Isolation and molecular characterization of rasfadin, a novel gene in the vicinity of the bovine prion gene

A novel gene, rasfadin (RASSF2) was identified close to the bovine prion ge ne, and its genomic structure was derived with a combination of exon trappi ng and RACE. The gene covers at least 28 kb and maps to the same chromosoma l region as the prion gene in cattle, sheep, and human. The RASSF2 ORF is c omposed of 987 base pairs divided into nine exons and shows a high nucleoti de (88%) and amino acid similarity (95%) with a previously described human cDNA, KIAA0168. The bovine 3'UTR region is significantly shorter than the h uman counterpart, but shares with it two highly conserved nucleotide blocks . The expression of the gene was investigated in brain, liver, and spleen. Alternative splicing yields a shorter product in the liver composed of only four exons. Computer analysis showed a highly significant similarity of th e rasfadin protein with the Ras association (Ra1-GDS/AF-6) domain family 2 and with the afadin family, respectively, for the longer brain/spleen and t he shorter liver variants.