Mammalian long intergenic noncoding RNAs (lincRNAs) are best known for 
modulating transcription. Here we report a posttranscriptional function for 
lincRNA-p21 as a modulator of translation. Association of the RNA-binding 
protein HuR with lincRNA-p21 favored the recruitment of let-7/Ago2 to 
lincRNA-p21, leading to lower lincRNA-p21 stability. Under reduced HuR levels, 
lincRNA-p21 accumulated in human cervical carcinoma HeLa cells, increasing its 
association with JUNB and CTNNB1 mRNAs and selectively lowering their 
translation. With elevated HuR, lincRNA-p21 levels declined, which in turn 
derepressed JunB and β-catenin translation and increased the levels of these 
proteins. We propose that HuR controls translation of a subset of target mRNAs 
by influencing lincRNA-p21 levels. Our findings uncover a role for lincRNA as a 
posttranscriptional inhibitor of translation.