Researchers discover a hidden 'mini metabolism' operating directly on human DNA

Overview

Updated May 30

For decades, biologists treated the cell's energy-producing and DNA-reading machinery as separate systems operating in separate compartments. A study published March 6 in Nature Communications upends that assumption.

More than 200 metabolic enzymes, many normally associated with mitochondrial energy production, are physically attached to human DNA inside the nucleus. About 7% of all proteins bound to chromatin are metabolic enzymes. The researchers describe this collective system as a 'mini metabolism' within the nucleus itself.

The finding matters because tissue and cancer types display distinct patterns of nuclear enzymes—what the team calls 'nuclear metabolic fingerprints.' Oxidative phosphorylation enzymes, for instance, are abundant on the chromatin of breast cancer cells but largely absent from lung cancer cells. That tissue-specific variation opens a new front for cancer diagnostics and targeted therapies, and raises a fundamental question: how do enzymes far too large for the nucleus's usual import channels get inside?

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Key Indicators

200+

Metabolic enzymes found on DNA

Enzymes normally associated with energy production, now confirmed as physically bound to chromatin inside the nucleus.

Chromatin-bound proteins that are metabolic

Roughly one in fourteen proteins attached to the DNA-protein complex are metabolic enzymes, far more than previously assumed.

Cancer cell lines profiled

The study analyzed 44 cancer cell lines and 10 healthy cell types across 10 different tissues.

Tissue types studied

Healthy cell types from 10 distinct tissues were profiled, each showing unique nuclear enzyme patterns.

Voices

Curated perspectives — historical figures and your fellow readers.

Charles Darwin

(1809-1882) · Victorian Era · science

Fictional AI pastiche — not real quote.

"How remarkable that Nature, ever economical in her designs, should employ the same metabolic machinery for two great purposes — yet how much more remarkable that we required nearly two centuries after my own humble observations to discover she had hidden one workshop inside another. The cell, it would seem, is as reluctant to surrender its deepest secrets as my colleagues were to accept natural selection — though I confess the nucleus concealing entire enzymatic assemblies of such considerable dimensions strikes me as rather more audacious than anything I witnessed among the finches of the Galápagos."

Ever wondered what historical figures would say about today's headlines?

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People Involved

Sara Sdelci

Group Leader and corresponding author, Centre for Genomic Regulation (CRG), Barcelona

Leading ongoing research into chromatin metabolism and cancer

Savvas Kourtis

First author of the chromatome profiling study

Researcher at the Centre for Genomic Regulation

Organizations Involved

Centre for Genomic Regulation (CRG)

Research Institute

Home institution for the nuclear metabolic fingerprint discovery

An international biomedical research center in Barcelona focused on understanding the complexity of life from the genome to the cell to whole organisms.

Timeline

1920s March 2026

6 events Latest: March 6th, 2026 · 6 months ago

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March 2026
Peer-reviewed study published in Nature Communications
Latest Publication

The team published native chromatome profiling results in Nature Communications, revealing over 200 metabolic enzymes on DNA across 44 cancer cell lines and 10 healthy cell types, establishing the concept of a nuclear metabolic fingerprint.
March 6th, 2026
December 2023
Chromatome profiling preprint posted on bioRxiv
Publication

Kourtis, Sdelci, and colleagues posted a preprint describing comprehensive chromatome profiling across cancer lineages and healthy samples, identifying widespread metabolic enzyme presence on chromatin.
December 6th, 2023
2019
Sdelci lab established with ERC grant to study chromatin metabolism
Research

Sara Sdelci joined the Centre for Genomic Regulation in Barcelona and received a European Research Council Starting Grant to investigate the role of metabolic enzymes on chromatin in cancer.
2019
2016
Review establishes 'moonlighting' enzyme concept
Publication

A review in Trends in Biochemical Sciences documented how metabolic enzymes can perform non-metabolic functions in the nucleus, coining the term 'moonlighting' for this dual role.
2016
1950s
First reports of glycolytic enzymes in the nucleus
Discovery

Researchers first observed glycolytic enzymes inside the cell nucleus, though these findings were not widely pursued for decades.
1950s
1920s
Otto Warburg observes altered metabolism in tumors
Discovery

German physiologist Otto Warburg discovered that tumor cells consume far more glucose than surrounding tissue and ferment it to lactate even in the presence of oxygen, a phenomenon later named the Warburg effect.
1920s

Historical Context

3 moments from history that rhyme with this story — and how they unfolded.

1923-1930s

The Warburg Effect (1920s)

Otto Warburg, a German physiologist, discovered that cancer cells consume enormous amounts of glucose and ferment it to lactate even when oxygen is available, unlike normal cells. He published his first paper on this observation in 1923 and won the Nobel Prize in Physiology or Medicine in 1931 for related work on respiratory enzymes.

Then

The scientific community acknowledged the observation but largely set it aside, as the molecular tools to investigate it did not yet exist.

Now

It took roughly 80 years for the Warburg effect to drive drug development. Today, the PET scan, which detects tumors by their elevated glucose uptake, is one of oncology's most important diagnostic tools, and cancer metabolism is a major therapeutic target.

Why this matters now

The nuclear metabolic fingerprint discovery follows the same arc: a fundamental observation about how cancer cells handle energy differently. The Warburg effect shows both the potential payoff and the long timeline between metabolic discovery and clinical impact.

1983-2004

Discovery of epigenetic modifications and cancer (1980s-2000s)

Starting with the discovery of abnormal DNA methylation in cancer cells in 1983, researchers gradually established that chemical modifications on DNA and its packaging proteins could activate or silence genes without changing the DNA sequence itself. By 2004, the first epigenetic drug, azacitidine, received approval from the Food and Drug Administration for treating myelodysplastic syndromes.

Then

The epigenetics field grew rapidly, with dozens of labs identifying new modifications and their roles in cancer progression.

Now

Epigenetic drugs are now a multi-billion-dollar therapeutic class, and epigenetic biomarkers are used in cancer screening tests like the Epi proColon blood test for colorectal cancer.

Why this matters now

Nuclear metabolic enzymes may represent a new layer of regulation sitting at the intersection of metabolism and epigenetics. If these enzymes modify chromatin function, they could expand the druggable targets in epigenetic cancer therapy.

September 2012

The ENCODE Project reveals 'junk DNA' is functional (2012)

The Encyclopedia of DNA Elements project, a consortium of 442 scientists, published 30 papers simultaneously showing that at least 80% of the human genome previously dismissed as 'junk DNA' actually serves biochemical functions, including gene regulation. The finding overturned a decades-old assumption that most DNA was useless.

Then

The results sparked intense debate about the definition of 'functional' and reshaped how researchers studied non-coding regions of the genome.

Now

ENCODE's regulatory maps became essential infrastructure for understanding disease-linked genetic variants and enabled new approaches to gene therapy and precision medicine.

Why this matters now

Like ENCODE revealed hidden function in DNA once called junk, the chromatome study reveals hidden function in enzymes once thought to operate only outside the nucleus. Both discoveries expanded the map of what cells actually do with their molecular machinery.