A complex polymorphism, a 6-nucleotide insertion/deletion in the 3′-untranslated region of the thymidylate synthase (TS) gene, affects mRNA stability by modulating the binding of AUF1 to TS mRNA. Pullmann and colleagues demonstrated that AUF1 has higher affinity for the deletion in the 3′UTR TS mRNA, consequently rendering it less stable, compared to the insertion in the same site. Additionally, they demonstrated that AUF1 overexpression preferentially suppressed the deletion allele.76
