Sterol O-acyltransferase (acyl-Coenzyme A: cholesterol acyltransferase) 1, also known as SOAT1, is an enzyme that in humans is encoded by the SOAT1 gene. [5]
Acyl-coenzyme A:cholesterol acyltransferase (EC 2.3.1.26) is an intracellular protein located in the endoplasmic reticulum that forms cholesterol esters from cholesterol. Accumulation of cholesterol esters as cytoplasmic lipid droplets within macrophages and smooth muscle cells is a characteristic feature of the early stages of atherosclerotic plaques (Cadigan et al., 1988). [5]
SOAT1 is a polytopic integral membrane protein belonging to the membrane-bound O-acyltransferase (MBOAT) superfamily. The structure of SOAT1 has not yet been solved but that of DltB, a bacterial MBOAT, suggests a complex arrangement of multiple transmembrane domains (TMDs). [6] Primary sequences of predicted SOAT1 TMDs indicate many unusual TMD features such as the presence of multiple charged residues within the lipid bilayer. [7] These features can render challenging the integration of a TMD into the hydrophobic phase of the membrane and might therefore require specialised chaperones. A first hint of such a chaperone assisting SOAT1 biogenesis has been the recognition of the involvement of the ER membrane protein complex (EMC), a molecular chaperone and insertase for integral membrane proteins, in maintaining SOAT1 stability. [8]
Click on genes, proteins and metabolites below to link to respective articles. [§ 1]
HMG-CoA reductase is the rate-controlling enzyme of the mevalonate pathway, the metabolic pathway that produces cholesterol and other isoprenoids. HMGCR catalyzes the conversion of HMG-CoA to mevalonic acid, a necessary step in the biosynthesis of cholesterol. Normally in mammalian cells this enzyme is competitively suppressed so that its effect is controlled. This enzyme is the target of the widely available cholesterol-lowering drugs known collectively as the statins, which help treat dyslipidemia.
Lecithin–cholesterol acyltransferase is an enzyme, in many animals including humans, that converts free cholesterol into cholesteryl ester, which is then sequestered into the core of a lipoprotein particle, eventually making the newly synthesized HDL spherical and forcing the reaction to become unidirectional since the particles are removed from the surface. The enzyme is bound to high-density lipoproteins (HDLs) (alpha-LCAT) and LDLs (beta-LCAT) in the blood plasma. LCAT deficiency can cause impaired vision due to cholesterol corneal opacities, anemia, and kidney damage. It belongs to the family of phospholipid:diacylglycerol acyltransferases.
Mitochondrial trifunctional protein (MTP) is a protein attached to the inner mitochondrial membrane which catalyzes three out of the four steps in beta oxidation. MTP is a hetero-octamer composed of four alpha and four beta subunits:
Carnitine palmitoyltransferase I (CPT1) also known as carnitine acyltransferase I, CPTI, CAT1, CoA:carnitine acyl transferase (CCAT), or palmitoylCoA transferase I, is a mitochondrial enzyme responsible for the formation of acyl carnitines by catalyzing the transfer of the acyl group of a long-chain fatty acyl-CoA from coenzyme A to l-carnitine. The product is often Palmitoylcarnitine, but other fatty acids may also be substrates. It is part of a family of enzymes called carnitine acyltransferases. This "preparation" allows for subsequent movement of the acyl carnitine from the cytosol into the intermembrane space of mitochondria.
Lanosterol synthase is an oxidosqualene cyclase (OSC) enzyme that converts (S)-2,3-oxidosqualene to a protosterol cation and finally to lanosterol. Lanosterol is a key four-ringed intermediate in cholesterol biosynthesis. In humans, lanosterol synthase is encoded by the LSS gene.
Acetyl-CoA acetyltransferase, mitochondrial, also known as acetoacetyl-CoA thiolase, is an enzyme that in humans is encoded by the ACAT1 gene.
Diglyceride acyltransferase, DGAT, catalyzes the formation of triglycerides from diacylglycerol and fatty acyl-CoA]. The reaction catalyzed by DGAT is considered the terminal and only committed step in triglyceride synthesis. The conversion is essential for intestinal absorption and adipose tissue formation.
Caveolin-1 is a protein that in humans is encoded by the CAV1 gene.
Sterol regulatory element-binding transcription factor 1 (SREBF1) also known as sterol regulatory element-binding protein 1 (SREBP-1) is a protein that in humans is encoded by the SREBF1 gene.
ATP citrate synthase is an enzyme that in animals represents an important step in fatty acid biosynthesis. By converting citrate to acetyl-CoA, the enzyme links carbohydrate metabolism, which yields citrate as an intermediate, with fatty acid biosynthesis, which consumes acetyl-CoA. In plants, ATP citrate lyase generates cytosolic acetyl-CoA precursors of thousands of specialized metabolites, including waxes, sterols, and polyketides.
Sterol O-acyltransferase is an intracellular protein located in the endoplasmic reticulum that forms cholesteryl esters from cholesterol.
Insulin induced gene 1, also known as INSIG1, is a protein which in humans is encoded by the INSIG1 gene.
Sterol O-acyltransferase 2, also known as SOAT2, is an enzyme that in humans is encoded by the SOAT2 gene.
2-Acylglycerol O-acyltransferase 2 also known as acyl-CoA:monoacylglycerol acyltransferase 2 (MGAT2) or Diacylglycerol O-acyltransferase candidate 5 (DC5) is an enzyme that in humans is encoded by the MOGAT2 gene.
Human acetyl-coA cholesterol acyltransferase (ACAT1) gene produces a chimeric mRNA through the interchromosomal processing of two discontinuous RNAs transcribed from chromosomes 1 and 7. This chimeric mRNA uses AUG as a translation initiation codon to produce the normal 50-kDa ACAT1 protein but used an alternative translation initiation codon, GGC, to produce the novel enzymatically active 56-kDa isoform.
Acetyl-CoA acetyltransferase, cytosolic, also known as cytosolic acetoacetyl-CoA thiolase, is an enzyme that in humans is encoded by the ACAT2 gene
Monolysocardiolipin acyltransferase is a mitochondrial acyltransferase that facilitates the remodeling of monolysocardiolipin (MLCL) into cardiolipin.
The MBOAT family of membrane proteins is a family of various acyltransferase enzymes. All family members contain multiple transmembrane domains and most carry two conserved residues, a conserved histidine (His) embedded in a hydrophobic stretch of residues and an asparagine (Asn) or histidine within a more hydrophilic region some 30-50 residues upstream.
Monoacylglycerol O-acyltransferase 3 is a protein that in humans is encoded by the MOGAT3 gene.
Acyl-CoA thioesterase 13 is a protein that in humans is encoded by the ACOT13 gene. This gene encodes a member of the thioesterase superfamily. In humans, the protein co-localizes with microtubules and is essential for sustained cell proliferation.