11.   Proteasome is most active in the budding phase of making a new HIV viral particle.

12.   During budding, a new viral particle wraps itself in a membrane from the surface of the infected cell and completes its development.

13.   The researchers found that HIV uses the proteasome molecules, particularly ubiquitin, to complete the assembly of a new viral particle at the cell membrane.

14.   Without the enzyme, the virus only makes non-infectious viral particles.