Can RNA Leave The Nucleus? 9 Facts You Should Know

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RNA is a nucleic acid which is the genetic material in few of the organisms. Let us now have a brief overview on RNA that leaves the nucleus.

RNA leaves the nucleus after it is being synthesized and work on its assigned mechanism outside of the nucleus. RNA are produced inside the nucleus. After synthesis they need to exit from the nucleus and enter the other organelle for processes like translation etc.

The full form of RNA is ribonucleic acid, which is present in each and every living cell. Its major role is to carry out the translation process in which the polypeptide chain (proteins) is synthesized.

When does RNA leave the nucleus?

RNA is a nucleic acid which is the genetic material in few of the organisms. Let us now have a brief overview on RNA that leaves the nucleus.

The RNA leaves the nucleus when there is a need of any amino acid to be produced or if the translation process needs to be initiated. The newly synthesized ribonucleic acid leaves the nucleus and enters the cytoplasm, from where they are adhered on the ribosomes.

Why does RNA leave the nucleus?

RNA spends most of its time in the cytoplasmic region. Let us know the reason behind this.

RNA leaves the nucleus so that it starts to work for what it has been synthesized (the purpose). RNA does not perform any other functions inside the nucleus besides synthesis. Once RNA is synthesized, it is immediately transported to the cytoplasmic membrane where they perform their actual task.

How does RNA leave the nucleus?

The RNA must escape from the nucleus and enter into the cytoplasm. Let us see how RNA leaves the nucleus.

  • After the synthesis of the newly synthesized RNA or the ribonucleic acid, the RNA has to leave the nucleus and enter into the cytoplasm. This is done by the help of a protein called the mRNP (Messenger Ribonucleic Acid Protein).
  • The mRNP is called the transport protein here. The mRNP mixes or attaches itself into the newly synthesized RNA and their journey towards the outer layer of the nucleus takes place.
  • The outer layer of the nucleus is called the nuclear pore which has many pore or holes like structures for the components to go in and out of the nucleus. The nuclear membrane is very specific at letting in and out particles.
  • The newly formed RNA molecule and the mRNP transport protein combine and mix with the content that is present inside the nucleus so that they can escape the nuclear pore better.
  • The RNA molecule has 2 regions in them, one is the coding and non coding. The non-coding sequence region is of no use when entering the cytoplasm as they do not take part in the translation process.
  • Before the complete elimination of the RNA from the nucleus, there needs to be a process called the RNA processing. It is a process in which the non coding region (the introns) are removed or eliminated and the remaining coding sequence (exons) are completely attached together.

After this process, the RNA leaves the nucleus with the aid of the mRNP through the nuclear pore present inside the nuclear membrane.

What type of RNA leave the nucleus?

There are different types of RNA based on their functionalities. Let us now see which type of RNA leaves the nucleus.

The type of RNA that leaves the nucleus is the messenger RNA or the mRNA. The transcription process takes place in the nucleus in which the DNA is converted to the mRNA. Further, the newly synthesized mRNA has to leave the nucleus and undergo the translation process, which happens in the cytoplasm.

can rna leave the nucleus
Translation
Image Credits- Wikimedia

Can RNA go back to the nucleus?

Various research has been going on to understand the concept of the RNA re-entry to nucleus and here is what the current research says.

As per a scientific trial (Nuclear Export of Messenger RNA), it is said that the RNA can go back into the nucleus. The findings show that the RNA once being transported to the cytoplasm from the nucleus, must proceed with translation or else the RNA gets back to the nucleus again.

Once the RNA re-enters into the nucleus, eventually no amino acids will be coded and thus the translation process will be terminated.

What happens during RNA processing before it can leave the nucleus?

RNA once being synthesized will not get its final form to get into the translation process, it needs to be modified. Let us see how the RNA is being modified.

RNA processing is done when the RNA is spliced or cut in such a way, they can be easily used during the translation process. The RNA has 2 regions, the coding and non-coding. The non-coding region is removed, and the coding region is attached together thus making it perfect for the translation process.

The RNA processing is also called the post transcriptional modification, which happens only in eukaryotes and the enzyme used for splicing is called the spliceosome.

Can RNA move between the nucleus and the cytoplasm?

The nucleus is surrounded by a thick outer layer called the nuclear membrane. Let us see if RNA can move between the nucleus and the cytoplasm.

RNA can move between the nucleus and the cytoplasm. The nuclear membrane has numerous pores on the surface for the content in the cell as well as for nucleus to enter and exit. RNA with the help of mRNP enters and exits nucleus through the nuclear pore present on the surface of the nuclear membrane.

What must happen before mRNA can leave the nucleus?

The messenger RNA is synthesized inside the nucleus from the DNA strand. Let us see what happens to the mRNA before it leaves the nucleus.

Before mRNA leaves the nucleus, it must undergo a modification process called the post transcription modification. The DNA strand transcripts itself and produces the mesenger RNA. Now this mRNA will be in a crude form which needs to be processed so the post transcriptional modification takes place.

This is a process in which the unwanted parts in the RNA are cut out and the region which aids in the amino acid synthesis are being combined and thus the mRNA comes out of the nucleus.

What happens after the mRNA goes out of the nucleus?

We know that mRNA is synthesized inside the nucleus. Let us see what happens to the mRNA after the synthesis.

The mRNA gets out of the nucleus and enters the cytoplasm where it is bound to the ribosomes and performs the translation process. After the transcription process, the purpose of the newly synthesized messenger RNA molecules is to code for the amino acids. Hence, mRNA performs the translation process.

Conclusion:

To conclude the article, “Can RNA Leave The Nucleus? 9 Facts You Should Know”, we now have a detailed idea on the RNA which is being synthesized inside the nucleus, what is their next job when they leave the nucleus and also on their modification before they enter the cytoplasm.

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