​The table provides protein modifications (Column X) and their functions (Column Y)

Which one of the following options represents all correct matches between Column X and Column Y?

Correct option is C

​Explanation :

1. Palmitoylation → Membrane Anchoring (ii)
• Palmitoylation adds a fatty acid (palmitate) to proteins, making them hydrophobic and anchoring them to the membrane.
• Commonly found in membrane proteins and signaling molecules.
2. polySUMOylation → Protein Degradation (i)
• SUMOylation (Small Ubiquitin-like Modifier attachment) regulates protein stability, degradation, and nuclear transport.
• It plays a role similar to ubiquitination, tagging proteins for degradation or cellular localization.
3. Glycosylphosphatidylinositol (GPI) Anchor → Membrane Anchoring (ii)
• GPI anchors tether proteins to the outer membrane of the plasma membrane.
• Essential for signaling proteins and lipid raft-associated proteins.
4. Mannose-6-phosphate → Lysosomal Targeting (iii)
• Mannose-6-phosphate (M6P) tags proteins for transport to lysosomes.
• Lysosomal hydrolases receive this modification in the Golgi apparatus, allowing recognition by M6P receptors

Information Booster:

1. Post-translational modifications (PTMs) regulate protein function, localization, and degradation.
2. Palmitoylation and GPI anchoring ensure proteins are membrane-bound.
3. SUMOylation is involved in nuclear transport, transcription regulation, and proteasomal degradation.
4. Mannose-6-phosphate ensures proteins reach lysosomes, preventing lysosomal storage disorders.
5. Defects in lysosomal targeting (e.g., I-cell disease) result in severe metabolic dysfunctions.

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