CS Gene

CS Gene

Overview

CS Gene

Overview

<table class="infobox infobox-gene">
<tr>
<th class="infobox-header" colspan="2">CS Gene</th>
</tr>
<tr>
<td class="label">Symbol</td>
<td>CS</td>
</tr>
<tr>
<td class="label">Full Name</td>
<td>Citrate Synthase</td>
</tr>
<tr>
<td class="label">Chromosomal Location</td>
<td>12p15</td>
</tr>
<tr>
<td class="label">NCBI Gene ID</td>
<td>1451</td>
</tr>
<tr>
<td class="label">Ensembl ID</td>
<td>ENSG00000143228</td>
</tr>
<tr>
<td class="label">UniProt ID</td>
<td>O75390</td>
</tr>
<tr>
<td class="label">OMIM</td>
<td>118950</td>
</tr>
<tr>
<td class="label">Aliases</td>
<td>CS, CS1</td>
</tr>
<tr>
<td class="label">KG Connections</td>
<td><a href="/atlas" style="color:#4fc3f7">1 edges</a></td>
</tr>
</table>

CS (Citrate Synthase) is a nuclear-encoded gene located on chromosome 12p15 that encodes citrate synthase, a key mitochondrial enzyme that catalyzes the first committed step of the citric acid cycle (TCA cycle). [@wortmann2019] Citrate synthase is essential for cellular energy metabolism, and its dysfunction has been implicated in Alzheimer's disease, Parkinson's disease, and other neurodegenerative conditions. [@yuan2022]

Gene Information

Protein Structure

Citrate synthase is a homodimeric enzyme, with each monomer consisting of approximately 466 amino acids: [@bridges2014]

Structural Features

• N-terminal domain: Contains the binding site for acetyl-CoA
• C-terminal domain: Contains the oxaloacetate binding site
• Active site: Located at the interface between the two domains
• Allosteric site: Located on the N-terminal domain for ATP/ADP regulation

Catalytic Mechanism

Citrate synthase follows an ordered bi-bi mechanism: [@valentino2020]

The reaction is essentially irreversible due to the favorable thermodynamics:
Acetyl-CoA + Oxaloacetate + H₂O → Citrate + CoA-SH + H⁺

Normal Function

TCA Cycle Role

Citrate synthase catalyzes the first committed step of the TCA cycle: [@wiegand2019]

• Reaction: Condensation of acetyl-CoA with oxaloacetate to form citrate
• Location: Mitochondrial matrix
• Enzyme class: EC 2.3.3.1 (acyl-CoA + acetyl-CoA C-acetyltransferase)

Regulation

Citrate synthase activity is tightly regulated: [@valentino2020]

• Substrate availability: Oxaloacetate and acetyl-CoA levels
• Product inhibition: Citrate acts as a feedback inhibitor
• Energy status: ATP inhibits, ADP activates
• Post-translational modifications: Phosphorylation, acetylation

Neuronal Relevance

In neurons, citrate synthase serves critical functions:

• Energy production: Provides NADH/FADH₂ for oxidative phosphorylation
• Lipid biosynthesis: Citrate is exported for fatty acid synthesis
• Metabolic signaling: Metabolite intermediates for biosynthetic pathways

Disease Associations

Alzheimer's Disease

Citrate synthase dysfunction is strongly linked to AD: [@maurer2000][@kim2022]

• Reduced CS activity: Post-mortem AD brains show 30-50% reduced CS activity
• Mitochondrial dysfunction: CS impairment contributes to bioenergetic failure
• Amyloid-beta toxicity: Aβ directly inhibits CS activity
• Energy crisis: Reduced CS contributes to neuronal hypometabolism

Parkinson's Disease

CS is affected in PD models and patients: [@liu2023][@yang2021]

• Reduced activity in substantia nigra: PD brains show decreased CS activity
• Alpha-synuclein interaction: CS activity inversely correlates with α-synuclein burden
• Mitochondrial complex I deficiency: CS dysfunction compounds ETC impairment
• Fibroblast biomarkers: CS activity reduced in PD patient-derived cells

Metabolic Disorders

• CS deficiency: Rare mitochondrial disorder causing myopathy and encephalopathy [@morais2018]
• Metabolic syndrome: CS variants associated with insulin resistance [@ferrari2021]

Aging

CS activity declines with normal aging: [@schmitt2023]

• Age-related decline in mitochondrial function
• Contributes to age-associated cognitive decline
• Enhanced by oxidative stress

Therapeutic Implications

Target for Neuroprotection

Citrate synthase is an emerging therapeutic target: [@park2022]

• Small molecule activators: Compounds that enhance CS activity
• Allosteric modulators: Targeting the ATP/ADP binding site
• Mitochondrial protection: Upstream interventions to preserve CS

Metabolite Supplementation

• Alpha-ketoglutarate: TCA cycle intermediate supplementation
• Oxaloacetate: Direct precursor for CS
• CoQ10: Supporting mitochondrial function alongside CS

Research Models

In Vitro Models

• Recombinant CS expression and purification
• Mitochondrial preparations from brain tissue
• Cell lines with CS knockdown/overexpression

Animal Models

• CS conditional knockout mice
• Transgenic CS overexpression
• AD/PD model crosses with CS modifiers

Patient-Derived Models

• iPSC-derived neurons from AD/PD patients
• Fibroblast bioenergetic profiling

Expression Pattern

Citrate synthase is expressed in virtually all tissues with high activity in:

• Heart: Highest expression (high energy demand)
• Liver: Central metabolic hub
• Kidney: Active metabolism
• Brain: Neurons and astrocytes
• Skeletal muscle: High mitochondrial content

• Neurons (particularly high in pyramidal neurons)
• [Astrocytes](/cell-types/astrocytes) Oligodendrocytes
• Microglia (lower levels)

Cross-References

• [CS Protein](/proteins/cs-protein)
• [TCA Cycle](/mechanisms/citric-acid-cycle)
• [Mitochondria](/mechanisms/mitochondria)
• [Alzheimer's Disease](/diseases/alzheimers-disease)
• [Parkinson's Disease](/diseases/parkinsons-disease)
• [Mitochondrial Dysfunction](/mechanisms/mitochondrial-dysfunction)

External Resources

• [NCBI Gene: CS](https://www.ncbi.nlm.nih.gov/gene/1451)
• [Ensembl: ENSG00000143228](https://www.ensembl.org/Homo_sapiens/Gene/Summary?g=ENSG00000143228)
• [UniProt: O75390](https://www.uniprot.org/uniprot/O75390)
• [OMIM: 118950](https://www.omim.org/entry/118950)

References

Pathway Diagram

The following diagram shows the key molecular relationships involving CS Gene discovered through SciDEX knowledge graph analysis: