Cloning of the human homolog of conductin (AXIN2), a gene mapping to chromosome 17q23-q24

Conductin or Axil, an Axin homolog, plays an important role in the regulati on of beta-catenin stability in the Wnt signaling pathway. To facilitate th e molecular analysis of the human gene, we isolated the human homolog, AXIN 2. The cDNA contains a 2529-bp open reading frame and encodes a putative pr otein of 843 amino acids. Compared with rat and mouse homologs, AXIN2 shows an overall 89% amino acid identity. Several functional domains in this pro tein are highly conserved including the GRS (95.9%), GSK-3 beta (96.3%), Ds h (98%), and beta-catenin (89.9%) domains. Radiation hybrid mapping localiz ed the AXIN2 gene to human chromosome 17q23-q24, a region that shows freque nt loss of heterozygosity in breast cancer, neuroblastoma, and other tumors . Human AXIN2 is thus a very strong candidate involved in multiple tumor ty pes. (C) 1999 Academic Press.