Biochemistry Questions / Explain the process of mRNA export and the role of NXF1 and Ref in mediating this process.

mRNA export from the nucleus occurs through nuclear pore complexes (NPC), requiring NXF1 and Ref to allow mRNA to be exported.

NXF1 is an export factor required to allow mRNA to be transported out of the nucleus. This was discovered by isolating nuclei by using digitonin to solubilise cell walls, changing the contents of the extranuclear fluid: when NXF1 was absent, mRNA built up within the nucleus (which was demonstrated by fluorescence in situ hybridisation (FISH) staining of transcripts).

Ref facilitates NXF1 binding to the mRNA, and is deposited onto the mRNA during splicing. This enables nuclear export, preventing the export of pre-mRNA.