Why is ubiquitin nicknamed the "doom tag"?
A) When ubiquitin binds to a target protein, the ubiquitin enzyme degrades the protein.
B) When ubiquitin binds to a target protein, the complex is sent to the proteasome and degraded.
C) If a cell is deficient in ubiquitin, the cell will die.
D) High levels of ubiquitin in a cell cause the cell to destroy vital proteins, leading to premature cell death.
E) Ubiquitin binds to ribosomes and prevents them from translating proteins necessary for cell survival.

Question

Quizplus · Accepted Answer

Ubiquitin is referred to as the "doom tag" because when it binds to a target protein, that complex is recognized by the proteasome, which then degrades the tagged protein. This process is a key regulatory mechanism to control the levels of various proteins within the cell, ensuring damaged or unneeded proteins are broken down.

Why Is Ubiquitin Nicknamed the "Doom Tag