Heterogeneous nuclear ribonucleoprotein D/AUF1 interacts with heterogeneous nuclear ribonucleoprotein L

Heterogeneous nuclear ribonucleoprotein L (hnRNP L) is one of the principal pre-mRNA-binding proteins found in human cells. The hnRNP L protein is fairly abundant. However, it is not restricted to the nucleus, and instead shuttles between the nucleus and the cytoplasm. It is composed of 558 amino acid residues and harbours four loosely conserved RNP-consensus RNA-binding domains. In an attempt to characterize the interaction occurring between cellular proteins and hnRNP L, yeast two-hybrid screening was conducted using a HeLa cDNA library. Some of the cDNA clones were found to harbour a partial human hnRNP D/AUF1 cDNA (GeneBank accession number NM_031369). In this study, we determined that hnRNP L interacts specifically with the hnRNP D/AUF1 in the yeast two-hybrid system. This interaction was verified via an in vitro pull-down assay.