The LDL receptor-related protein (LRP) is a multifunctional scavenger and signaling receptor with diverse biological roles. Structurally, LRP consists of five common units: ligand-binding repeats, EGF-like repeats, YWTD domains, a single membrane-spanning segment, and a cytoplasmic tail containing NPxY motifs. These features enable LRP to bind a wide range of ligands, including proteinases, proteinase inhibitors, viruses, toxins, and intracellular proteins. LRP interacts with intracellular adapter and scaffold proteins, such as Dab1 and FE65, which mediate various cellular processes. In lipoprotein metabolism, LRP plays a crucial role in the clearance of chylomicron remnants and the regulation of hepatic remnant metabolism. It also regulates extracellular proteolytic activity by modulating serine and metalloproteinases. Additionally, LRP is involved in the activation of lysosomal enzymes and the entry of viruses and toxins into cells. In neurons, LRP may contribute to long-term potentiation and synaptic plasticity. Furthermore, LRP's role in Alzheimer's disease is complex, as it influences both Aβ production and clearance. Overall, LRP's functions extend beyond its role as an endocytic receptor, highlighting its importance in cellular signaling and homeostasis.The LDL receptor-related protein (LRP) is a multifunctional scavenger and signaling receptor with diverse biological roles. Structurally, LRP consists of five common units: ligand-binding repeats, EGF-like repeats, YWTD domains, a single membrane-spanning segment, and a cytoplasmic tail containing NPxY motifs. These features enable LRP to bind a wide range of ligands, including proteinases, proteinase inhibitors, viruses, toxins, and intracellular proteins. LRP interacts with intracellular adapter and scaffold proteins, such as Dab1 and FE65, which mediate various cellular processes. In lipoprotein metabolism, LRP plays a crucial role in the clearance of chylomicron remnants and the regulation of hepatic remnant metabolism. It also regulates extracellular proteolytic activity by modulating serine and metalloproteinases. Additionally, LRP is involved in the activation of lysosomal enzymes and the entry of viruses and toxins into cells. In neurons, LRP may contribute to long-term potentiation and synaptic plasticity. Furthermore, LRP's role in Alzheimer's disease is complex, as it influences both Aβ production and clearance. Overall, LRP's functions extend beyond its role as an endocytic receptor, highlighting its importance in cellular signaling and homeostasis.