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:
- Apolipoprotein A-I Receptor Binding
- Apolipoprotein Receptor Binding
- Beta-Amyloid Binding
- Chemorepellent Activity
- Cholesterol Binding
- Cholesterol Transporter Activity
- Enzyme Binding
- High-Density Lipoprotein Particle Binding
- High-Density Lipoprotein Particle Receptor Binding
- Identical Protein Binding
- Lipase Inhibitor Activity
- Phosphatidylcholine Binding
- Phosphatidylcholine-Sterol O-Acyltransferase Activator Activity
- Phospholipid Binding
- Phospholipid Transporter Activity
Biological Processes:
- Adrenal Gland Development
- Animal Organ Regeneration
- Blood Vessel Endothelial Cell Migration
- Cellular Protein Metabolic Process
- Cholesterol Biosynthetic Process
- Cholesterol Efflux
- Cholesterol Homeostasis
- Cholesterol Import
- Cholesterol Metabolic Process
- Cholesterol Transport
- Endothelial Cell Proliferation
- Glucocorticoid Metabolic Process
- G-Protein Coupled Receptor Signaling Pathway
- High-Density Lipoprotein Particle Assembly
- High-Density Lipoprotein Particle Clearance
- High-Density Lipoprotein Particle Remodeling
- Integrin-Mediated Signaling Pathway
- Lipid Storage
- Lipoprotein Biosynthetic Process
- Lipoprotein Metabolic Process
- Negative Chemotaxis
- Negative Regulation Of Cell Adhesion Molecule Production
- Negative Regulation Of Cytokine Secretion Involved In Immune Response
- Negative Regulation Of Heterotypic Cell-Cell Adhesion
- Negative Regulation Of Inflammatory Response
- Negative Regulation Of Interleukin-1 Beta Secretion
- Negative Regulation Of Lipase Activity
- Negative Regulation Of Response To Cytokine Stimulus
- Negative Regulation Of Tumor Necrosis Factor-Mediated Signaling Pathway
- Negative Regulation Of Very-Low-Density Lipoprotein Particle Remodeling
- Neuron Projection Regeneration
- Peptidyl-Methionine Modification
- Peripheral Nervous System Axon Regeneration
- Phosphatidylcholine Biosynthetic Process
- Phospholipid Efflux
- Phospholipid Homeostasis
- Platelet Degranulation
- Positive Regulation Of Cholesterol Esterification
- Positive Regulation Of Fatty Acid Biosynthetic Process
- Positive Regulation Of Hydrolase Activity
- Positive Regulation Of Lipoprotein Lipase Activity
- Positive Regulation Of Rho Protein Signal Transduction
- Positive Regulation Of Stress Fiber Assembly
- Positive Regulation Of Substrate Adhesion-Dependent Cell Spreading
- Positive Regulation Of Triglyceride Catabolic Process
- Protein Oxidation
- Protein Stabilization
- Receptor-Mediated Endocytosis
- Regulation Of Cdc42 Protein Signal Transduction
- Regulation Of Intestinal Cholesterol Absorption
- Regulation Of Protein Phosphorylation
- Response To Estrogen
- Response To Nutrient
- Retinoid Metabolic Process
- Reverse Cholesterol Transport
- Transmembrane Transport
- Triglyceride Catabolic Process
- Triglyceride Homeostasis
- Vitamin Transport
- Phospholipid Metabolic Process