PANK2 — Pantothenate Kinase 2
<table class="infobox infobox-gene">
<tr>
<th class="infobox-header" colspan="2">PANK2 — Pantothenate Kinase 2</th>
</tr>
<tr>
<td class="label">Symbol</td>
<td><strong>PANK2</strong></td>
</tr>
<tr>
<td class="label">Full Name</td>
<td>Pantothenate Kinase 2</td>
</tr>
<tr>
<td class="label">Chromosome</td>
<td>20p13</td>
</tr>
<tr>
<td class="label">NCBI Gene</td>
<td><a href="https://www.ncbi.nlm.nih.gov/gene/80025" target="_blank">80025</a></td>
</tr>
<tr>
<td class="label">Ensembl</td>
<td><a href="https://ensembl.org/Homo_sapiens/Gene/Summary?g=ENSG00000125779" target="_blank">ENSG00000125779</a></td>
</tr>
<tr>
<td class="label">OMIM</td>
<td><a href="https://omim.org/entry/606157" target="_blank">606157</a></td>
</tr>
<tr>
<td class="label">UniProt</td>
<td><a href="https://www.uniprot.org/uniprot/Q9C0B0" target="_blank">Q9C0B0</a></td>
</tr>
<tr>
<td class="label">Diseases</td>
<td>[Pantothenate Kinase-Associated Neurodegeneration](/diseases/pank)</td>
</tr>
<tr>
<td class="label">Expression</td>
<td>High in brain, especially basal ganglia</td>
</tr>
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<th class="infobox-subheader" colspan="2">Key Mutations</th>
</tr>
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<td colspan="2" style="font-size:0.85em">G521R<br>A628P<br>V464M<br>D378G<br>R441P</td>
</tr>
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<td class="label">Associated Diseases</td>
<td><a href="/wiki/aging" style="color:#ef9a9a">Aging</a>, <a href="/wiki/als" style="color:#ef9a9a">Als</a>, <a href="/wiki/dystonia" style="color:#ef9a9a">Dystonia</a>, <a href="/wiki/ms" style="color:#ef9a9a">Ms</a>, <a href="/wiki/neurodegeneration" style="color:#ef9a9a">Neurodegeneration</a></td>
</tr>
<tr>
<td class="label">KG Connections</td>
<td><a href="/atlas" style="color:#4fc3f7">28 edges</a></td>
</tr>
</table>
PANK2 — Pantothenate Kinase 2
Introduction
Pank2 — Pantothenate Kinase 2 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
Mermaid diagram (expand to render)
PANK2 (Pantothenate Kinase 2) is a gene located on chromosome 20p13 that encodes a mitochondrial enzyme essential for coenzyme A (CoA) biosynthesis. Mutations in PANK2 cause a devastating neurodegenerative disorder called pantothenate kinase-associated neurodegeneration (PKAN), formerly known as Hallervorden-Spatz syndrome. This autosomal recessive disorder is characterized by progressive movement disorders, including dystonia, parkinsonism, and spasticity, along with iron accumulation in the brain. The identification of PANK2 as the causative gene in 2001 provided insight into the pathogenesis of PKAN and revealed the critical importance of CoA metabolism in neuronal survival.
The PANK2 protein is a 570-amino acid enzyme localized to the mitochondrial matrix. It catalyzes the first and rate-limiting step in CoA biosynthesis, the phosphorylation of vitamin B5 (pantothenate) to phosphopantothenate. This reaction is essential because CoA serves as an essential cofactor for over 100 enzymatic reactions, including fatty acid metabolism, amino acid catabolism, and energy production. The brain has particularly high CoA requirements due to its high metabolic activity and lipid content.
Normal Physiological Function
Pantothenate kinase 2 is the rate-limiting enzyme in the CoA biosynthesis pathway, catalyzing the ATP-dependent phosphorylation of pantothenate (vitamin B5) to phosphopantothenate. This reaction occurs in mitochondria, and PANK2 is one of four human pantothenate kinase isoforms with distinct tissue distributions and subcellular localizations. PANK2 is the predominant isoform in the brain and is specifically localized to mitochondria, where CoA synthesis primarily occurs.
CoA is essential for cellular metabolism in all tissues, but [neurons](/entities/neurons) have particularly high requirements due to their reliance on oxidative phosphorylation and lipid metabolism. CoA is also required for the synthesis of [acetylcholine](/entities/acetylcholine), the major neurotransmitter, and for protein acetylation modifications that regulate gene expression. Disruption of CoA homeostasis therefore has profound effects on neuronal function and survival.
In addition to its enzymatic function, PANK2 may have roles in mitochondrial quality control and iron metabolism. Studies suggest that CoA deficiency can lead to iron dysregulation, which may explain the iron accumulation observed in PKAN patients. The protein may also interact with proteins involved in mitochondrial dynamics and mitophagy.
Brain Expression Patterns
PANK2 is highly expressed in the brain, with particularly high levels in the basal ganglia, including the globus pallidus and substantia nigra. This pattern of expression corresponds to the brain regions most affected in PKAN, where iron accumulation and neurodegeneration are most severe. The protein is also expressed in other brain regions, including the [cortex](/brain-regions/cortex) and [hippocampus](/brain-regions/hippocampus).
The Allen Human Brain Atlas confirms high PANK2 expression in the basal ganglia and reveals expression in both neurons and glial cells. Mitochondrial localization of PANK2 is essential for its function, and the protein contains an N-terminal mitochondrial targeting sequence that directs it to the mitochondrial matrix.
Disease Associations
PANK2 mutations cause pantothenate kinase-associated neurodegeneration (PKAN), a rare autosomal recessive disorder characterized by progressive neurodegeneration with iron accumulation. PKAN is part of a group of disorders called neuroaxonal dystrophy and is classified into two forms: classic PKAN with early onset (typically before age 10) and atypical PKAN with later onset (typically in the second or third decade).
Classic PKAN presents in childhood with gait disturbance, dystonia, and spasticity. Progressive motor decline leads to loss of ambulation within a few years of onset. Cognitive impairment is common, and some patients develop pigmentary retinopathy and other systemic features. The disease is usually rapidly progressive, with death typically occurring in the second or third decade.
Atypical PKAN has later onset and slower progression. Patients present in adolescence or early adulthood with speech difficulties, psychiatric symptoms, and mild motor impairment. The disease course is more indolent, with patients often surviving into middle age or later.
Key Mutations
Over 100 pathogenic mutations have been identified in PANK2, including missense, nonsense, and splice-site mutations. Most mutations cause loss of enzymatic function, consistent with the recessive inheritance pattern. The most common mutation is G521R, which affects a residue critical for ATP binding and catalysis.
The A628P mutation is another common variant that causes classic PKAN with early onset. This mutation severely impairs enzymatic activity, leading to near-complete loss of PANK2 function. The V464M and D378G mutations cause atypical PKAN with later onset and slower progression, suggesting that some residual enzyme activity is preserved.
Genotype-phenotype correlations are imperfect, suggesting that modifier genes or environmental factors influence disease expression. Some patients with two null mutations have relatively mild disease, while others with potentially hypomorphic mutations have severe presentations.
Therapeutic Targeting
Treatment for PKAN is primarily supportive and includes movement disorder management, physical therapy, and nutritional support. The CoA precursor pantethine has been tested as a potential therapy based on the hypothesis that it might bypass the blocked step in CoA biosynthesis. Early treatment with pantethine may slow disease progression in some patients, particularly if initiated before significant neurodegeneration occurs.
Gene therapy approaches using viral vectors to deliver functional PANK2 are in development. These therapies aim to restore PANK2 function in affected neurons, potentially halting or reversing disease progression. Small molecule therapies targeting CoA metabolism or iron chelation are also under investigation.
External Links
- NCBI Gene: [PANK2 Gene Page](https://www.ncbi.nlm.nih.gov/gene/80025)
- Ensembl: [PANK2 Gene Summary](https://ensembl.org/Homo_sapiens/Gene/Summary?g=ENSG00000125779)
- OMIM: [PANK2 Entry 606157](https://omim.org/entry/606157)
- UniProt: [PANK2 (Q9C0B0)](https://www.uniprot.org/uniprot/Q9C0B0)
- NBIA Disorders Alliance: [PKAN Information](https://nbiausa.org/)
See Also
- [Genes Index](/genes)
- [Proteins Index](/proteins)
- [Pantothenate Kinase-Associated Neurodegeneration](/diseases/pantothenate-kinase-associated-neurodegeneration-pkan)
- [Iron Metabolism](/mechanisms/iron-metabolism-neurodegeneration)
- [Coenzyme A](/mechanisms/coenzyme-a-metabolism)
Brain Atlas Resources
- [Allen Brain Atlas](https://brain-map.org)
- [Allen Human Brain Atlas: PANK2 search](https://human.brain-map.org/microarray/search/show?search_term=PANK2)
- [Allen Mouse Brain Atlas: PANK2 search](https://mouse.brain-map.org/search/index.html?query=PANK2)
- [Allen Cell Type Atlas](https://portal.brain-map.org/atlases-and-data/rnaseq)
- [BrainSpan Developmental Transcriptome](https://www.brainspan.org)
Background
The study of Pank2 — Pantothenate Kinase 2 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.
References
[Zhou B, et al, Mutations in PANK2 cause neurodegeneration with brain iron accumulation (2009)](https://doi.org/10.1093/brain/awp098)
[Hayflick SJ, Pantothenate kinase-associated neurodegeneration (2013)](https://doi.org/10.1001/jamaneurol.2013.4889)
[Leonardi R, et al, Coenzyme A metabolism and neurodegeneration (2021)](https://doi.org/10.1016/j.jbc.2021.100720)
Unknown, Page last updated: 2026-03-01. (2026)Pathway Diagram
The following diagram shows the key molecular relationships involving PANK2 — Pantothenate Kinase 2 discovered through SciDEX knowledge graph analysis:
Mermaid diagram (expand to render)