Stannin is a protein that has been localized to trimethyltin-sensitive
cell populations, and evidence suggests it plays a role in the toxic
effects of organotins. In this study, we have isolated a mouse stannin
genomic clone and have characterized the gene's intron-exon organizat
ion, promoter region, and chromosomal location. We have also isolated
a partial human stannin cDNA clone and analyzed the open reading frame
. The mouse genomic clone spans similar to 19 kb and consists of one i
ntron and two exons. The splice site consensus sequence was maintained
at all intron-exon junctions. Promoter analysis suggests that two put
ative promoter sites exist, each containing multiple regulatory elemen
ts and transcription factor-binding sites. Fluorescence in situ hybrid
ization analysis localized stannin to mouse Chromosome (Chr) 16 at ban
d A2. This region is homologous to the proximal region of human Chr 16
(16p13) to which stannin has been previously mapped. Sequence analysi
s revealed that the 264-bp open reading frame was identical between ra
t and mouse. The human sequence was 98% identical, with two amino acid
substitutions near the c-terminal end of the peptide. These data sugg
est that stannin is highly conserved between species, and its unusual
pattern of cellular expression may, in part, be explained via cell-spe
cific promoters.