Final answer:
Messenger RNA (mRNA) is transported out of the nucleus after transcription. A cap and tail regulate its exit via proteins that guide it through nuclear pore complexes, readying mRNA for subsequent translation in the cytoplasm.
Step-by-step explanation:
Following transcription, messenger RNA (mRNA) must be transported out of the nucleus through the nuclear pore complexes. The 5' methyl guanosine cap and the poly(A) tail are critical to this process, aiding in the mRNA's exit from the nucleus into the cytoplasm. Proteins in the nucleus, such as the nuclear transport receptor and poly-A-binding proteins, assist in the export process by binding to the mature mRNA and guiding it through the nuclear pores. Once in the cytoplasm, these binding proteins are replaced, and the mRNA is ready for translation, the synthesis of proteins directed by the genetic code.
Eukaryotic primary transcripts undergo several processing steps to become mature mRNAs, which are then protected from degradation and transported from the nucleus to the cytoplasm for protein synthesis. This export mechanism is vital as it allows for the proper expression of genetic information and the consequent synthesis of proteins that sustain cellular and organismal functions.