Expert reviewed • 08 January 2025 • 7 minute read
Messenger RNA (mRNA) and transfer RNA (tRNA) are central intermediaries in protein production. They convert genetic instructions from DNA into polypeptides, ensuring that cells produce the proteins required for growth, function, and adaptation.
mRNA carries genetic information from DNA to the ribosome. It has a protective 5' cap aiding stability and ribosome binding, a coding region with the actual blueprint for protein synthesis, regulatory sequences (3' UTR), and a poly-A tail at the end that enhances stability and export.
| Feature | Function | Location |
|---|---|---|
| 5' Cap | Stability, ribosome binding | Start |
| Coding Region | Protein instructions | Middle |
| 3' UTR | Regulatory role | Before poly-A tail |
| Poly-A Tail | Stability, export | End |
Before mRNA can function properly, it undergoes capping, intron removal (splicing), and polyadenylation. These steps refine the initial transcript into a mature, functional molecule.
Key modifications include:
tRNA molecules have a distinctive cloverleaf shape, containing an anticodon region that pairs with mRNA codons and an acceptor stem that attaches a specific amino acid.
| Region | Function | Importance |
|---|---|---|
| Anticodon | Matches mRNA codon | Ensures accuracy |
| D-arm | Structural stability | Proper folding |
| T-arm | Ribosome recognition | Correct interaction |
| Acceptor stem | Amino acid binding | Protein assembly |
tRNA acts as an adaptor, translating the genetic code into amino acid sequences. By delivering the correct amino acids to the ribosome, tRNA ensures the protein is built according to the mRNA instructions.
During translation, mRNA codons align with tRNA anticodons. Ribosomes facilitate this interaction, moving along the mRNA, reading codons, and assembling the polypeptide chain. This coordinated process guarantees that proteins are synthesised accurately and efficiently.
Cells maintain rigorous quality control. Erroneous mRNAs are degraded, amino acids are checked before being attached to tRNA, and codon-anticodon pairing is closely monitored to prevent faulty protein production.
Gene expression can be fine-tuned at the translational level. Regulatory molecules, such as microRNAs, RNA-binding proteins, and certain enzymes, can alter mRNA stability or tRNA function to ensure proteins are synthesised only when and where they are needed.
Defects in mRNA or tRNA processing can lead to various conditions:
These insights guide better diagnosis, treatment, and drug development strategies.
Advances in understanding mRNA and tRNA have led to mRNA vaccines, improved gene therapies, and more precise diagnostic tools. By leveraging these molecules, researchers can develop novel treatments, preventive measures, and medical interventions.