protein · BEGINNER LESSON

TDP-43

TDP-43 is a DNA/RNA-binding protein found mainly in the cell nucleus. It helps control RNA processing, including pre-mRNA splicing, mRNA transport, and localized translation, and its dysfunction is linked to neurodegenerative disease.

AI-assisted lesson · Public sources · Updated 2026-10-11

What TDP-43 is and what scientists measure

TDP-43, short for TAR DNA-binding protein of 43 kDa, is a protein that binds both DNA and RNA and is usually found in the nucleus, the compartment that contains most genetic material. Researchers measure where TDP-43 is located, whether it is aggregated or depleted from the nucleus, and whether RNA processing changes such as cryptic exon inclusion appear. These observations are used to study its normal role and its dysfunction in disease. [0,1,2]

[1] TDP-43: [GU]-ardian of the transcriptome [2] TDP-43 related amyotrophic lateral sclerosis-frontotemporal ... [3] TDP-43 in neurodegeneration and cancer: Decoding the mechanism of mRNA localization and translation - PubMed

How TDP-43 works in cells

In healthy cells, TDP-43 helps regulate pre-mRNA splicing, mRNA transport, and localized translation. Pre-mRNA is the first RNA copy made from DNA before it is edited into mature messenger RNA (mRNA). TDP-43 also represses cryptic exons, which are nonconserved RNA sequences that should usually stay out of the final message. Another described role is in the DNA damage response (DDR), the set of cellular steps that detect and repair DNA damage. [0,1,2]

What goes wrong in disease

The sources describe TDP-43 nuclear depletion, cytoplasmic aggregation, and mislocalization as common pathological features in affected neurons and glia in amyotrophic lateral sclerosis, frontotemporal dementia, and Alzheimer’s disease. When TDP-43 is depleted, mutated, or aggregated, cryptic exon repression can fail, DNA repair can be impaired, and genomic instability can increase. One review also reports that TDP-43 can bind damaged chromatin and help scaffold repair factors such as Ku70, XRCC4, and DNA ligase 4. [0,1,2]

Limits of the evidence

The sources are reviews and a systematic review of earlier studies, so they summarize evidence rather than reporting one single direct experiment. They also show that different models were used, including cell lines, patient-derived induced pluripotent stem (iPS) cells, organoids, rodent models, and post-mortem tissue. That means the findings are strong across many systems, but exact effects can vary by model and mutation. [1,2]

SEE THE IDEA

TDP-43 in healthy cells and disease

01Nucleus

Main location of TDP-43 in healthy cells.

02RNA processing

TDP-43 helps pre-mRNA splicing, mRNA transport, and localized translation.

03DNA repair

TDP-43 contributes to the DNA damage response and repair factor scaffolding.

04Disease change

Mislocalization, aggregation, or depletion disrupt these functions.

Healthy nuclear TDP-43 supports RNA processing and DNA repair; when it leaves the nucleus or aggregates, these functions are disrupted.

A simple flow from normal location to normal function to disease-associated disruption. [0,1,2]

TRY IT YOURSELF

Test your understanding

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0 of 3 questions answered

01 Which observation is most directly described as a marker of TDP-43 dysfunction?

02 A cell shows TDP-43 mostly outside the nucleus and forms cytoplasmic aggregates. What does the evidence suggest is likely affected?

03 Which statement best fits TDP-43 in healthy cells?

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Sources and further reading

This general lesson was generated from public source material. It explains a concept; it does not interpret a private paper or provide medical advice.

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