HNRNPA1 - Heterogeneous Nuclear Ribonucleoprotein A1

HNRNPA1 - Heterogeneous Nuclear Ribonucleoprotein A1

Pathway Diagram

```mermaid
flowchart TD
HNRNPA1["HNRNPA1<br/>RNA-binding protein"]

ALS["ALS<br/>Amyotrophic Lateral Sclerosis"]
FTD["FTD<br/>Frontotemporal Dementia"]
MS["Multiple Sclerosis"]
NEURO["Neurodegeneration"]

VCP["VCP<br/>Valosin-containing protein"]
TIA1["TIA1<br/>T-cell intracellular<br/>antigen 1"]

ALOX15["ALOX15<br/>Arachidonate<br/>15-lipoxygenase"]
FERROPTOSIS["Ferroptosis<br/>Iron-dependent<br/>cell death"]
LIPID_MET["Lipid Metabolism"]

AUTOPHAGY["Autophagy<br/>Cellular clearance"]
IMMUNITY["Innate Immunity<br/>Immune response"]

USP7["USP7<br/>Ubiquitin-specific<br/>peptidase 7"]

HNRNPA1 -->|"activates"| ALS
HNRNPA1 -->|"associated_with"| FTD
HNRNPA1 -->|"activates"| MS
HNRNPA1 -->|"activates"| NEURO

HNRNPA1 -->|"associated_with"| VCP
HNRNPA1 -->|"associated_with"| TIA1

HNRNPA1 -->|"inhibits"| ALOX15
ALOX15 -->|"promotes"| FERROPTOSIS
HNRNPA1 -->|"inhibits"| FERROPTOSIS
HNRNPA1 -->|"inhibits"| LIPID_MET

HNRNPA1 -->|"expressed_in"| AUTOPHAGY
HNRNPA1 -->|"activates"| IMMUNITY

HNRNPA1 -->|"inhibits"| USP7

FERROPTOSIS -->|"contributes_to"| NEURO
AUTOPHAGY -->|"dysregulated_in"| ALS
VCP -->|"mutations_cause"| FTD

style HNRNPA1 fill:#006494
style ALS fill:#ef5350
style FTD fill:#ef5350
style MS fill:#ef5350
style NEURO fill:#ef5350
style VCP fill:#4a1a6b
style TIA1 fill:#4a1a6b
style ALOX15 fill:#4a

HNRNPA1 - Heterogeneous Nuclear Ribonucleoprotein A1

Pathway Diagram

<table class="infobox infobox-gene">
<tr>
<th class="infobox-header" colspan="2">HNRNPA1 — Heterogeneous Nuclear Ribonucleoprotein A1</th>
</tr>
<tr> [@rna2013]
<td class="label">Symbol</td> [@stress2019]
<td><strong>HNRNPA1</strong></td> [@liquidliquid2019]
</tr>
<tr>
<td class="label">Full Name</td>
<td>Heterogeneous Nuclear Ribonucleoprotein A1</td>
</tr>
<tr>
<td class="label">Chromosome</td>
<td>12q13.13</td>
</tr>
<tr>
<td class="label">NCBI Gene</td>
<td><a href="https://www.ncbi.nlm.nih.gov/gene/3178" target="_blank">3178</a></td>
</tr>
<tr>
<td class="label">Ensembl</td>
<td><a href="https://ensembl.org/Homo_sapiens/Gene/Summary?g=ENSG00000166086" target="_blank">ENSG00000166086</a></td>
</tr>
<tr>
<td class="label">OMIM</td>
<td><a href="https://omim.org/entry/164017" target="_blank">164017</a></td>
</tr>
<tr>
<td class="label">UniProt</td>
<td><a href="https://www.uniprot.org/uniprot/P09651" target="_blank">P09651</a></td>
</tr>
<tr>
<td class="label">Diseases</td>
<td>[Amyotrophic Lateral Sclerosis](/diseases/amyotrophic-lateral-sclerosis), [Frontotemporal Dementia](/diseases/frontotemporal-dementia), [Inclusion Body Myopathy](/diseases/inclusion-body-myopathy)</td>
</tr>
<tr>
<td class="label">Expression</td>
<td>Ubiquitous, high in brain and muscle</td>
</tr>
<tr>
<td class="label">Associated Diseases</td>
<td><a href="/wiki/als" style="color:#ef9a9a">ALS</a>, <a href="/wiki/aging" style="color:#ef9a9a">Aging</a>, <a href="/wiki/als" style="color:#ef9a9a">Als</a>, <a href="/wiki/alzheimer" style="color:#ef9a9a">Alzheimer</a>, <a href="/wiki/amyotrophic-lateral-sclerosis" style="color:#ef9a9a">Amyotrophic Lateral Sclerosis</a></td>
</tr>
<tr>
<td class="label">KG Connections</td>
<td><a href="/atlas" style="color:#4fc3f7">222 edges</a></td>
</tr>
</table>

HNRNPA1 — Heterogeneous Nuclear Ribonucleoprotein A1

Introduction

Hnrnpa1 Heterogeneous Nuclear Ribonucleoprotein A1 is an important component in the neurobiology of neurodegenerative diseases. This page provides detailed information about its structure, function, and role in disease processes.

Overview

HNRNPA1 (Heterogeneous Nuclear Ribonucleoprotein A1) is a gene located on chromosome 12q13.13 that encodes an abundant RNA-binding protein with critical roles in RNA processing, splicing, and transport [1](https://pubmed.ncbi.nlm.nih.gov/12445353/). The gene is catalogued as NCBI Gene ID [3178](https://www.ncbi.nlm.nih.gov/gene/3178) and OMIM [164017](https://omim.org/entry/164017). HNRNPA1 is a member of the heterogeneous ribonucleoprotein (hnRNP) family, which are nuclear proteins that bind pre-mRNA and regulate various aspects of RNA metabolism.

HNRNPA1 is ubiquitously expressed with high levels in the brain and muscle. The protein contains two RNA recognition motifs (RRMs) and a prion-like domain that enables liquid-liquid phase separation (LLPS) and stress granule formation. Pathogenic mutations in HNRNPA1 cause [amyotrophic lateral sclerosis](/diseases/amyotrophic-lateral-sclerosis) (ALS), [frontotemporal dementia](/diseases/frontotemporal-dementia) (FTD), and inclusion body myopathy, linking RNA metabolism dysregulation to neurodegenerative disease [2](https://pubmed.ncbi.nlm.nih.gov/21358643/).

Protein Structure and Function

Domain Architecture

HNRNPA1 contains several functional domains:

Alternative Splicing Regulation

HNRNPA1 is a key splicing regulator that:

• Promotes exon skipping by antagonizing splicing factors
• Regulates alternative splicing of specific transcripts
• Controls splicing of its own pre-mRNA (autoregulation)
• Modulates tissue-specific splicing patterns

• Pyruvate kinase M1/2 (PKM1/PKM2) switching
• [Tau](/proteins/tau) exon 10 splicing
• Synaptic protein isoforms

RNA Transport and Localization

HNRNPA1 participates in RNA transport to dendritic and axonal compartments:

• Binds to 3' untranslated regions (UTRs) of target mRNAs
• Forms ribonucleoprotein complexes for dendritic RNA localization
• Regulates local translation at synapses

Pathological Mechanisms in Neurodegeneration

Stress Granule Dynamics

One of the key pathogenic mechanisms involves dysregulated stress granule biology:

• Increased tendency to form solid aggregates
• Impaired stress granule dynamics
• Persistent cytoplasmic inclusions [2](https://pubmed.ncbi.nlm.nih.gov/21358643/)

RNA Metabolism Defects

Mutant HNRNPA1 causes widespread RNA processing defects:

• Altered splicing of neuronal transcripts
• Impaired RNA export from nucleus
• Dysregulated microRNA biogenesis
• Defects in translation regulation

Protein Aggregation

HNRNPA1 mutations promote formation of:

• Cytoplasmic inclusions in motor [neurons](/entities/neurons)
• Nuclear inclusions in muscle cells
• Co-aggregation with other RNA-binding proteins

Disease Associations

Amyotrophic Lateral Sclerosis (ALS)

HNRNPA1 mutations cause familial ALS through dominant toxic gain-of-function mechanisms:

• D262V mutation: Disrupts LLPS, promotes aggregation
• P288L mutation: Alters stress granule dynamics
• G298S mutation: Affects RNA binding affinity

• Progressive motor neuron loss
• Muscle weakness and atrophy
• Spasticity
• Typically adult onset [4](https://pubmed.ncbi.nlm.nih.gov/29154390/)

Frontotemporal Dementia (FTD)

HNRNPA1 mutations also cause FTD, often with overlapping ALS features:

• Behavioral variant FTD
• Language variant (primary progressive aphasia)
• Often shares pathological features with ALS (TDP-43 pathology)

Inclusion Body Myopathy (IBM)

Mutations cause autosomal dominant inclusion body myopathy:

• Progressive muscle weakness
• Rimmed vacuoles in muscle fibers
• Often associated with Paget's disease of bone

Multisystem Proteinopathy (MSP)

HNRNPA1 is one of several genes (including HNRNPA2B1, VCP, SQSTM1) causing multisystem proteinopathy, a syndrome featuring:

• Inclusion body myopathy
• Paget's disease of bone
• Frontotemporal dementia
• [ALS](/diseases/amyotrophic-lateral-sclerosis)

Therapeutic Implications

Targets

Challenges

• HNRNPA1 has essential normal functions; complete inhibition is toxic
• Mutations cause gain-of-function; reduction may help but timing is critical
• Multiple RNA-binding proteins involved; specificity is challenging

See Also

• [HNRNPA1 Protein](/hnrnpa1-protein)
• [RNA Metabolism](/mechanisms/rna-metabolism)
• [Stress Granules](/mechanisms/stress-granules)
• [Amyotrophic Lateral Sclerosis](/diseases/amyotrophic-lateral-sclerosis)
• [Frontotemporal Dementia](/diseases/frontotemporal-dementia)
• [TDP-43 Proteinopathy](/mechanisms/tdp-43-proteinopathy)
• [Liquid-Liquid Phase Separation](/mechanisms/liquid-liquid-phase-separation)

External Links

• [NCBI Gene: HNRNPA1](https://www.ncbi.nlm.nih.gov/gene/3178)
• [UniProt: HNRNPA1 (P09651)](https://www.uniprot.org/uniprot/P09651)
• [Ensembl: HNRNPA1](https://ensembl.org/Homo_sapiens/Gene/Summary?g=ENSG00000166086)
• [OMIM: HNRNPA1](https://omim.org/entry/164017)

Background

The study of Hnrnpa1 Heterogeneous Nuclear Ribonucleoprotein A1 has evolved significantly over the past decades. Research in this area has revealed important insights into the underlying mechanisms of neurodegeneration and continues to drive therapeutic development.

Historical context and key discoveries in this field have shaped our current understanding and will continue to guide future research directions.

Brain Atlas Resources

• [Allen Human Brain Atlas - HNRNPA1 Expression](https://human.brain-map.org/microarray/search/show?search_term=HNRNPA1): Gene expression data from the Allen Human Brain Atlas
• [BrainSpan Atlas of the Developing Human Brain](https://brainspan.org/static/download.html): Developmental expression data for HNRNPA1

References

Pathway Diagram

The following diagram shows the key molecular relationships involving HNRNPA1 - Heterogeneous Nuclear Ribonucleoprotein A1 discovered through SciDEX knowledge graph analysis: