Fig. 4
From: Roles of piRNAs in transposon and pseudogene regulation of germline mRNAs and lncRNAs
The piRNA-Piwi complex mediates transcriptional activation of target mRNAs. a In Drosophila germ plasm, Aub interacts with PABP and eIF3 subunits to allow unconventional translation and recruits Wispy poly(A) polymerase to facilitates polyadenylation which also promotes translation [94]. This process is dependent on Cup binding to eIF4E. b In mouse spermatids, the piRNA-PIWIL1 complex binds to eIF3f and the 3′ UTRs of ARE-containing target mRNAs, which triggers mRNA looping [95]. HuR binds to the ARE sequences and mediates the association of other translation initiation factors, including eIF4G and PABPC1, to activate translation