Figure 1.

Identification of UCA1 as an hnRNP I-binding partner. (a) Enrichment of UCA1 by hnRNP I antibody, as detected by RIP assay. (b) Confirmation of the interaction between UCA1 and hnRNP I by RNA precipitation assay using UCA1 RNA probe. Preparation of UCA1 RNA probe and cellular extract from MCF-7 cells were detailed in the text. (c) The 5′ end of UCA1 is responsible for its interaction with hnRNP I, as detected by RNA precipitation. UCA1 RNA probes used in this experiment were indicated in top panel. RoR exon 4 was used as a positive control. (d) A putative hnRNP I-binding motif in UCA1 is critical to its interaction with hnRNP I. Description of the mutant UCA1 at the putative hnRNP I-binding site was indicated in left panel where the conserved binding motif was underlined. Y, either C or T. Detection of hnRNP I in the pellets by western blot as indicated in right panel. Error bars represent S.E.M., n=3. **P<0.01