Which of the following is not associated with protein degradation?

• A. Ubiquitin-proteasome pathway
• B. Lysosomal pathway
• C. 5' Cap
• D. N-terminal degradation signal

Answer: (C)

Verified step by step guidance

1. Understand the context of protein degradation: Protein degradation is a crucial cellular process that involves breaking down proteins into their constituent amino acids. This process is essential for regulating protein levels and removing damaged or misfolded proteins.
2. Identify the pathways associated with protein degradation: The two main pathways for protein degradation in cells are the ubiquitin-proteasome pathway and the lysosomal pathway. Both pathways serve to degrade proteins but operate through different mechanisms.
3. Examine the ubiquitin-proteasome pathway: This pathway involves tagging proteins with ubiquitin molecules, marking them for degradation by the proteasome, a large protein complex that breaks down proteins into peptides.
4. Explore the lysosomal pathway: This pathway involves the degradation of proteins within lysosomes, which are organelles containing enzymes that break down various biomolecules, including proteins.
5. Recognize the unrelated term: The 5' Cap is a modification found on the 5' end of eukaryotic mRNA molecules, playing a role in mRNA stability and translation, not in protein degradation. Therefore, it is not associated with protein degradation.