Figure 2.

Southwestern blot analysis and UV cross-linking assay demonstrate RIIβ binding to CRE oligonucleotide. (A) Southwestern blot analysis. Lanes: 2 and 4, DT and DTRIIβ cell nuclear extracts; 3 and 5, immunoprecipitated RIIβ from DT and DTRIIβ nuclear extracts; 1, immunoprecipitated CREB from DT nuclear extract; M, ¹⁴C-labeled marker proteins. (B) UV cross-linking assay of DT and DTRIIβ cell nuclear extracts. Lanes: 2 and 4, DT and DTRIIβ cell nuclear extracts; 3 and 5, immunoprecipitated RIIβ from DT and DTRIIβ nuclear extracts; 1, immunoprecipitated CREB from DTRIIβ nuclear-extract; RIα, photoaffinity-labeled 48-kDa RI; RIIα, photoaffinity-labeled 56-kDa RII (Sigma). (C) UV cross-linking assay of DTRIIβ and DTRIIβ-P cell nuclear extracts. Lanes: 1 and 2, DTRIIβ-P and DTRIIβ nuclear extracts; 3 and 4, immunoprecipitated RIIβ from DTRIIβ-P and DTRIIβ nuclear extracts. The data represent one of three to five experiments that gave similar results.