What is the primary mechanism by which cells regulate protein degradation?

A Ubiquitin-proteasome pathway ✓
B Lysosomal degradation
C Autophagy
D Proteolytic enzyme activation

Explanation

The ubiquitin-proteasome pathway is a key mechanism by which cells regulate protein degradation, involving the tagging of proteins with ubiquitin molecules and their subsequent degradation by proteasomes.

Mnemonic

Ubiquitin = 'ubiquitous' protein tag

Source

Alberts et al., Molecular Biology of the Cell
Protein Metabolism Biochemistry Protein Degradation Medium MEDICAL Confidence: high