Molecular cloning of mouse Lrp7(Lr3) cDNA and chromosomal mapping of orthologous genes in mouse and human

LRP7 (the HGMW-approved gene symbol for LR3) is a novel member of the low-density lipoprotein receptor (LDLR) family. The unique modular features in both its extracellular and its intracellular regions and functional analysis suggest it to be a multifunctional protein with mitogenic activity and potential ligand-induced signal transduction capability. We describe here the cloning of Lrp7, the orthologue of the human LRP7 gene, from a mouse liver cDNA library and its expression profile in mouse tissues and developmental stages. Lrp7 is highly homologous to the human sequence, with 95% identity at the amino acid level and a perfect conservation of all the recognizable functional domains. A 6-kb mRNA transcript could be detected in all the tissues examined, with the highest expression levels in Liver, heart, and lung and the low est levels in brain and spleen. A similar expression level of a smaller transcript (4.5 kb) was seen at the four embryonic stages examined. We mapped the Lrp7 gene to mouse chromosome 19B and the LRP7 gene to human chromosome 11q13.4. The LRP7 gene was also localized by radiation hybrid mapping between markers D11S24270 and D11S1975. (C) 1999 Academic Press.