Proteasome activity in PaCSs of living cells.

<p>(<b>A</b>) Proteasome chimotrypsin-like activity shown by TED peptide cleavage in living HeLa cells concentrated in cytoplasmic bodies resembling PaCSs in size and intracellular distribution, and (<b>A1</b>) was greatly reduced by epoxomicin treatment. (<b>A2</b>) No comparable fluorescent areas appeared in the cytoplasm of TED-incubated living COS-7 cells. (<b>B</b>) TED-induced proteasome fluorescent bodies in two living HeLa cells under confocal microscopy corresponding in an aldehyde–osmium-fixed resin TEM section of the same cells (<b>B1</b>) to clear spots identified as PaCSs at higher resolution, owing to their faintly contrasted barrel-like particles and selective FK1 immunoreactivity, as shown in (<b>b2</b>) and (<b>b3</b>) for the one arrowhead in (<b>B</b>) and (<b>B1</b>).