The ubiquitin-proteasome pathway (check all that apply)
A)is used to regulate expression of a number of cell surface receptors.
B)requires only one molecule of ATP to target a protein.
C)targets proteins in a stepwise fashion via ubiquitin ligase adding ubiquitin residues to the protein.
D)is used to digest macromolecules.
E)does not destroy the ubiquitin moiety,but rather cleaves it off for reuse.

Question

Quizplus · Accepted Answer

The ubiquitin-proteasome pathway regulates protein degradation, including cell surface receptors, by tagging them with ubiquitin. Ubiquitin ligase adds ubiquitin residues in a stepwise manner. The ubiquitin moiety is cleaved off and reused, not destroyed.

The Ubiquitin-Proteasome Pathway (Check All That Apply)