The molecular mechanism of translational control via the communication between the microRNA pathway and RNA-binding proteins

Abstract

MicroRNAs (miRNAs) are evolutionarily conserved small noncoding RNAs found in most plants and animals. The miRNA pathway regulates posttranscriptional gene expression through the deadenylation and translation repression of target mRNAs. Recent studies revealed that the early step of translation initiation is the target of "pure" translation repression by the miRNA pathway. Moreover, particularly in animals, the miRNA pathway is required for neuronal development, differentiation, and plasticity. In addition, some functions of miRNAs are regulated by RNA-binding proteins (RBPs) in neuronal cells. This review summarizes new insights about the molecular mechanisms of pure translation repression by miRNA pathway and the communication between the miRNA pathway and RBPs in neuronal local translation.

Keywords: RNA-binding protein; deadenylation; local translation; microRNA; pure translation.

Figure 1.

(A) The mechanism of pure translation repression by miRISC in mammal miRISC loading to the target mRNA releases both eIF4AI and eIF4AII from translation initiation complex without deadenylation. Supporting this model, Fukaya et al. also showed that fly Ago1-RISC induces the dissociation of eIF4A from translation initiation complex. (B) The function of HuD for miRNA pathway. The neuronal RNA-binding protein HuD impedes pure translation repression by miRISC via protecting the interaction of eIF4AI and eIF4AII with translation initiation complex on mRNAs.