Demonstration in vitro that recombinant hnRNP-K binds the +18/+39 region of the CD43 promoter.

A radiolabeled single-stranded oligonucleotide, CD43 PyRo SS56, representing nucleotides +18 to +39 of the sense strand of the CD43 gene was incubated with no protein (Probe), purified GST (GST), or purified GST/hnRNP-K fusion protein (GST-K). Binding reactions containing GST/hnRNP-K were performed in the absence (GST-K) or presence (+) of a 100-fold molar excess of unlabeled CD43 PyRo SS, the presence of Mut-11 (Mut) representing a mutant version of CD43 PyRo SS, which fails to support PyRo1 binding56 or the presence of the unrelated oligonucleotide NS-SS (NS). The free probe and probe bound by the GST/hnRNP-K protein (GST:hnRNP-K) are denoted by arrows.