messengerRNS

Messenger RNA (mRNA) is a single-stranded RNA molecule that conveys genetic information from DNA to the ribosome, where it specifies the amino acid sequence of a protein. In most organisms, mRNA is transcribed from a gene and carries a coding message in a linear nucleotide sequence. In eukaryotes, mRNA features a 5' cap, a 5' untranslated region, a coding sequence, a 3' untranslated region, and a poly(A) tail. The cap and tail enhance stability and translation, while the untranslated regions regulate localization, stability, and efficiency of translation. Prokaryotic mRNAs generally lack the 5' cap and poly(A) tail and can be polycistronic, encoding multiple proteins.

Biogenesis begins with transcription by RNA polymerase II in eukaryotes, followed by processing steps: 5' capping, splicing to remove introns, and 3' polyadenylation. The mature mRNA is exported to the cytoplasm.

In the cytoplasm, ribosomes translate the coding sequence from start codon to stop codon, guided by codon–anticodon interactions with transfer RNAs. Translation efficiency is influenced by codon usage, regulatory sequences such as the Kozak consensus in eukaryotes, and various RNA-binding proteins. mRNA stability is controlled by sequences in the untranslated regions and interactions with microRNAs and RNA-binding factors; some transcripts undergo quality-control pathways such as nonsense-mediated decay.

mRNA is central to gene expression and biotechnological applications. Synthetic mRNA is used in vaccines and therapeutics, and in vitro transcription enables production of mRNA for research or medical use. The concept of messenger RNA gained prominence in the 1960s as a distinct molecule in the flow of genetic information.