Figure 2.

Schematic representation of the intracellular proteostasis network. Cytosolic misfolded proteins are bound by molecular chaperones, such as the HSPs. Molecular chaperones may act as aggregate unfolding and refolding enzymes. Autophagy pathways (chaperone-mediated, micro- and macroautophagy) degrade misfolded proteins. Ubiquitinated proteins are degraded by the ubiquitin-proteasome system. Sequestration of degraded misfolded proteins may form compact aggresomes and IPODs. Proteasome resistant aggresomes become enveloped by autophagosome membranes and transported into the lysosomes for autophagy.