FIG. 7.

Model of the α-complex function during α-globin mRNA deadenylation. The α-globin mRNA is denoted by a line, the filled circle represents the 5′ cap, and the translation start (AUG) and stop (UAA) sites with the traversing ribosomes shown within the coding region. The α-complex indicated by the large oval on the 3′UTR includes the four unknown proteins p58, p55, p50, and p28 along with AUF1 and an αCP (28). The poly(A) tail is shown on the 3′ end bound by two PABPs. A potential interaction between the αCP in the α-complex and PABP on the poly(A) tail is shown. A putative deadenylase is indicated. The interaction between the α-complex and PABP is postulated to stabilize the poly(A) tail by rendering it resistant to deadenylation.