Significance of Export Factor Position on mRNA Explained

Scientists at the University of Sheffield say they have uncovered a key step in the production of proteins from genes, specifically how cells know when mRNA are ready to be transported. These findings could help our understanding of some cancers and conditions such as motor neuron disease, which are linked to faults in protein production.

According to Stuart Wilson, lead researcher on a paper published in Molecular Cell today, "If the mRNA is transported before the processing is complete, then it is a disaster for the cell, which can't make proteins and ultimately dies. Faults in this process are behind many human diseases. So it's vitally important, not just that the processing is done correctly, but the cell knows when this is complete."

The team found that molecules known as 'export factors'—which help transport the mRNA—also signal to the cell when the processing is complete by moving their position on the mRNA. Scientists have long argued over the position of export factors—whether they sit at the beginning of the mRNA or centrally, where the protein-making instructions have been spliced together.

Professor Wilson and his colleagues found that in fact, both views are correct. The export factors initially sit at the beginning of the mRNA while the processing takes place, then once it is complete, they move further in, sitting at points where splicing has taken place, to signal that transport can begin.

"This research helps us understand a basic process that is fundamental to life, but which will enable us to develop treatments for diseases in the future," said Professor Wilson. "We can't easily fix a problem until we know what's wrong and we can't know what's wrong until we're clear as to how it's supposed to work.