GPIHBP1

GPIHBP1 (GlycosylPhosphatidylInositol Anchored High Density Lipoprotein Binding Protein 1) is a protein that in humans is encoded by the GPIHBP1 gene. It is a member of the Ly6/uPAR family and plays a critical role in the lipolytic processing of chylomicrons.

Function

GPIHBP1 is an endothelial cell protein that binds lipoprotein lipase (LPL) and chylomicrons. This binding is essential for the lipolytic processing of chylomicrons in capillaries. Defects in the GPIHBP1 gene are the cause of chylomicronemia, also known as hyperlipoproteinemia type 1B.

Clinical significance

Mutations in GPIHBP1 cause severe forms of hypertriglyceridemia. Patients with GPIHBP1 mutations have low plasma levels of LPL and apolipoprotein C-II, despite having normal amounts of these proteins in their tissues. This suggests that GPIHBP1 is necessary for the proper plasma distribution of these proteins.

Structure

The GPIHBP1 protein has a three-fingered structure, similar to other members of the Ly6/uPAR family. It is anchored to the cell surface by a glycosylphosphatidylinositol (GPI) anchor.

See also

• Lipoprotein lipase
• Chylomicron
• Hypertriglyceridemia

External links

• GeneCards - GPIHBP1