What increases the half-life of mRNA?

The half-life of mRNA refers to the duration for which an mRNA molecule remains stable and functional within the cell before it is degraded. The presence of a 5' methyl cap is crucial for increasing the stability and half-life of mRNA molecules.

The 5' methyl cap, which consists of a modified guanine nucleotide, serves several important roles in mRNA metabolism. It protects the mRNA from degradation by exonucleases, as the cap structure makes it more resistant to enzymatic attack. Additionally, the methyl cap plays a critical role in the initiation of translation, as it helps ribosomes recognize and bind to the mRNA for protein synthesis. By facilitating these protective and functional roles, the 5' methyl cap directly contributes to a longer half-life of mRNA in the cytoplasm.

In contrast, while the 5' poly-A tail also provides stability and extends the half-life of mRNA, the focus in the question is on the cap structure. RNA polymerase, on the other hand, is the enzyme responsible for synthesizing mRNA but does not directly influence the mRNA half-life after transcription. Translation initiation involves the assembly of the ribosomal machinery on the mRNA, which is more related to the function of