What is "polyuridylation"

Polyuridylation, also called oligouridylation, is the addition of several uridine nucleotides to the 3' end of an RNA. One group of RNAs that can be polyuridylated are histone mRNAs that lack a poly(A) tail. Polyuridylation of a histone mRNA promotes its degradation, involving the exosome. Other RNAs in Arabidopsis and mouse have been seen to be polyuridinylated after cleavage.