BioCoach Activity

Concept 10: Pre-mRNA Processing (Splicing)

Eukaryotic pre-mRNAs typically include introns. Introns are removed by RNA processing in which the intron is looped out and cut away from the exons by snRNPs, and the exons are spliced together to produce the translatable mRNA.

The steps of pre-mRNA splicing (intron removal) are as follows:

  • The intron loops out as snRNPs (small nuclear ribonucleoprotein particles, complexes of snRNAs and proteins) bind to form the spliceosome.
  • The intron is excised, and the exons are then spliced together.
  • The resulting mature mRNA may then exit the nucleus and be translated in the cytoplasm.