# Enhancer-Promoter Interaction: Mechanisms and Methods

## Introduction to Enhancer-Promoter Interactions

### What are Enhancers and Promoters?

Gene transcription in eukaryotes is controlled by two principal classes of *cis*-regulatory DNA elements: promoters and enhancers. A **promoter** is the DNA sequence located immediately upstream of the transcription start site (TSS), typically spanning roughly 100–1000 base pairs. It contains the core promoter elements—such as the TATA box, initiator (Inr), and downstream promoter element (DPE)—that serve as the binding platform for the general transcription machinery, including RNA polymerase II (Pol II) and the basal [transcription factors](/knowledge/molecular-biology/transcription-factor) TFIID, TFIIB, TFIIE, TFIIF, and TFIIH. The promoter determines where transcription initiates but generally drives only low, basal levels of expression on its own.

An **enhancer** is a distal regulatory DNA element, typically 100–1000 base pairs in length, that can activate transcription of a target gene from a distance. Enhancers function independent of their orientation relative to the promoter and can act over genomic distances ranging from a few kilobases to over a megabase. They are densely bound by sequence-specific transcription factors (TFs) and coactivators, and they are marked by characteristic chromatin features, including histone H3 lysine 27 acetylation (H3K27ac) and H3 lysine 4 monomethylation (H3K4me1). For a more detailed comparison of these elements, see [DNA Enhancer vs Promoter](/knowledge/molecular-biology/dna-enhancer-vs-promoter).

### Why Do They Interact?

The fundamental question in gene regulation is how a distal enhancer, located tens or hundreds of kilobases away, influences the activity of its target promoter. The prevailing answer is that the intervening DNA is looped out so that the enhancer and promoter are brought into close three-dimensional proximity within the nucleus. This physical contact allows the enhancer-bound activator proteins to directly communicate with the promoter-bound basal machinery, recruiting coactivators, [chromatin remodelers](/knowledge/molecular-biology/chromatin-remodelers), and ultimately Pol II to initiate transcription.

This interaction is not a static, always-on connection. Rather, enhancer-promoter contacts are dynamic, cell-type-specific, and developmentally regulated. A given enhancer may contact its target promoter in one cell type but not another, and the strength and frequency of the contact often correlate with the level of transcriptional output. Understanding the mechanisms that establish, maintain, and dissolve these interactions is central to understanding how precise spatiotemporal patterns of [gene expression](/blog/guides/gene-expression) are achieved.

## The Role of Chromatin Architecture

### Chromatin Looping

The linear DNA in a eukaryotic nucleus is packaged into chromatin, but this packaging is not a simple linear string. Instead, the genome is folded into a hierarchy of three-dimensional structures that bring distant sequences into proximity. The key concept is **chromatin looping**: the physical extrusion of the intervening DNA between an enhancer and its target promoter to form a loop. This loop brings the two elements into direct contact, typically within a distance of a few nanometers, allowing protein-protein interactions to occur across the loop.

Chromatin loops are not random. They are formed and stabilized by a combination of sequence-specific DNA-binding proteins, architectural proteins, and the process of loop extrusion by cohesin. The formation of a loop requires that the enhancer and promoter be brought together by the motor activity of cohesin, which translocates along the DNA, extruding a loop until it encounters boundary elements, typically bound by CTCF (CCCTC-binding factor). The loop is then anchored at these boundaries, and the enhancer-promoter contact is stabilized within the loop.

### Topologically Associating Domains (TADs)

At a scale of hundreds of kilobases to a megabase, the genome is organized into **topologically associating domains (TADs)**. TADs are self-interacting genomic regions within which DNA sequences contact each other more frequently than they contact sequences outside the domain. They are demarcated by boundaries that are enriched for CTCF binding and housekeeping genes. TADs are thought to function as regulatory units: enhancers and promoters within the same TAD interact preferentially, while interactions across TAD boundaries are suppressed.

The functional significance of TADs is illustrated by the fact that enhancers typically act on promoters within the same TAD. Disruption of a TAD boundary—for example, by a genomic deletion or a mutation in a CTCF binding site—can cause an enhancer to inappropriately contact and activate a promoter in a neighboring TAD, leading to ectopic gene expression and disease. This phenomenon is well documented at the human *EPHA4* locus, where TAD boundary disruption causes limb malformations due to aberrant enhancer-promoter contacts. TADs thus both facilitate productive enhancer-promoter interactions by increasing the local concentration of regulatory elements and constrain them by insulating genes from enhancers outside the domain.

## Key Protein Players in the Interaction

### Transcription Factors and Coactivators

The specificity of enhancer-promoter interactions is largely determined by sequence-specific transcription factors (TFs). These proteins bind to clusters of motifs within enhancers and, to a lesser extent, promoters. Each cell type expresses a distinct set of TFs, and the combination of TFs bound at an enhancer determines its activity and its target promoter selectivity.

TFs recruit **coactivators**—large multiprotein complexes that do not bind DNA directly but mediate the functional output of TF binding. Key coactivators include:

- **Mediator**: A 26-subunit complex that bridges enhancer-bound TFs and the Pol II preinitiation complex at the promoter. Mediator is essential for enhancer-dependent activation and is physically present at both enhancers and promoters during active transcription.
- **p300/CBP**: Histone acetyltransferases that deposit H3K27ac at enhancers, opening chromatin and providing binding sites for bromodomain-containing proteins such as BRD4.
- **SWI/SNF (BAF)**: An ATP-dependent [chromatin remodeling](/knowledge/molecular-biology/chromatin-remodeling) complex that mobilizes nucleosomes, increasing DNA accessibility at enhancers and promoters.

These coactivators do not simply diffuse to the promoter; they are delivered via the physical contact between the enhancer and promoter. The enhancer-bound TF-coactivator complex is thus positioned to directly modify the promoter-proximal chromatin and recruit Pol II.

### CTCF and Cohesin

Two architectural proteins are central to the formation and maintenance of enhancer-promoter loops: **CTCF** and **cohesin**.

**CTCF** is an 11-zinc-finger DNA-binding protein that binds to a conserved ~15-base-pair motif. It is the primary organizer of TAD boundaries and loop anchors. CTCF binding is directional: the motif has an orientation, and loops are preferentially formed between CTCF sites in a convergent orientation (one pointing toward the other). CTCF does not directly mediate enhancer-promoter contacts; rather, it establishes the boundaries within which such contacts occur.

**Cohesin** is a ring-shaped protein complex composed of SMC1, SMC3, RAD21, and STAG subunits. It has two roles: sister chromatid cohesion during mitosis and, in interphase, loop extrusion. Cohesin is loaded onto DNA at sites enriched for the loader NIPBL and translocates along the DNA, extruding a loop until it encounters a CTCF-bound boundary. The loop is then stabilized, and the enhancer and promoter within the loop are brought into proximity. Cohesin's ATPase activity is required for loop extrusion, and its removal—for example, by the cohesin release factor WAPL—destabilizes loops.

The interplay between CTCF and cohesin is critical. CTCF provides the boundary, and cohesin provides the motor and the structural scaffold. However, not all enhancer-promoter loops are anchored by CTCF. Many are formed by TF-mediated contacts that do not require CTCF, and the stability of these loops is often lower. The relative contribution of CTCF-anchored versus TF-anchored loops varies across loci and cell types.

## Mechanisms of Enhancer-Promoter Communication

### Looping Model

The **looping model** is the most widely supported mechanism for enhancer-promoter communication. It proposes that the enhancer and promoter are brought into direct physical contact by the looping out of the intervening DNA. This contact is mediated by protein-protein interactions between enhancer-bound activators and coactivators and the promoter-bound basal machinery.

The looping model is supported by a large body of evidence from chromosome conformation capture (3C) experiments, which detect physical proximity between genomic loci. In these experiments, an enhancer and its target promoter show significantly higher interaction frequency than would be expected from their linear distance. The looping model also explains how an enhancer can act over large genomic distances: the intervening DNA is simply extruded into a loop, and the distance in three-dimensional space, not linear sequence, is what matters.

The looping model predicts that the rate of transcription is proportional to the frequency and duration of enhancer-promoter contacts. Single-molecule imaging studies have confirmed that enhancer-promoter contacts are dynamic, with individual contacts lasting on the order of seconds to minutes, and that the frequency of contacts correlates with transcriptional bursting.

### Tracking Model

The **tracking model** proposes that, rather than forming a static loop, the enhancer-bound complex translocates along the DNA from the enhancer to the promoter, "tracking" through the intervening chromatin. This model was originally proposed to explain the action of enhancers in prokaryotes and was later applied to eukaryotes.

In the tracking model, the enhancer-bound activator complex recruits a tracking factor—possibly RNA polymerase II itself or a helicase—that moves along the DNA, remodeling chromatin and ultimately delivering the activation signal to the promoter. Evidence for tracking comes from observations that transcription can occur within the intervening region between an enhancer and promoter, producing noncoding RNAs called eRNAs. However, the tracking model is not mutually exclusive with looping; some studies suggest that tracking may occur within the context of a loop, with the tracking factor moving along the extruded DNA to reach the promoter.

The tracking model is less well supported than the looping model for most enhancer-promoter pairs, but it may be relevant for certain loci, particularly those where enhancers are located very close to promoters or where the intervening region contains regulatory elements that must be traversed.

### Other Models

Several other models have been proposed to explain enhancer-promoter communication:

- **The linking model**: Proposes that the enhancer and promoter are connected by a chain of protein-protein interactions along the intervening DNA, without requiring direct contact between the enhancer and promoter. This model is essentially a variant of the tracking model, with the "link" being a series of bound proteins rather than a moving complex.
- **The nuclear compartment model**: Proposes that enhancers and promoters are brought into proximity by their shared localization in specific nuclear subcompartments, such as transcription factories or nuclear speckles. In this model, the enhancer and promoter do not need to form a specific loop; they simply co-occupy a region of the nucleus where the concentration of transcription machinery is high.
- **The phase separation model**: A more recent proposal that enhancers and promoters are brought together by liquid-liquid phase separation of their associated proteins. The high local concentration of TFs, coactivators, and Pol II at active enhancers and promoters can drive the formation of phase-separated condensates, which concentrate the transcription machinery and facilitate enhancer-promoter communication.

These models are not mutually exclusive, and different loci may use different mechanisms. The looping model remains the dominant framework, but the phase separation model is gaining support as an explanation for how enhancer-promoter contacts are stabilized and how transcription is activated at high levels.

## Methods to Study Enhancer-Promoter Interactions

### Chromatin Conformation Capture (3C) and Derivatives

The development of **chromosome conformation capture (3C)** revolutionized the study of enhancer-promoter interactions. The basic principle of 3C is to crosslink physically proximal DNA sequences, digest the crosslinked chromatin with a restriction enzyme, ligate the resulting fragments under dilute conditions that favor intramolecular ligation, and then detect ligation products by PCR.

The 3C protocol involves the following steps:

1. Crosslink cells with 1–2% formaldehyde for 10 minutes at room temperature to covalently fix protein-DNA and protein-protein interactions.
2. Quench the crosslinking with glycine (0.125 M final concentration).
3. Lyse the cells and digest the chromatin with a restriction enzyme (e.g., HindIII, EcoRI, or a 4-base cutter like DpnII) overnight at 37°C.
4. Ligate the digested fragments with T4 DNA ligase under dilute conditions (typically 1–5 ng/µL DNA) for 4–6 hours at 16°C to promote intramolecular ligation.
5. Reverse the crosslinks by proteinase K digestion and heat, then purify the DNA.
6. Detect specific ligation products by quantitative PCR using primers flanking the restriction sites of interest.

3C measures the interaction frequency between two specific loci. It is a "one-to-one" method: you must know both the enhancer and the promoter you are testing. It is powerful for validating candidate interactions but is low-throughput.

**3C-on-chip (4C)** is a "one-to-all" method that measures the interactions of one locus (the "viewpoint") with all other loci in the genome. It involves a second round of digestion and ligation to create circular DNA molecules, followed by inverse PCR from the viewpoint and detection on a microarray or by high-throughput sequencing.

**Carbon-copy chromosome conformation capture (5C)** is an "all-to-all" method for a defined region. It uses a multiplexed ligation-mediated amplification to detect all pairwise interactions within a genomic region of interest, typically up to a few megabases. 5C is useful for mapping the interaction landscape of a TAD.

### Hi-C and Its Variants

**Hi-C** is a genome-wide version of 3C. The key difference is that, after ligation, the DNA is sheared, and the ligation junctions are enriched by biotin pulldown before sequencing. The Hi-C protocol includes the following modifications to 3C:

1. After ligation, the DNA is sheared by sonication to a size of 300–500 base pairs.
2. The sheared DNA is end-repaired, and biotinylated nucleotides are incorporated at the ligation junctions.
3. The biotinylated DNA is pulled down with streptavidin beads.
4. The enriched DNA is subjected to paired-end sequencing.

Hi-C produces a genome-wide contact map at a resolution determined by [sequencing depth](/knowledge/diagnostics/molecular/how-to-calculate-sequencing-depth-and-coverage-for-your-ngs-run). At low resolution (e.g., 1 Mb), Hi-C reveals TADs and compartments. At high resolution (e.g., 5–10 kb), it can identify individual enhancer-promoter loops, although this requires very [deep sequencing](/knowledge/molecular-biology/deep-sequencing) (billions of reads).

**Capture Hi-C (CHi-C)** and **promoter capture Hi-C (PCHi-C)** are variants that enrich Hi-C libraries for specific regions of interest using biotinylated RNA probes. PCHi-C targets all annotated promoters, allowing the detection of enhancer-promoter interactions at high resolution without the cost of ultra-deep whole-genome Hi-C.

**Micro-C** is a variant that uses micrococcal nuclease (MNase) instead of a restriction enzyme to fragment chromatin. MNase digests the DNA between nucleosomes, producing higher resolution maps that can detect interactions at nucleosome resolution. Micro-C is particularly useful for studying enhancer-promoter interactions at loci with high gene density.

### CRISPR-Based Approaches

While 3C-based methods detect interactions, they do not directly test their functional significance. **CRISPR-based approaches** allow the perturbation of specific enhancers, promoters, or the loops between them.

**CRISPR interference (CRISPRi)** uses a catalytically dead Cas9 (dCas9) fused to a [transcriptional repressor](/knowledge/molecular-biology/transcriptional-repressor) domain, such as KRAB. When targeted to an enhancer or promoter, dCas9-KRAB recruits histone methyltransferases (e.g., G9a) and deacetylases, depositing repressive marks (H3K9me3) and reducing chromatin accessibility. This can be used to test whether a putative enhancer is required for the expression of a target gene.

**CRISPR activation (CRISPRa)** uses dCas9 fused to a transcriptional activator, such as VP64 or the VPR domain. Targeting dCas9-VP64 to an enhancer can activate its target gene, testing whether the enhancer is sufficient to drive expression.

**CRISPR-Cas9 genome editing** can be used to delete enhancers, promoters, or CTCF binding sites, or to invert CTCF motifs, directly testing the role of these elements in enhancer-promoter interactions. For example, deleting a CTCF site at a TAD boundary can cause an enhancer to ectopically activate a promoter in a neighboring TAD, demonstrating the insulating function of the boundary.

**CRISPR-GO (CRISPR-genome organization)** is a more recent technique that uses dCas9 fused to protein domains that can tether a locus to a specific nuclear compartment, such as the nuclear periphery or a transcription factory. This allows the direct manipulation of nuclear positioning and the testing of its effect on enhancer-promoter interactions and gene expression.

## Functional Evidence from Gene Regulation

### Developmental Gene Regulation

Enhancer-promoter interactions are essential for the precise spatiotemporal control of gene expression during development. A classic example is the **β-globin locus** in erythroid cells. The locus contains five β-like globin genes (ε, Gγ, Aγ, δ, and β) arranged in the order of their developmental expression. A locus control region (LCR), located 20–60 kb upstream of the genes, contains multiple enhancers that are bound by erythroid-specific transcription factors such as GATA1 and TAL1.

In erythroid progenitors, the LCR forms a loop with the active β-globin promoter, activating transcription. In non-erythroid cells, the LCR does not contact the β-globin promoter, and the gene is silent. The loop is mediated by the erythroid-specific factor LDB1, which dimerizes and bridges the LCR and the promoter. Deletion of LDB1 or its binding sites in the LCR abolishes the loop and reduces β-globin expression by over 100-fold.

Another example is the **HoxD locus**, which controls limb development. During limb bud formation, enhancers located in a large genomic region flanking the HoxD cluster sequentially contact different HoxD genes, activating them in a collinear manner. The switch in enhancer-promoter contacts is regulated by changes in TAD organization and by the binding of specific TFs, such as HOX13 proteins, which remodel the chromatin architecture.

### Enhancer Mutations and Disease

Mutations that disrupt enhancer-promoter interactions are a major cause of human disease. These mutations can be classified into several types:

1. **Enhancer deletions or point mutations**: A mutation in an enhancer that abolishes TF binding can reduce or eliminate the expression of its target gene. For example, mutations in the *SHH* enhancer ZRS (zone of polarizing activity regulatory sequence) cause preaxial polydactyly. The ZRS is located ~1 Mb upstream of the *SHH* gene, and mutations that create ectopic TF binding sites cause the enhancer to be active in inappropriate limb regions, leading to abnormal digit formation.

2. **Promoter mutations**: Mutations in the promoter that disrupt the binding of the basal transcription machinery or of specific TFs can reduce transcription. For example, mutations in the *TERT* promoter create binding sites for ETS transcription factors, leading to aberrant activation of [telomerase in cancer cells](/knowledge/molecular-biology/telomerase-in-cancer-cells).

3. **Structural variants that disrupt TAD boundaries**: Deletions, duplications, or inversions that remove or reposition a TAD boundary can cause an enhancer to inappropriately contact a promoter in a neighboring TAD. This is the mechanism underlying several congenital limb malformations at the *EPHA4* locus, where deletions of a TAD boundary cause the *EPHA4* enhancers to activate the *PAX3* gene, leading to abnormal limb development.

4. **CTCF site mutations**: Mutations that disrupt CTCF binding at a TAD boundary or loop anchor can alter enhancer-promoter interactions. In some cancers, somatic mutations in CTCF binding sites are associated with aberrant gene activation.

The study of these disease-associated mutations has provided strong evidence that enhancer-promoter interactions are functionally important, not just correlative. When an interaction is disrupted, gene expression changes, and disease results.

## Common Pitfalls and Misconceptions

### Correlation vs. Causation

The most common error students make is assuming that a detected interaction between an enhancer and a promoter is functionally significant. 3C-based methods detect proximity, not function. An enhancer and promoter may be in close physical proximity simply because they are in the same TAD or because the locus is compacted, without the interaction driving transcription.

To establish causation, you need perturbation experiments. Deleting the enhancer, mutating its TF binding sites, or disrupting the loop (e.g., by removing CTCF sites) and observing a change in gene expression provides functional evidence. Without such perturbation, an interaction is merely correlative.

A related pitfall is assuming that the strength of the interaction (measured by 3C frequency) directly reflects the level of transcriptional activation. While there is often a correlation, the relationship is not linear. Some enhancers form stable, high-frequency contacts with their promoters but drive only modest activation, while others form transient, low-frequency contacts that drive high levels of transcription. The frequency of contact is only one parameter; the duration, the protein composition of the contact, and the local concentration of Pol II also matter.

### The Importance of Context

A second major pitfall is ignoring the chromatin and nuclear context. Enhancer-promoter interactions do not occur in a vacuum. They are influenced by:

- **The local chromatin state**: Heterochromatin is generally refractory to enhancer-promoter interactions, while active chromatin (marked by H3K27ac and H3K4me1) is permissive.
- **The presence of insulators**: CTCF-bound boundaries can block enhancer-promoter interactions, even if the enhancer and promoter are in close linear proximity.
- **The nuclear position**: Loci at the nuclear periphery are generally less accessible to the transcription machinery and show fewer enhancer-promoter interactions than loci in the nuclear interior.
- **The cell cycle**: Chromatin architecture is reorganized during mitosis, and enhancer-promoter interactions are largely lost when chromosomes condense. They are re-established in G1, and the timing of re-establishment can vary between loci.

Students often treat enhancer-promoter interactions as a binary property (interacting or not), but in reality they are dynamic and probabilistic. A given enhancer-promoter pair may interact in 20% of cells at any given time, and this fraction can change rapidly in response to signaling.

Another misconception is that enhancers always interact with the nearest promoter. This is false. Enhancers can skip over nearby genes to activate more distant promoters, and they can be blocked by insulators. The specificity of enhancer-promoter interactions is determined by the combination of TF binding, chromatin state, and architectural proteins, not simply by linear distance.

Finally, students sometimes confuse the directionality of interactions. Enhancer-promoter interactions are not directional in the sense of a one-way signal from enhancer to promoter. The interaction is bidirectional in the sense that the promoter can also influence the enhancer (e.g., by promoting eRNA transcription), and the interaction is dynamic, with the enhancer and promoter coming together and apart repeatedly.

## Summary and Key Takeaways

Enhancer-promoter interactions are the physical basis of distal gene regulation in eukaryotes. They are mediated by the three-dimensional folding of chromatin, which brings distal regulatory elements into proximity with their target promoters. This proximity allows enhancer-bound transcription factors and coactivators to directly influence the promoter-bound basal transcription machinery, activating transcription.

The key players are sequence-specific TFs, coactivators like Mediator and p300, and the architectural proteins CTCF and cohesin. TFs provide specificity, coactivators provide the functional output, and CTCF and cohesin provide the structural framework for loop formation.

Multiple mechanisms have been proposed for how enhancers communicate with promoters, with the looping model being the most supported. The tracking model and phase separation model offer alternative or complementary explanations.

The study of enhancer-promoter interactions relies on a combination of biochemical and genomic methods. 3C and its derivatives (4C, 5C, Hi-C, Micro-C) detect interactions, while CRISPR-based approaches perturb them to test function.

The functional importance of enhancer-promoter interactions is demonstrated by developmental gene regulation and by disease-associated mutations that disrupt these interactions. Understanding these mechanisms is essential for interpreting the functional consequences of non-coding genomic variation.

## Frequently Asked Questions

### What is an enhancer-promoter interaction?

An enhancer-promoter interaction is a physical contact between a distal regulatory DNA element (enhancer) and the promoter of its target gene, brought about by the three-dimensional folding of chromatin. This contact allows the enhancer-bound proteins to activate transcription at the promoter.

### How do enhancers and promoters interact?

Enhancers and promoters interact through the formation of chromatin loops, which are created by the process of loop extrusion by cohesin. The loop brings the enhancer and promoter into close physical proximity, allowing protein-protein interactions between enhancer-bound transcription factors and coactivators and the promoter-bound basal transcription machinery.

### What methods are used to study enhancer-promoter interactions?

The primary methods are chromosome conformation capture (3C) and its derivatives, including 4C, 5C, Hi-C, and Micro-C. These methods detect physical proximity between genomic loci. CRISPR-based approaches, such as CRISPRi and CRISPRa, are used to perturb enhancers or promoters and test their functional significance.

### Why are enhancer-promoter interactions important?

Enhancer-promoter interactions are essential for the precise regulation of gene expression in development and in response to environmental signals. They allow genes to be activated by distal regulatory elements, and their disruption can cause disease, including developmental disorders and cancer.

### What is the looping model of enhancer-promoter interaction?

The looping model proposes that the intervening DNA between an enhancer and its target promoter is looped out, bringing the two elements into direct physical contact. This contact allows the enhancer-bound activation complex to directly interact with the promoter-bound transcription machinery.

### What role does CTCF play in enhancer-promoter interactions?

CTCF is an architectural protein that binds to specific DNA motifs and establishes the boundaries of topologically associating domains (TADs). It does not directly mediate enhancer-promoter contacts but rather constrains them by defining the regions within which enhancers and promoters can interact. CTCF also anchors cohesin-mediated loops.

### Can enhancer-promoter interactions be cell-type specific?

Yes. Enhancer-promoter interactions are highly cell-type specific. A given enhancer may contact its target promoter in one cell type but not in another, depending on the repertoire of transcription factors expressed and the chromatin state. This cell-type specificity is a major mechanism for achieving cell-type-specific gene expression.

## Key Takeaways

- Enhancer-promoter interactions are physical contacts between distal regulatory elements and their target promoters, mediated by chromatin looping.
- Chromatin is organized into TADs, which constrain enhancer-promoter interactions and prevent inappropriate cross-talk between regulatory elements.
- Transcription factors provide specificity, coactivators provide the functional output, and CTCF and cohesin provide the structural framework for loop formation.
- The looping model is the dominant mechanism for enhancer-promoter communication, but tracking and phase separation models may also contribute.
- 3C-based methods detect interactions, but CRISPR-based perturbation is required to establish functional significance.
- Enhancer-promoter interactions are dynamic, cell-type specific, and essential for developmental gene regulation; their disruption causes disease.
- Proximity does not equal function: an interaction detected by 3C must be validated by perturbation to demonstrate its role in gene regulation.

## Further Reading

- Yang JH, Hansen AS. *Enhancer selectivity in space and time: from enhancer-promoter interactions to promoter activation*. Nature reviews. Molecular cell biology. 2024. [PubMed 38413840](https://doi.org/10.1038/s41580-024-00710-6)
- Hamamoto K, Fukaya T. *Molecular architecture of enhancer-promoter interaction*. Current opinion in cell biology. 2022. [PubMed 35168174](https://doi.org/10.1016/j.ceb.2022.01.003)
- Gong H et al. *Computational methods for identifying enhancer-promoter interactions*. Quantitative biology (Beijing, China). 2023. [PubMed 41675661](https://doi.org/10.15302/J-QB-022-0322)
- Uyehara CM, Apostolou E. *3D enhancer-promoter interactions and multi-connected hubs: Organizational principles and functional roles*. Cell reports. 2023. [PubMed 37059094](https://doi.org/10.1016/j.celrep.2023.112068)
- Friedman MJ et al. *Enhancer-promoter specificity in gene transcription: molecular mechanisms and disease associations*. Experimental & molecular medicine. 2024. [PubMed 38658702](https://doi.org/10.1038/s12276-024-01233-y)
- van Arensbergen J, van Steensel B, Bussemaker HJ. *In search of the determinants of enhancer-promoter interaction specificity*. Trends in cell biology. 2014. [PubMed 25160912](https://doi.org/10.1016/j.tcb.2014.07.004)

## Related Topics

- [Enhancers and Promoters Differ](/knowledge/molecular-biology/enhancers-and-promoters-differ)
- [Gene Promoter vs Enhancer](/knowledge/molecular-biology/gene-promoter-vs-enhancer)
- [Operon Promoter](/knowledge/molecular-biology/operon-promoter)
- [Epigenetics vs Gene Environment Interaction](/knowledge/molecular-biology/epigenetics-vs-gene-environment-interaction)

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* [Nucleotide Formation: Biosynthesis and Assembly of DNA/RNA Building Blocks](/knowledge/molecular-biology/nucleotide-formation)