FIGURE 3.

N-terminally blocked NGN lacking lysines is still degraded in a ubiquitin-dependent manner in egg extracts. A, degradation assays in interphase egg extract of [³⁵S]methionine-radiolabeled Ac2NGNKO were performed in the presence of the proteasome inhibitor Mg132 (200 μm), epoxomicin (100 μm) or DMSO alone and analyzed by autoradiography and quantitative phosphorimaging analysis. B, degradation assays in interphase egg extract of [³⁵S]methionine-radiolabeled NGN or Ac2NGNKO were performed in the presence (+ER) or absence (+glucose/hexokinase) of ATP, where ER represents Energy Regeneration mix. C, degradation assays of Ac2NGNKO was performed in the presence of ubiquitin or methylated ubiquitin (MeUb).