CELLULAR PATHWAY OF THE LDL RECEPTOR

LDL receptor is synthesized as a precursor with the apparent molecular weight of 120kDa.
 N- and O-linked sugars are added to the LDL receptor precursor in the endoplasmic reticulum and in Golgi resulting in an increase of the apparent weight of the LDL receptor up to 160 kDa.

 LDL receptor is localized on the outer cellular membrane mostly in the coated pits. LDL particles  bound to the receptor are internalized into coated vesicles. These vesicles are uncoated in the cell, their media is acidified and they transform into endosomes. The dissociation of the receptor and ligand occurs in the endosomes.

 The free receptor is returns in the recycling vesicles onto the plasmatic membrane. The LDL protein and lipids are degraded in the lysosomes. The free cholesterol from LDL particles has several regulatory effects on cellular metabolism. The most important  of these regulatory effects are the lowering of the intracellular cholesterol production, suppression of the LDL receptor gene transcription and increase in formation of intracellular cholesteryl esters.

The material for this page is provided by F.M.Zakharova

Domain structure of the LDL receptor

LDL receptor structure and function