The development history of the mRNA cap stems from in-depth research into gene expression in eukaryotes. The mRNA cap is a modification at the 5' end of mRNA molecules, playing a crucial role in translation, stability, and immune response. In the early 1970s, scientists first discovered the capping structure at the 5' end of eukaryotic mRNA. This cap consists of a 7-methylguanosine (m7G) linked to the mRNA via a 5'-5' triphosphate bond. Scientists later discovered that the mRNA cap not only includes the basic m7G structure but can also have methylations on nearby nucleotide residues, forming more complex Cap 1 and Cap 2 structures. These modifications increased mRNA stability and reduced immune system recognition of exogenous mRNA. Cap 1 and Cap 2 are widely used in the synthesis of mRNA for vaccines and gene therapies.
