What happens to an mRNA during RNA processing in eukaryotes?
Introns are removed and degraded while the pre-mRNA is still in the nucleus. Splicing occurs by a sequence-specific mechanism that ensures introns will be removed and exons rejoined with the accuracy and precision of a single nucleotide.
Where does RNA processing occur in eukaryotes?
In eukaryotic cells, RNA synthesis, which occurs in the nucleus, is separated from the protein synthesis machinery, which is in the cytoplasm.
Where does the process of mRNA splicing occur in eukaryotes?
For nuclear-encoded genes, splicing takes place within the nucleus either during or immediately after transcription. For those eukaryotic genes that contain introns, splicing is usually required in order to create an mRNA molecule that can be translated into protein.
Why is mRNA processed in eukaryotes?
Eukaryotic mRNA precursors are processed by 5′ capping, 3′ cleavage and polyadenylation, and RNA splicing to remove introns before being transported to the cytoplasm where they are translated by ribosomes. Nascent pre-mRNA transcripts are associated with a class of abundant RNA-binding proteins called hnRNP proteins.
What happens in mRNA processing?
The process of removing introns and reconnecting exons is called splicing. Introns are removed and degraded while the pre-mRNA is still in the nucleus. Splicing occurs by a sequence-specific mechanism that ensures introns will be removed and exons rejoined with the accuracy and precision of a single nucleotide.
Why does eukaryotic mRNA need processing?
Eukaryotic mRNAs must undergo several processing steps before they can be transferred from the nucleus to the cytoplasm and translated into a protein. The additional steps involved in eukaryotic mRNA maturation create a molecule that is much more stable than a prokaryotic mRNA.
What are the three steps in mRNA processing?
In this section, we take a closer look at how eukaryotic cells carry out mRNA processing, which includes three major processes: 5′ capping, 3′ cleavage/polyadenylation, and RNA splicing (Figure 11-7).
What are the 3 parts of mRNA?
Protein Synthesis and Folding* mRNAs have three parts: Nucleotides at the 5′ end provide binding sites for proteins that initiate polypeptide synthesis; nucleotides in the middle specify the sequence of amino acids in the polypeptide; and nucleotides at the 3′ end regulate the stability of the mRNA (Fig. 1.1).