin Folding - Related Videos
02:21
Chromatin Packaging
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2020
Each human somatic cell contains 6 billion base-pairs of DNA. Each base-pair is 0.34 nm long, which means that each diploid cell contains a staggering 2 meters of DNA. How is such a long DNA strand packed inside a nucleus measuring only 10 - 20 microns in diameter? The chromatin In combination with specialized DNA binding protein called Histones, the DNA double helix forms a compact DNA: protein complex called chromatin. The chromatin itself is further compacted into higher-order structures.
08:39
Chromatin Immunoprecipitation
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2023
Histones are proteins that help organize DNA in eukaryotic nuclei by serving as “scaffolds” around which DNA can be wrapped, forming a complex called “chromatin”. These proteins can be modified through the addition of chemical groups, and these changes affect gene expression. Researchers use a technique called chromatin immunoprecipitation (ChIP) to better understand which DNA regions associate with specific histone modifications or other gene regulatory proteins. Antibodies are used to isolate...
03:00
Molecular Chaperones and Protein Folding
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2020
The native conformation of a protein is formed by interactions between the side chains of its constituent amino acids. When the amino acids cannot form these interactions, the protein cannot fold by itself and needs chaperones. Notably, chaperones do not relay any additional information required for the folding of polypeptides; the native conformation of a protein is determined solely by its amino acid sequence. Chaperones catalyze protein folding without being a part of the folded protein. The...
04:57
Chromatin Shearing: A Method to Generate Chromatin Fragments Using Enzymatic Digestion
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2023
This video describes the protocol for chromatin shearing using micrococcal nuclease enzymatic digestion. Chromatin shearing is an essential step in Chromatin immunoprecipitation or ChIp workflow, which helps investigate protein-DNA interaction in human chronic myeloid leukemia cells. In the feature protocol chromatin shearing is performed using sonication.
02:25
Spreading of Chromatin Modifications
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2020
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 is an enzyme that can...
FAQs
Histone modifications help tune the accessibility and interaction potential of folded chromatin. Because DNA is wrapped around histones in nucleosomes, chemical changes to these associated proteins can alter how nucleosomes interact and how regulatory elements are positioned relative to genes. This provides a mechanism for linking local chromatin state with changes in transcription, replication, and DNA repair.
Cohesin and CTCF help organize contacts beyond individual nucleosomes. Their interactions contribute to the formation of chromatin loops and larger three-dimensional domains, arranging distant genomic regions into a spatial framework. That framework matters because regulatory elements influence genes most directly when folding places them in contact, making these architectural proteins important links between genome structure and gene regulation.
Chromatin folding is not a fixed packaging arrangement: its interactions can change as genome functions are regulated. Altering nucleosome interactions, histone modifications, or architectural-protein organization can change which regulatory elements contact genes. This flexibility allows the same DNA sequence to participate in different regulatory states and helps connect three-dimensional architecture with cell-specific patterns of activity.
Chromosome conformation capture provides an experimental way to examine genome architecture in living cells. By revealing which genomic regions are brought into proximity, the method can identify chromatin loops and larger three-dimensional domains, then relate those contacts to regulatory-element and gene relationships. Its value lies in measuring organization rather than inferring it solely from the DNA sequence.
Studies of chromatin folding can examine how genome architecture relates to cell differentiation, genome stability, and disease-associated changes. In differentiation, altered contacts between regulatory elements and genes may accompany shifts in genome function. In disease research, comparing folding patterns can help identify structural changes associated with abnormal regulation. This makes chromatin architecture relevant from developmental biology to disease-focused investigation.
Changes in chromatin folding can be interpreted through their effects on regulatory contacts and genome processes. A loop or domain arrangement may help explain why a regulatory element can influence a gene, whereas altered organization may be considered in relation to transcription, replication, or DNA repair. This framework lets biologists connect three-dimensional genome measurements with functional outcomes rather than treating structure as packaging alone.