Question

Phosphorylation of serine residue on the eIF2 bound to GDP results in:

• A. Initiation of protein synthesis
• B. Inhibition of protein synthesis
• C. Inhibition of DNA synthesis
• D. Initiation of RNA synthesis

Hint:

Phosphorylation of eIF2 on serine residues leads to inhibition of translation initiation, halting protein synthesis.

Answer 1

The Correct Option is B

Step 1: Understanding eIF2 Function 
eIF2 (eukaryotic initiation factor 2) plays a key role in the initiation of protein synthesis by binding to GTP and initiating the formation of the translation initiation complex. 
Step 2: Role of Phosphorylation 
Phosphorylation of eIF2 on serine residue, specifically when bound to GDP, results in the inhibition of its ability to participate in translation initiation. 
Step 3: Conclusion 
Thus, phosphorylation of eIF2 inhibits protein synthesis.