hnRNP D (AUF1)
AUF1, or hnRNP D (heterogeneous nuclear ribonucleoprotein D), was one of the first trans-acting factors identified that binds AU-rich elements (AREs) within the 3′ UTR (UTR – untranslated region) of many labile mRNAs (Brewer 1991). The importance of AREs in promoting rapid RNA turnover has been well characterized (Guhaniyogi and Brewer 2001). A mechanism was still under investigation when AUF1 was discovered. AUF1 as an ARE-binding protein (AUBP) was first identified in specific fractions of cytosol separated by sucrose gradient fractionation (Brewer 1991). Electrophoretic mobility shift assays (EMSAs) of these fractions revealed 37 and 40 kDa (kD) polypeptides that specifically bound ARE-containing c- myc mRNA. Cell-free decay assays confirmed c-mycmRNA degradation occurred within the same fractions that included the ARE-binding activity. The aforementioned polypeptides, now referred to as p37...
- Liao B, Hu Y, Brewer G. Competitive binding of AUF1 and TIAR to MYC mRNA controls its translation. Genes Dev. 2007;20:3174–84.Google Scholar