Figure 6.

E3 and E2 titration.A, titration of Nedd8–CRL4^CRBN. B, comparison of Cdc34b and UBE2G1 in the ubiquitination of CK1α. The reaction was carried out as described for Figure 1. C, comparison of Cdc34b and UBE2G1 in the “apyrase chase” reaction. Priming reaction with UbcH5c was 30 s at 37 °C. The elongation with Cdc34b was 3 min at 37 °C. Graphs integrate data in triplets with indicated error bars. CK1α, casein kinase 1α; CRBN, cereblon; CRL, Cullin–RING E3 Ub ligase; Nedd8, neural precursor cell expressed, developmentally downregulated 8.