2 research outputs found
Subunit-selective proteasome activity profiling uncovers uncoupled proteasome subunit activities during bacterial infections
The proteasome is a nuclearâcytoplasmic proteolytic complex involved in nearly all regulatory pathways in plant cells. The three different catalytic activities of the proteasome can have different functions, but tools to monitor and control these subunits selectively are not yet available in plant science. Here, we introduce subunitâselective inhibitors and dualâcolor fluorescent activityâbased probes for studying two of the three active catalytic subunits of the plant proteasome. We validate these tools in two model plants and use this to study the proteasome during plantâmicrobe interactions. Our data reveal that Nicotiana benthamiana incorporates two different paralogs of each catalytic subunit into active proteasomes. Interestingly, both β1 and β5 activities are significantly increased upon infection with pathogenic Pseudomonas syringae pv. tomato DC3000 lacking hopQ1â1 [PtoDC3000(ÎhQ)] whilst the activity profile of the β1 subunit changes. Infection with wildâtype PtoDC3000 causes proteasome activities that range from strongly induced β1 and β5 activities to strongly suppressed β5 activities, revealing that β1 and β5 activities can be uncoupled during bacterial infection. These selective probes and inhibitors are now available to the plant science community, and can be widely and easily applied to study the activity and role of the different catalytic subunits of the proteasome in different plant species.Bio-organic Synthesi