Question

The deadenylation pathway is a critical means of maintaining a steady state level of mRNAs and proteins in the cells. How does deadenylation affect protein synthesis if it works on mRNAs?

A. loss of the poly A tail results in rapid 3'-5' degradation of transcript leading to reduced accumulation of the corresponding protein
B. deadenylation results in increased decapping and subsequent 5' mediated degradation
C. it reduces the formation of 5' 3' communication through the formation of circular mRNA structures

a and b only
a, b and c

Answer 1

Deadenylation affects protein synthesis by causing the mRNA molecule to degrade more rapidly, as it shortens the poly(A) tail which is critical for mRNA stability. This has downstream effects such as enhanced decapping and disrupted 5' to 3' communication that are vital for efficient translation, ultimately reducing protein synthesis.

Step-by-step explanation:

Deadenylation refers to the shortening of the poly(A) tail at the 3' end of an mRNA molecule. This process is critical for controlling mRNA stability and, consequently, protein synthesis. The poly(A) tail plays important roles such as assisting in mRNA export from the nucleus and preventing mRNA degradation in the cytoplasm. When the poly(A) tail is shortened through deadenylation:

• There is a loss of the poly(A) tail, which results in a rapid degradation of the transcript from the 3'-5' end, leading to a reduced accumulation of the corresponding protein.
• Deadenylation also results in increased decapping and subsequent 5' mediated degradation of the mRNA.
• It reduces the formation of 5' 3' communication through the circularization of mRNA structures. This is important as the circularization aids in the efficiency and stability of translation.

Therefore, the correct answers are a, b, and c.