Question

Based on the information provided, what can you conclude about the drug that blocks the activity of one of the enzymes involved in ubiquitylation of proteins?

1) The drug blocks the activity of Ubiquitin Activating Enzyme (E1)
2) The drug blocks the activity of a Ubiquitin E2 protein
3) The drug blocks the activity of a Ubiquitin E3 protein
4) Protein synthesis is increased by the drug treatment

Answer 1

The drug that blocks the activity of one of the enzymes involved in ubiquitylation of proteins is most likely blocking the activity of a Ubiquitin E3 protein(option 3).

Step-by-step explanation:

The drug that blocks the activity of one of the enzymes involved in ubiquitylation of proteins is most likely blocking the activity of a Ubiquitin E3 protein.

Ubiquitin E3 proteins are responsible for recognizing and binding to target proteins, tagging them with ubiquitin molecules, and facilitating their degradation by the proteasome. When the drug inhibits the activity of a Ubiquitin E3 protein, it prevents the target protein from being tagged with ubiquitin, leading to a decrease in protein degradation.

This conclusion is supported by the information provided in the references. The first step in the ubiquitylation process involves the activation of ubiquitin by the Ubiquitin Activating Enzyme (E1), followed by the transfer of ubiquitin to the target protein by the Ubiquitin-Conjugating Enzyme (E2).

The specificity of protein degradation is controlled by Ubiquitin E3 proteins. Additionally, the information about inhibitors of protein synthesis and antibiotics that block protein synthesis is not directly relevant to ubiquitylation of proteins.