FIGURE 3.
RBM15B interacts with N-terminal extension of CDK11p110, cyclin L2α, and 9G8. A, [35S]methionine-labeled CDK11p110 IVTT products were generated from translation initiating at several internal AUG codons indicated as their corresponding methionines (1–9). Methionine (Met) 1 corresponds to the translation start for full-length CDK11p110, whereas Met-9 is the translation start for the CDK11p58 isoform. The polyglutamine (poly E) domain of CDK11p110 is located between methionines 8 and 9. The GST pulldown assay was performed using CDK11p110 IVTT products incubated with GST-RBM15B FL and GST as control. B, pulldown assay using the GST-RBM15B N-term (Δ9) and C-term RBM15B (Δ15) fusion proteins incubated with [35S]methionine-labeled IVTT products of CDK11p110, the N-term domain of CDK11p110 upstream of the sequence of CDK11p58, CDK11p58, cyclin L2α, and bacterially produced recombinant 9G8 protein. IVTT products were visualized by autoradiography, whereas 9G8 was detected by immunoblotting.