What happens to membrane proteins that have been attached to a single ubiquitin molecule?
A)They are selectively incorporated into endocytic vesicles.
B)They move immediately to proteasomes.
C)They stay in the membrane.
D)They move to the rough endoplasmic reticulum.
E)They move directly to the smooth endoplasmic reticulum.

Question

Quizplus · Accepted Answer

Proteins that have been attached to a single ubiquitin molecule are recognized by endocytic proteins and selectively incorporated into endocytic vesicles. This process is part of the ubiquitin-proteasome system where proteins marked with ubiquitin are degraded by proteasomes. However, a single ubiquitin molecule is not enough to trigger immediate degradation by proteasomes. Instead, it serves as a signal to be routed to endocytic pathways. Therefore, the proteins remain in the membrane until they are internalized by endocytosis.

What Happens to Membrane Proteins That Have Been Attached to a Single