What is the primary function of the 3' untranslated region (3' UTR) in mRNA?

The primary function of the 3' untranslated region (3' UTR) in mRNA is to protect the mRNA from degradation. The 3' UTR is crucial for the stability of mRNA molecules, as it contains elements that interact with proteins and RNA-binding factors, which can influence the longevity of the mRNA in the cytoplasm. These interactions help to prevent the mRNA from being rapidly degraded by cellular enzymes.

Additionally, the 3' UTR can also play roles in the regulation of gene expression, including controlling the translation of the mRNA and its localization within the cell. Structures such as polyadenylation signals and specific binding sites for regulatory proteins within the 3' UTR contribute significantly to the overall stability and functional lifespan of the mRNA after it has been transcribed. Consequently, the 3' UTR is key in ensuring that the mRNA remains intact for translation and contributes effectively to protein synthesis.