Like Proteasome it exhibits a barrel-like architecture that appears to have evoled to restrict substrate access and prevent indiscriminate degradation.
proteasome | Proteasome |
In molecular biology, the DSS1/SEM1 protein family is a family of short acidic proteins which includes the 26S proteasome complex subunits SEM1 from Saccharomyces cerevisiae and Drosophila and DSS1 (SHFM1) in mammals.
Interaction with CHIP (Carboxyl-terminus of Hsp70 Interacting Protein)–an E3 ubiquitin ligase–allows Hsp70 to pass proteins to the cell's ubiquitination and proteolysis pathways.
The hsrω-n transcript directly or indirectly affects the localization/stability/activity of a variety of proteins including hnRNPs, Sxl, Hsp83, cAMP response element binding binding protein (CBP), Drosophila inhibitor of apoptosis protein 1 (DIAP1), JNK-signalling members, proteasome constituents, lamin C, ISWI, HP1 and poly(ADP)-ribose polymerase.
IgG also plays an important role in antibody-dependent cell-mediated cytotoxicity (ADCC) and intracellular antibody-mediated proteolysis, in which it binds to TRIM21 (the receptor with greatest affinity to IgG in humans) in order to direct marked virions to the proteasome in the cytosol.
Intracellular antibody-mediated degradation (IAMD) is a neutralization mechanism of intracellular antibody-mediated immunity whereby an effector protein, TRIM21, directs antibody bound virions to the proteasome where they are degraded.
This protein is a target for SMAD-specific E3 ubiquitin ligases, such as SMURF1 and SMURF2, and undergoes ubiquitination and proteasome-mediated degradation.
Cytoplasmic complexes, called proteasomes, digest older or abnormal proteins that have been tagged with ubiquitin for destruction.
ER-proteins are degraded in the cytosol by the 26S proteasome, a process known as Endoplasmic-reticulum-associated protein degradation, and therefore have to be transported by an appropriate channel.