The secretion proteins have to be folded correctly to get out of the ER. However, proteins that do not fold properly in ER undergo proteosomal destruction. How is it determined that proteins will be destroyed in this way?
Proteosomal destruction or degradation is achieved in the cell by special protein complexes called proteasomes. The proteasomes break the protein molecules by hydrolyzing the peptide bonds. The proteasomes attach to the protein molecule that has to be destroyed, by an ATP dependent process that involves three enzymes.
Proteins are marked for destruction when ubiquitin [Ub] attaches to the amino group of the side chain of a lysine residue with the help of enzymes called ubiquitin ligases. Additional Ub are then added to form a multiubiquitin chain. These poly-ubiquinated proteins are recognized and degraded by the proteasomes.
Get Answers For Free
Most questions answered within 1 hours.