Genomic organization of a new candidate tumor suppressor gene, LRP1B

LRP1B is a novel candidate tumor suppressor gene that is inactivated by gen etic and transcript alterations in nearly 50% of non-small-cell lung cancer cell lines. The gene-encoded protein is highly homologous to the gigantic lipoprotein receptor-related protein 1 (LRP1) that belongs to the family of low-density lipoprotein receptors, Using a combination of PCR-based genome walking and long-distance interexon PCR, we have determined the genomic or ganization of LRP1B and built a contiguous array of BAC clones spanning thi s gene. A total of 91 exons, varying in size from 77 bases (exon 87) to 189 9 bases (exon 91), were identified in the more than 500-kb-long gene sequen ce. Comparative analysis of the genomic structures of LRP1B and the homolog ous LRP1 gene revealed a striking similarity in the location and sizes of t heir exons, (C) 2000 Academic Press.