The function of LRP1 (LDL receptor related protein 1, Ensembl gene identifier ENSG00000123384) is as follows. Endocytic receptor involved in endocytosis and in phagocytosis of apoptotic cells (PubMed:11907044, PubMed:12713657). Required for early embryonic development (By similarity). Involved in cellular lipid homeostasis. Involved in the plasma clearance of chylomicron remnants and activated LRPAP1 (alpha 2-macroglobulin), as well as the local metabolism of complexes between plasminogen activators and their endogenous inhibitors. Acts as an LRPAP1 alpha-2- macroglobulin receptor (PubMed:1702392, PubMed:26142438). Acts as TAU/MAPT receptor and controls the endocytosis of TAU/MAPT as well as its subsequent spread (PubMed:32296178). May modulate cellular events, such as APP metabolism, kinase-dependent intracellular signaling, neuronal calcium signaling as well as neurotransmission (PubMed:12888553). Also acts as a receptor for IGFBP3 to mediate cell growth inhibition (PubMed:9252371). {ECO:0000250|UniProtKB:Q91ZX7, ECO:0000269|PubMed:11907044, ECO:0000269|PubMed:12713657, ECO:0000269|PubMed:12888553, ECO:0000269|PubMed:1702392, ECO:0000269|PubMed:26142438, ECO:0000269|PubMed:32296178, ECO:0000269|PubMed:9252371}. (Microbial infection) Functions as a receptor for Pseudomonas aeruginosa exotoxin A. . (Microbial infection) Functions as a receptor for yellow fever virus. .