The ELOVL7 gene (Elongation of Very Long Chain Fatty Acids 7) encodes a member of the ELOVL family of enzymes responsible for the first and rate-limiting step of very-long-chain fatty acid (VLCFA) elongation. VLCFAs (≥22 carbons) are essential components of neuronal membranes, myelin sheaths, and play important roles in brain function and neurodegenerative diseases.
| ELOVL7 Gene |
|---|
| Gene Symbol | ELOVL7 |
| Full Name | Elongation of Very Long Chain Fatty Acids 7 |
| Chromosomal Location | 5p12 |
| NCBI Gene ID | [199870](https://www.ncbi.nlm.nih.gov/gene/199870) |
| Ensembl ID | ENSG00000164181 |
| UniProt ID | [Q9H5Q3](https://www.uniprot.org/uniprot/Q9H5Q3) |
| Protein Size | 299 amino acids |
¶ Protein Structure and Function
The ELOVL7 gene is located on chromosome 5p12 and encodes a 299-amino acid membrane-bound enzyme in the endoplasmic reticulum. The protein contains multiple transmembrane domains and a conserved HXXHH motif essential for catalytic activity.
ELOVL7 shows highest expression in:
- Liver - Primary site of fatty acid metabolism
- Brain - Neurons and glia
- Kidney - Steroid hormone synthesis
- Heart - Cardiac metabolism
- Adipose tissue - Lipid storage
- Substrate binding - VLCFA precursors (C16-C20)
- Condensation - Condenses malonyl-CoA with fatty acyl-CoA
- Reduction - Two NADPH-dependent reductions
- Chain elongation - Adds 2 carbons per cycle
- Product release - Releases elongated fatty acid
- Preferred substrates - C16:0, C18:0, C18:1, C18:2, C20:4
- Products - C22-C26 fatty acids
- Specialization - Prefers saturated and monounsaturated fatty acids
- Membrane composition - Altered VLCFA metabolism in AD brains
- Amyloid processing - Lipid rafts affected by fatty acid composition
- Cognitive decline - Correlations with disease progression
- Therapeutic potential - Targeting VLCFA metabolism
- Mitochondrial function - Lipid metabolism affects mitochondrial membranes
- Alpha-synuclein - Lipid interactions with α-syn aggregates
- Neuroprotection - Potential therapeutic targeting
- Multiple sclerosis - Myelin VLCFA content
- Epilepsy - Altered fatty acid metabolism
- Stroke - Ischemia affects lipid metabolism
- Insulin resistance - ELOVL7 in metabolic syndrome
- Dyslipidemia - Altered VLCFA levels
- Cardiovascular disease - Atherosclerosis connections
- Enzyme inhibitors - Modulate VLCFA synthesis
- Substrate supplementation - Dietary interventions
- Gene therapy - AAV-mediated expression
- Biomarkers - VLCFA levels as disease markers
- Drug development - Selective ELOVL7 modulators
- Combination therapy - Multi-target approaches
The ELOVL (Elongation of Very Long Chain Fatty Acids) family performs the first and rate-limiting step of fatty acid elongation. ELOVL7 specifically catalyzes the condensation reaction:
flowchart TD
A["Fatty acyl-CoA<br/>C16-C20"] --> B["Condensation"]
B --> C["Add 2 carbons<br/>via malonyl-CoA"]
C --> D["β-Keto reduction"]
D --> E["NADPH"]
E --> F["β-Hydroxyacyl reduction"]
F --> G["NADPH"]
G --> H["Very long chain fatty acid<br/>C22-C26"]
The reaction proceeds through four enzymatic steps repeated cyclically:
- Condensation: Malonyl-CoA adds two carbons to the fatty acyl-CoA substrate
- β-Keto reduction: NADPH reduces the β-keto group to a hydroxyl group
- Dehydration: Removal of water creates a trans-2-enoyl intermediate
- Enoyl reduction: NADPH reduces the double bond to produce the elongated fatty acid
ELOVL7 exhibits distinct substrate preferences:
| Substrate Category |
Specific Fatty Acids |
Product Range |
| Saturated |
C16:0 (palmitoyl), C18:0 (stearoyl) |
C22:0, C24:0 |
| Monounsaturated |
C16:1, C18:1 (oleoyl) |
C22:1, C24:1 |
| Polyunsaturated |
C18:2 (linoleoyl), C20:4 (arachidonoyl) |
C20-C24PUFAs |
¶ Membrane Microdomains
Very long chain fatty acids are enriched in lipid rafts—cholesterol-rich membrane microdomains critical for:
- Signal transduction: Concentrating receptors and signaling molecules
- Membrane trafficking: Facilitating vesicular transport
- Protein sorting: Localizing proteins to specific membrane regions
Altered VLCFA metabolism affects lipid raft composition in several ways:
- Amyloid processing: Lipid raft cholesterol levels influence amyloid precursor protein (APP) processing and Aβ generation
- Tau phosphorylation: Membrane lipid composition affects tau kinase/phosphatase balance
- Synaptic function: Presynaptic terminals are highly enriched in VLCFAs
- Myelin integrity: Oligodendrocyte myelin requires specific VLCFA profiles
Neurons have particularly high requirements for VLCFAs:
- Synaptic vesicle membranes: Highly enriched in C22-C24 fatty acids
- Mitochondrial membranes: VLCFA content affects membrane fluidity and function
- Myelin sheaths: Essential for rapid saltatory conduction
| Cell Type |
VLCFA Role |
| Oligodendrocytes |
Myelin sheath formation and maintenance |
| Astrocytes |
Lipid transport to neurons |
| Microglia |
Inflammatory lipid mediator synthesis |
Several approaches for targeting ELOVL7 therapeutically:
| Strategy |
Compound Type |
Development Status |
| Substrate analogs |
Competitive inhibitors |
Preclinical |
| Antibody-based |
Neutralizing antibodies |
Research |
| Gene silencing |
Antisense oligonucleotides |
Discovery |
| Dietary modification |
Substrate deprivation |
Clinical |
VLCFA levels in biological fluids may serve as biomarkers:
- Plasma VLCFAs: Correlate with disease progression in AD/PD
- Cerebrospinal fluid: May reflect brain lipid metabolism
- Tissue biopsies: Direct measurement of VLCFA content