Question

This process involves UP-frameshift proteins (UPFs: UPF1, UPF2, and UPF3). This process relies on reversible phosphorylation of UPF1 (switch) happens during a pioneer round of translation, likely so that aberrant transcripts are eliminated before mass translation is engaged.

A) Nonsense-Mediated Decay (NMD)
B) Exosomal Decay
C) Internal Decay
D) ARE-Mediated Decay

Answer 1

The process involving UP-frameshift proteins (UPFs) and reversible phosphorylation of UPF1 during a pioneer round of translation is associated with Nonsense-Mediated Decay (NMD), a cellular mechanism to prevent the synthesis of faulty proteins by degrading aberrant mRNAs. The correct option is A.

Step-by-step explanation:

The process described in the question involves UP-frameshift proteins (UPFs), which are fundamental components of the Nonsense-Mediated Decay (NMD) mechanism. This cellular mechanism is crucial for surveilling mRNA and identifying and degrading ones that contain premature termination codons, preventing the synthesis of aberrant proteins.

Key to this surveillance mechanism is reversible phosphorylation of UPF1, which acts as a switch during a pioneer round of translation. The eukaryotic mRNA lifecycle including 5' capping, polyadenylation, and the roles of mRNA in the ribosome are critical for proper translation and NMD recognition.