Question

-What is the process by which proteins can become ubiquinated or sumoylated and what typically happens to the modified protein? Describe the process of protein degradation.

-Detail how the various modifications of a protein may target it to different compartments within or outside of the cell.

-Detail the specific effects of a defect in the cellular post translational protein processing system and what effect it may have on the cell.

Answer 1

• The process through which proteins become ubiquitinated / sumoylated is through reversible post translational modification.
• Sumoylation involve covalent modification of lysine residues on targeted proteins.
• Ubiquitin proteasome pathway involve protein degradation, where protein to be degraded has been tagged with ubiquitin. This ubiquitin gets attached to the lysine residue of the protein. Ubiquitin ligase through ubiquitination involves protein degradation.
• Ubiquitin proteasome pathway degrades proteins from cytoplasm, Endoplasmic reticulum and nucleus.