DAZAP1 interacts via its RNA-recognition motifs with the C-termini of other RNA-binding proteins

The turnover and translation of many human mRNAs is regulated by AU-rich elements present in their 3′untranslated region, which bind various trans acting factors. We previously identified a trans acting factor that interacts with these cis elements as DAZAP1 (deleted in Azoospermia (DAZ)-Associated Protein 1), whose interaction with the germ cell-specific protein DAZ was disrupted by the phosphorylation of DAZAP1. Here we have identified several other RNA-binding proteins as binding partners for DAZAP1 in non-germinal cells. Unlike DAZ, these interactions occur between the RNA recognition motifs of DAZAP1 and the C-termini of the binding partners and in a phosphorylation-independent manner. The results suggest that DAZAP1 is a component of complexes that are crucial for the degradation and silencing of mRNA.