In the autophagy sequence, what step immediately follows phagophore formation?

In the autophagy sequence, what step immediately follows phagophore formation?

• A. Nucleation
• B. Fusion with lysosome
• C. Autophagosome formation
• D. Degradation

Answer: (C)

The process being tested is the sequence of events in autophagy after the isolation membrane (phagophore) forms. Once the phagophore appears, it rapidly expands and closes to become a complete autophagosome, a double-membrane vesicle that enwraps the cargo. This autophagosome then fuses with a lysosome to form an autolysosome, where the contents are degraded. So the step right after phagophore formation is autophagosome formation. Nucleation relates to the initial formation of the phagophore itself, and degradation occurs later after fusion with lysosomes.

The process being tested is the sequence of events in autophagy after the isolation membrane (phagophore) forms. Once the phagophore appears, it rapidly expands and closes to become a complete autophagosome, a double-membrane vesicle that enwraps the cargo. This autophagosome then fuses with a lysosome to form an autolysosome, where the contents are degraded. So the step right after phagophore formation is autophagosome formation. Nucleation relates to the initial formation of the phagophore itself, and degradation occurs later after fusion with lysosomes.