Lipoprotein receptor-related protein 1 LRP

Peltan, I. D., Thomas, A. V., Mikhailenko, I., Strickland, D. K., Hyman, B. T. and von Arnim, C. A. (2006). Fluorescence lifetime imaging microscopy (FLIM) detects stimulus-dependent phosphorylation of the low density lipoprotein receptor-related protein (LRP) in primary neurons. Biochem. Biophys. Res. Commun. 349, 24-30. 

Lleo, A., Waldron, E., von Amin, C.A.F., et al. (2005) Low density lipoprotein receptor-related protein (LRP) interacts with presenilin 1 and is a competitive substrate of the amyloid precursor protein (APP) for y-secretase. J. Biol. Chem., 280, 27303-27309. 

The rationale for this type of contrast agent is to use the endogenous metabolic pathway of lipid metabolism in the liver for the transport of iodinated substances. Chylomicron remnants are naturally occurring lipoproteins in the blood that are responsible for the transport of lipids into the liver. Three different mechanisms for this transport are discussed direct uptake by the low-density lipoprotein receptor transport to the low-density lipoprotein receptor-related protein (LRP) mediated by heparan sulfate proteoglycan (HSPG) or direct HSPG-LRP uptake and direct HSPG uptake. One of the prerequisites for particles to be transported by these mechanisms is a mean diameter of less than 100-300 run. 

The LDL receptor also binds to apoE and plays a significant role in the hepatic uptake of chylomicrons and VLDL remnants. However, if LDL receptors are unavailable (as, for example, in a mouse strain that lacks the gene for the LDL receptor), VLDL remnants and chylomicrons are still taken up by the liver even though LDL is not. This indicates the presence of a back-up system for receptor-mediated endocytosis of VLDL remnants and chylomicrons. One back-up receptor is lipoprotein receptor-related protein (LRP), which binds to apoE as well as to a number of other ligands. 

Another genomic screen of families with LOAD (62) revealed AD susceptibility locus on chromosome 12 also not linked to the presence of ApoE s4 allele. The o 2-macroglobulin and lipoprotein receptor related protein (LRP) genes present on this chromosome were initially considered as suspects (63). 

Other Activities. IFNy causes a concentration-dependent decrease in steady-state lipoprotein receptor-related protein (LRP) mRNA expression and gene transcription rate. When TGFpl is added 24 hours before IFNy, the extent of LRP down regulation is reduced. This suggests... 

Bu G, Maksymovitch EA, Nerbonne JM, Schwartz AL. Expression and function of the low density lipoprotein receptor-related protein (LRP) in mammalian central neurons. / Biol Chem. 1994 269(28) 18521-18528. 

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