Most proteins in eukaryotic cells are degraded by a highly selective non-lysosomal pathway that requires @entity855 and a large multicatalytic proteinase complex known as the 26S proteasome. In the present study, we evaluated the possibility that the proteasome-mediated pathway is involved in the regulation of laccase production by the efficient lignin-degrading basidiomycete Trametes versicolor in response to @entity3409 . These studies were performed using @entity16626 and @entity53562 as specific proteasome inhibitors separately added to the culture medium of 7-day-old mycelia of T. versicolor at the start of incubation with 10-200 muM @entity10278 . We found that @entity3280 stimulated laccase activity at all concentrations tested. The highest increase was observed at 100 muM @entity3280 , where laccase activity was three to fivefold higher than in @entity3280 -free cultures. Blocking of proteasome function in @entity3280 -supplemented cultures resulted in the considerably lower laccase activity in comparison to controls with no proteasomal inhibitor added. The decline of extracellular laccase activity triggered by the proteasome inhibitors was especially significant in the case of cultures with 100 muM @entity3280 , where around seven and threefold lost of laccase activity was observed for @entity16626 and @entity53562 , respectively. Similar findings were obtained for intracellular laccase. In contrast to @entity3280 -supplemented cultures, no significant change in laccase activity could be detected for @entity3280 -free cultures after exposure to the proteasome inhibitors. Effects observed with @entity503 , the inhibitor of lysosomal proteolysis, added to T. versicolor cultures were markedly different from those found in the case of the proteasome inhibitors. We also showed that addition of @entity3280 to growing cultures of T. versicolor did not significantly affect proteasome activities detected in high molecular (above 500 kDa) fractions of mycelial extracts. Our results strongly support the interpretation that the proteasome-mediated proteolytic pathway plays an important role in the regulation of T. versicolor laccase activity in response to @entity3280 .

Inhibition of the proteasome strongly affects XXXX stimulated laccase activity in Trametes versicolor.

@entity3280 :: ('CHEBI:48775', 'Chemical') :: ['Cd(2+)'] @entity16626 :: ('MESH:C072553', 'Chemical') :: ['MG132'] @entity3409 :: ('MESH:D002104', 'Chemical') :: ['cadmium'] @entity53562 :: ('MESH:C488643', 'Chemical') :: ['lactacystin beta-lactone'] @entity503 :: ('MESH:D002738', 'Chemical') :: ['chloroquine'] @entity10278 :: ('MESH:D019256', 'Chemical') :: ['CdCl(2)'] @entity855 :: ('MESH:D000255', 'Chemical') :: ['ATP']
@entity3409 :: (MESH:D002104,Chemical) :: ['cadmium']
