Sandbox Reserved 595: Difference between revisions

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=Function=

==Lipid Metabolism==

The protein, apolipoprotein E, has an important role in lipid metabolism; principally, it serves as a carrier protein. ApoE combines with lipids in the body to form lipoprotein particles (X,Z). These lipoprotein particles have hydrophobic lipids situated at the core and hydrophilic side chains made of amino acids (Z). Specifically, apoE is responsible for packaging cholesterol ~~and~~ other lipids and transporting them systemically (X,AA).

The protein, apolipoprotein E, has an important role in lipid metabolism; principally, it serves as a carrier protein. ApoE combines with lipids in the body to form lipoprotein particles (X,Z). These lipoprotein particles have hydrophobic lipids situated at the core and hydrophilic side chains made of amino acids (Z). Specifically, apoE is responsible for packaging cholesterol,other lipids, and fat soluble vitamins and transporting them systemically (X,AA).

Synthesis of this protein primarily occurs in the liver; approximately three-fourths of plasma apoE is generated in the liver by hepatic parenchymal cells (X). In this location, apoE is included as a major component of very-low density lipoproteins (VLDL) (X,Z). VLDL serves to remove excess cholesterol from the blood and to carry it to the liver for processing. Thus, apoE acts as a cholesterol chaperone (R). Maintaining optimal levels of cholesterol is crucial for the prevention of disorders that affect the heart and blood levels (X). Triglycerides are also transported to the liver tissue with the aid of VLDL (Z). ApoE is essential for the normal catabalism of triglyceride-rich lipoprotein constituents (R). In the plasma, apoE will associate with most lipoproteins, however, n the central nervous system, it mainly associates with high-density lipoproteins (HDL) (AA).

Another way in which apoE is involved in the metabolsim of lipids is through binding to the low denstiy lipoprotein receptor; apoE assists in both the transportation of lipids and the facilitation of their uptake. ApoE mediates the receptor binding of apoE lipoprotein particles to the LDL recptor, an action that initiates the cellular uptake of lipoproteins (Z). Following the receptor-mediated endocytosis of apoE-containing lipoprotein particles by LDL receptor family member, apoE may undero one of two fates. ApoE can either be degraded, or it can be recycled back to the cell surface (AA). One other function that apoE plays with regards to lipid metabolism takes place within the intestinal tract. ApoE has the ability to incorporate into intestinally synthesized chylomicrons. By doing so, apoE can transport dietary triglycerides and cholesterol (Z).

==Neurological==

In the brain, apoE is primarily produced by astrocytes. ApoE in the brain is thought to deliver cholesterol and other lipids to neurons through the process of receptor-mediated endocytosis (R). It may also play in important role in synaptic integrity and plasticity (R). For, cholesterol released from apoE-containing lipoprotein particles is used to support synaptogenesis as well as the maintenance of synaptic connections (AA).

==Immunological==

ApoE can bind lipid antigens. Once binding occurs, apoE delivers the antigens, via receptor-mediated uptake, into endosomal compartments containing CD1 in antigen-processing cells. This protein can be secreted by antigen-presenting cells for the purpose of surveying the local environment and transfer microbial lipids from infected cells to bystander antigen-presenting cells. In one study, apoE mediated the presentation of serum-bovine lipid antigens. In this way, the immune system has co-opted a component of lipid metabolism in order to raise immunologic responses to lipid antigens (W).

Sandbox Reserved 595: Difference between revisions

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@@ Line 29: / Line 29: @@
 =Function=
 ==Lipid Metabolism==
-The protein, apolipoprotein E, has an important role in lipid metabolism; principally, it serves as a carrier protein.  ApoE combines with lipids in the body to form lipoprotein particles (X,Z).  These lipoprotein particles have hydrophobic lipids situated at the core and hydrophilic side chains made of amino acids (Z).  Specifically, apoE is responsible for packaging cholesterol and other lipids and transporting them systemically (X,AA).
+The protein, apolipoprotein E, has an important role in lipid metabolism; principally, it serves as a carrier protein.  ApoE combines with lipids in the body to form lipoprotein particles (X,Z).  These lipoprotein particles have hydrophobic lipids situated at the core and hydrophilic side chains made of amino acids (Z).  Specifically, apoE is responsible for packaging cholesterol,other lipids, and fat soluble vitamins and transporting them systemically (X,AA).
+Synthesis of this protein primarily occurs in the liver; approximately three-fourths of plasma apoE is generated in the liver by hepatic parenchymal cells (X).  In this location, apoE is included as a major component of very-low density lipoproteins (VLDL) (X,Z).  VLDL serves to remove excess cholesterol from the blood and to carry it to the liver for processing.  Thus, apoE acts as a cholesterol chaperone (R).  Maintaining optimal levels of cholesterol is crucial for the prevention of disorders that affect the heart and blood levels (X).  Triglycerides are also transported to the liver tissue with the aid of VLDL (Z).  ApoE is essential for the normal catabalism of triglyceride-rich lipoprotein constituents (R).  In the plasma, apoE will associate with most lipoproteins, however, n the central nervous system, it mainly associates with high-density lipoproteins (HDL) (AA).
+Another way in which apoE is involved in the metabolsim of lipids is through binding to the low denstiy lipoprotein receptor; apoE assists in both the transportation of lipids and the facilitation of their uptake.  ApoE mediates the receptor binding of apoE lipoprotein particles to the LDL recptor, an action that initiates the cellular uptake of lipoproteins (Z).  Following the receptor-mediated endocytosis of apoE-containing lipoprotein particles by LDL receptor family member, apoE may undero one of two fates.  ApoE can either be degraded, or it can be recycled back to the cell surface (AA).  One other function that apoE plays with regards to lipid metabolism takes place within the intestinal tract.  ApoE has the ability to incorporate into intestinally synthesized chylomicrons.  By doing so, apoE can transport dietary triglycerides and cholesterol (Z).
+==Neurological==
+In the brain, apoE is primarily produced by astrocytes.  ApoE in the brain is thought to deliver cholesterol and other lipids to neurons through the process of receptor-mediated endocytosis (R).  It may also play in important role in synaptic integrity and plasticity (R).  For, cholesterol released from apoE-containing lipoprotein particles is used to support synaptogenesis as well as the maintenance of synaptic connections (AA).
 ==Immunological==
 ApoE can bind lipid antigens.  Once binding occurs, apoE delivers the antigens, via receptor-mediated uptake, into endosomal compartments containing CD1 in antigen-processing cells.  This protein can be secreted by antigen-presenting cells for the purpose of surveying the local environment and transfer microbial lipids from infected cells to bystander antigen-presenting cells.  In one study, apoE mediated the presentation of serum-bovine lipid antigens.  In this way, the immune system has co-opted a component of lipid metabolism in order to raise immunologic responses to lipid antigens (W).