Fig 3.

MEC217 and MEC217-PI31 cells were cultured in the absence of TET for 1 day to induce immunosubunit expression and then labeled for 4 h with [³⁵S]Met and extracted. Detergent lysates were centrifuged on glycerol gradients (10–40%) and collected as 600-μl fractions. Proteasome complexes were immunoprecipitated from the fractions, separated by NEPHGE-SDS/PAGE two-dimensional gel electrophoresis, and visualized by autoradiography; the subunits were assigned according to Elenich et al. (35).