Part:BBa_K4829006
PolyA tail for an mRNA sequence.
This is simply a 100-base polyA tail. The length of the PolyA tail does affect expression, though the data on the relative efficiencies may be said to be inconclusive at the very least. The reason this tail is so essential is that the cell is not performing the concomitant tailing after transcription, and hence this must be done by us, either post-transcriptionally, or it must be incorporated in the plasmid in use.
Usage and Biology
Poly(A) tails are a distinctive feature of eukaryotic mRNAs and play a pivotal role in the post-transcriptional regulation of gene expression. Here's why Poly(A) tails are important:
- mRNA Stability: The Poly(A) tail protects mRNA from degradation. In the cytoplasm, exonucleases degrade mRNAs starting from their 3' ends. The Poly(A) tail acts as a buffer against this degradation, and as it gets shorter, the mRNA becomes more susceptible to degradation.
- Translation Efficiency: The Poly(A) tail facilitates the initiation of translation. Proteins called Poly(A) binding proteins (PABPs) bind to the Poly(A) tail. These proteins interact with the translation initiation complex at the 5' end of the mRNA, enhancing the efficiency of translation initiation and promoting the circularization of mRNA, which can further facilitate translation.
- Nuclear Export: The Poly(A) tail plays a role in the export of mRNA from the nucleus to the cytoplasm. Specific proteins recognize and bind to the Poly(A) tail, helping the mRNA to be transported out of the nucleus.
- mRNA Maturation: The addition of the Poly(A) tail is a critical step in mRNA maturation. It often follows splicing and precedes the exit of the mature mRNA from the nucleus.
- End Protection: The Poly(A) tail prevents the mRNA from being degraded by exonucleases, ensuring that the coding sequence of the mRNA remains intact for effective translation.
- Regulation of mRNA Half-Life: The length of the Poly(A) tail can influence the stability and half-life of an mRNA. Certain stimuli or conditions can lead to the shortening of the Poly(A) tail, marking the mRNA for rapid degradation.
- Role in Early Development: In certain organisms, like frogs, mRNAs stored in eggs are initially translationally inactive with short Poly(A) tails. Upon fertilization, these tails are lengthened, activating translation, which is crucial for early developmental processes.
Sequence and Features
- 10COMPATIBLE WITH RFC[10]
- 12COMPATIBLE WITH RFC[12]
- 21COMPATIBLE WITH RFC[21]
- 23COMPATIBLE WITH RFC[23]
- 25COMPATIBLE WITH RFC[25]
- 1000COMPATIBLE WITH RFC[1000]
Functional Parameters
We have used this part in BBa K4829003, and we noticed expression in Hela cells, 6hrs post-transfection.
Figure 1. Expression of the protein noted in the supernatant 6 hours post transfection
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