GSE36987
PAPD5, a noncanonical poly(A) polymerase with an unusual RNA-binding motif [PAR-CLIP]
PAPD5 is one of the seven members of non-canonical poly(A) polymerases in human cells. There are previous reports about polyadenylation dependent degradation of pre-ribosomal RNAs and uridylation dependent degradation of histone mRNAs in vivo. In this study, we observed polyadenylation but not polyuridylation activity of PAPD5 with in vitro assays. We aimed to get genome-wide targets of PAPD5 and used PAR-CLIP and deep sequencing for this purpose. Overall design: Recombinant version of PAPD5 is expressed in HEK293 human cell lines and its genome wide targets are obtained with PAR-CLIP and deep sequencing as two replicate experiments. The short reads in the deep sequencing libraries of PAPD5 replicates and an unrelated protein to polymerization from a previous study, IGF2BP1, are aligned to the hg18 human genome assembly. The biological variance of the read counts in overlapping 100-nucleotide-long-windows is estimated between the PAPD5 replicates and further used in the differential expression estimations between the 100-nucleotide windows in PAPD5 replicates and IGF2BP1. The top differentially expressed windows in PAPD5 and IGF2BP1 are further annotated using gene and repeat tracks from UCSC.