• selection
• phage display
• ELISA

Accumulation of altered proteins in old animals has been ascribed also to slower turnover of proteins. Since proteasome is key intracellular protease involved in maintaining cellular homeostasis assuring the regular turnover of cellular proteins, and it is known to preserve its number and general composition in aged cells, but it is also known to decrease its activity, to know its behaviour in aging cells could give a different point of view on aging mechanisms.
The proteasome exists as different oligomeric assemblies defined by both the composition of the catalytic subunits (core) and the type of regulatory complex associated with the catalytic core. The regulatory complexes PA700 or PA28 in association with the 20S proteasome (the core) form respectively, the 26S constitutive proteasome or the immunoproteasome.
The constitutive catalytic subunits of 20S core can be replaced by inducible subunits, shifting from 26s constitutive to immuno-proteasome, as consequence of inflammatory stimuli, such as exposure to tumor necrosis factor α (TNFα) or interferon γ (IFNγ).
Precedent works revealed that in aging there is a similar shift even without a clear inflammatory signal. This study is part of the Integrated Project GEHA for identify genes involved in aging and longevity and its primary aim is to select antibodies against proteasome subunits to elucidate proteasome subunits behaviour in different aged cells, allowing visualization and quantification of specific proteasome subunit isoforms.