“…Leishmania harbors a large family of extinct retroposons, SIDERs (Short Interspersed DEgenerated Retroposons), that are widely distributed within the 3′ UTRs of unrelated transcripts and participate in posttranscriptional regulation (Bringaud et al, 2007;Smith et al, 2009;Muller et al, 2010). Uridine-rich elements (UREs), initially reported as destabilization factors in protooncogenes and cytokine mRNAs in mammalian cells (Chen and Shyu, 1995;Schoenberg and Maquat, 2012), and URE-binding proteins have been described in T. brucei (Hotz et al, 1997;Quijada et al, 2002;Mayho et al, 2006) and T. cruzi (Di Noia et al, 2000;Rodrigues et al, 2010;Li et al, 2012) and more recently in Leishmania (Haile et al, 2008). Other non-categorized elements within 3′ UTRs involved in stage-specific mRNA regulation, such as the PRE element AUGUAnAGUn are responsible for the degradation of transcripts encoding paraflagellar rod subunits or an antigenic protein in L. mexicana (Mishra et al, 2003;Holzer et al, 2008).…”