Fig. 4. CLIP of Thor-V5 identifies a direct RNA binding activity.

(A) Schematic illustration of CLIP. UV–cross-linked and lysed Thor-V5 cells were treated with RNase A, and then immunoprecipitation was carried out from cell lysate using an antibody against V5 tag. The partially digested RNAs, which had been cross-linked to RBP, were labeled at their 5′ end by [γ-³²P]ATP. Radioisotope-labeled RNA-RBP could be separated and visualized in denaturing LDS polyacrylamide gel. LDS, lithium dodecyl sulfate. (B) CLIP of Thor-V5 shows that Thor has an RNA binding activity. A well-known RBP, Hrp48, was used as a positive control. S2 or Thor-V5 cells were UV–cross-linked (UV⁺) or not (UV⁻). Immunoprecipitation was carried out using antibody against V5 tag or Hrp48.