Smad4^E6sad

Sequence analysis identified a deletion of a single A in the exon 6 splice acceptor site. The resultant activation of a cryptic splice site 4 nt downstream of exon 6 lead to a frameshift mutation at amino acid 261 which in turn created a nonsense mutation 71 codons downstream. RT-PCR analysis indicated decreased transcript stability, putatively due to nonsense mediated decay. Protein was undetected by Western blot analysis of homozygous mutant ES cells. (J:81488)