MRNA Editing

Regulation of Protein Synthesis

Overview

• The process of regulating protein synthesis includes various steps, primarily focused on mRNA editing.

mRNA Editing

• Purpose:

  • Energy Conservation: The process conserves energy by ensuring that only necessary proteins are synthesized.

  • Preventing Degradation: By modifying mRNA, cells prevent its degradation and ensure stable expression of genes.

• Location:

  • mRNA editing occurs in the cytoplasm.

Key Terms in mRNA Editing

• Step 1 Capping:

  • The addition of a 5' cap to the 5' end of pre-mRNA.

  • The cap protects the mRNA from degradation

• Step 2 Poly-A Tail:

  • A long chain of adenine nucleotides is added to the 3' end of the pre-mRNA.

  • Regulates how much protein is made

• Step 3 Splicing:

  • The process of removing introns (non coding regions) and joining exons (coding regions) done by spliceosome together to form a mature mRNA.

Eukaryotic Specifics

• The processes of capping, polyadenylation, and splicing are primarily found in Eukaryotic organisms.

Summary of Key Points

• This editing process results in a linear mRNA strand after introns are removed, leaving only exons that code for proteins.

• Does this process occur in prokaryotes (bacteria)?

  • No, these specific mRNA editing processes do not occur in bacteria, as they do not possess introns and generally have a more direct mRNA to protein translation process than eukaryotes.