The Function of APOA1
Participates in the reverse transport of cholesterol from tissues to the liver for excretion by promoting cholesterol efflux from tissues and by acting as a cofactor for the lecithin cholesterol acyltransferase (LCAT). As part of the SPAP complex, activates spermatozoa motility.
Protein names
Recommended name:
Apolipoprotein A-IAlternative name(s):
Apo-AIApoA-I
Apolipoprotein A1
ProapoA-I
Apolipoprotein A-I(1-242
- RS12721025 (APOA1) ??
- RS5069 (APOA1) ??
- RS670 (APOA1) ??
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Top Gene-Substance Interactions
APOA1 Interacts with These Diseases
| Disease | Score |
Substances That Increase APOA1
| Substances | Interaction | Organism | Category |
Substances That Decrease APOA1
| Substances | Interaction | Organism | Category |
Advanced Summary
familial HDL deficiency Mutations in the APOA1 gene cause familial HDL deficiency, an inherited condition characterized by low levels of HDL in the blood and an elevated risk for early-onset cardiovascular disease, which often occurs before age 50. These mutations lead to an altered apoA-I protein. Some versions of the altered protein are less able to promote the removal of cholesterol and phospholipids from cells, which decreases the amount of these substances available to form HDL. Other versions of the altered protein are less able to stimulate cholesterol esterification, which means cholesterol cannot be integrated into HDL particles. Both types of mutation result in low HDL levels. A shortage (deficiency) of HDL is believed to increase the risk of cardiovascular disease. other disorders Mutations in the APOA1 gene can also cause a condition called familial visceral amyloidosis, which is characterized by an abnormal accumulation of proteins (amyloidosis) in internal organs (viscera). The mutations that cause this condition alter the apoA-I protein. Abnormal apoA-I proteins stick together to form amyloid deposits that impair the function of the affected organs. The liver, kidneys, and heart are commonly affected by amyloidosis. Depending on the organs involved, the signs and symptoms of the condition vary. Affected individuals can have an enlarged liver (hepatomegaly), chronic kidney disease, or a form of heart disease called cardiomyopathy. However, in some people, the condition is very mild and causes no apparent signs or symptoms.
The APOA1 gene provides instructions for making a protein called apolipoprotein A-I (apoA-I). ApoA-I is a component of high-density lipoprotein (HDL). HDL is a molecule that transports cholesterol and certain fats called phospholipids through the bloodstream from the body's tissues to the liver. Once in the liver, cholesterol and phospholipids are redistributed to other tissues or removed from the body. ApoA-I attaches to cell membranes and promotes the movement of cholesterol and phospholipids from inside the cell to the outer surface. Once outside the cell, these substances combine with apoA-I to form HDL. ApoA-I also triggers a reaction called cholesterol esterification that converts cholesterol to a form that can be fully integrated into HDL and transported through the bloodstream. HDL is often referred to as "good cholesterol" because high levels of this substance reduce the chances of developing heart and blood vessel (cardiovascular) disease. The process of removing excess cholesterol from cells is extremely important for balancing cholesterol levels and maintaining cardiovascular health.
Conditions with Increased Gene Activity
| Condition | Change (log2fold) | Comparison | Species | Experimental variables | Experiment name |
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Conditions with Decreased Gene Activity
| Condition | Change (log2fold) | Comparison | Species | Experimental variables | Experiment name |
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Technical
The following transcription factors affect gene expression:
Tissue specificity:
Major protein of plasma HDL, also found in chylomicrons. Synthesized in the liver and small intestine. The oxidized form at Met-110 and Met-136 is increased in individuals with increased risk for coronary artery disease, such as in carrier of the eNOSa/b genotype and exposure to cigarette smoking. It is also present in increased levels in aortic lesions relative to native ApoA-I and increased levels are seen with increasing severity of disease.
Gene Pathways:
Molecular Function:
- Beta-Amyloid Binding
- Phospholipid Binding
- Phospholipid Transporter Activity
- High-Density Lipoprotein Particle Binding
- Cholesterol Binding
- Cholesterol Transporter Activity
- Enzyme Binding
- Phosphatidylcholine Binding
- Apolipoprotein Receptor Binding
- Apolipoprotein A-I Receptor Binding
- Identical Protein Binding
- Chemorepellent Activity
- Lipase Inhibitor Activity
- Phosphatidylcholine-Sterol O-Acyltransferase Activator Activity
- High-Density Lipoprotein Particle Receptor Binding
Biological Processes:
- Retinoid Metabolic Process
- Regulation Of Protein Phosphorylation
- Endothelial Cell Proliferation
- Platelet Degranulation
- Negative Regulation Of Cytokine Secretion Involved In Immune Response
- Phospholipid Metabolic Process
- Phosphatidylcholine Biosynthetic Process
- Cholesterol Biosynthetic Process
- Receptor-Mediated Endocytosis
- G-Protein Coupled Receptor Signaling Pathway
- Integrin-Mediated Signaling Pathway
- Response To Nutrient
- Cholesterol Metabolic Process
- Glucocorticoid Metabolic Process
- Negative Regulation Of Tumor Necrosis Factor-Mediated Signaling Pathway
- Positive Regulation Of Cholesterol Esterification
- Positive Regulation Of Triglyceride Catabolic Process
- Negative Regulation Of Very-Low-Density Lipoprotein Particle Remodeling
- Peripheral Nervous System Axon Regeneration
- Protein Oxidation
- Peptidyl-Methionine Modification
- Triglyceride Catabolic Process
- Lipid Storage
- Regulation Of Intestinal Cholesterol Absorption
- Cholesterol Transport
- Adrenal Gland Development
- Animal Organ Regeneration
- Neuron Projection Regeneration
- Regulation Of Cdc42 Protein Signal Transduction
- Cholesterol Efflux
- Phospholipid Efflux
- Negative Regulation Of Heterotypic Cell-Cell Adhesion
- High-Density Lipoprotein Particle Remodeling
- High-Density Lipoprotein Particle Assembly
- High-Density Lipoprotein Particle Clearance
- Positive Regulation Of Rho Protein Signal Transduction
- Lipoprotein Metabolic Process
- Lipoprotein Biosynthetic Process
- Cholesterol Homeostasis
- Blood Vessel Endothelial Cell Migration
- Response To Estrogen
- Reverse Cholesterol Transport
- Cellular Protein Metabolic Process
- Positive Regulation Of Fatty Acid Biosynthetic Process
- Negative Regulation Of Interleukin-1 Beta Secretion
- Negative Regulation Of Inflammatory Response
- Protein Stabilization
- Negative Chemotaxis
- Positive Regulation Of Lipoprotein Lipase Activity
- Vitamin Transport
- Positive Regulation Of Hydrolase Activity
- Positive Regulation Of Stress Fiber Assembly
- Transmembrane Transport
- Phospholipid Homeostasis
- Negative Regulation Of Lipase Activity
- Negative Regulation Of Cell Adhesion Molecule Production
- Negative Regulation Of Response To Cytokine Stimulus
- Triglyceride Homeostasis
- Cholesterol Import
- Positive Regulation Of Substrate Adhesion-Dependent Cell Spreading