Ectodomains of the LDL Receptor-Related Proteins LRP1b and LRP4 Have Anchorage Independent Functions In Vivo

The low-density lipoprotein (LDL) receptor gene family is a highly conserved group of membrane receptors with diverse functions in developmental processes, lipoprotein trafficking, and cell signaling. The low-density lipoprotein (LDL) receptor-related protein 1b (LRP1B) was reported to be deleted in several types of human malignancies, including non-small cell lung cancer. Our group has previously reported that a distal extracellular truncation of murine Lrp1b that is predicted to secrete the entire intact extracellular domain (ECD) is fully viable with no apparent phenotype.