FIGURE 5.

Phosphomimetic Y383E mutation or phosphorylation of YY1 at tyrosine 383 impairs its ability to bind DNA and RNA. A, SDS-PAGE and Coomassie Blue staining of affinity purified His₆-tagged recombinant YY1 produced in Escherichia coli. B, EMSA were performed using biotin-labeled MLV-NCR or AAV-P5 oligonucleotides and bacterially purified His₆-tagged YY1. Formation of the YY1-DNA complex is indicated by the arrow. Data shown are representative of three independent experiments. C, in vitro phosphorylated YY1 (left panel) was used for EMSA using biotin-labeled MLV-NCR probe (right panel). Formation of the YY1-DNA complex is indicated by the arrow. Data shown are representative of two independent experiments. WB, Western blot. D, bacterially purified His₆-tagged YY1 was subjected to an in vitro RNA binding assay using biotin-labeled HTLV-1 R RNA or control RNA. Formation of the YY1-RNA complex was monitored by Western blotting with anti-His₆ antibody.