Gatekeeping proteins to aberrant RNA—“You shall not pass“

Mistakes happen. This is the case in the process of transporting genetic information in cells. How our cells keep errors in this process in check is the subject of a new paper by researchers at the Department of Energy’s Lawrence Berkeley National Laboratory (Berkeley Lab). 

They found that RNA-binding proteins are regulated such that gateway proteins can recognize and block aberrant strands of genetic code from exiting the nucleus. Unused messenger RNA (mRNA) strands that cannot exit the nucleus would eventually disintegrate.

Their findings, published today in the journal Scientific Reports, shed light on a complex system of cell regulation that acts as a form of quality control for the transport of genetic information out of the nucleus.

Getting a more complete picture of how genetic information gets expressed in cells is important in disease research, the researchers said.

“Some components of this machinery are dysregulated in various types of cancers,” said study principal investigator Mohammad Mofrad, faculty scientist at Berkeley Lab’s Molecular Biophysics and Integrated Bioimaging Division. “Understanding the molecular mechanism of genetic information transport and quality control would substantially improve the current knowledge about various types of cancers and other human diseases.”

Biology textbooks already describe how strands of mRNA copy sections of DNA inside a cell’s nucleus and then exit to the cell’s cytoplasm. It is in the cytoplasm where the genetic code is used to synthesize proteins, so ensuring that only the correct mRNA strands get used is critical to the formation of properly functioning proteins.

“Just like all production lines, the process of genetic information transfer and protein production is quality controlled at different stages,” said Mofrad. “To date, the exact mechanism of this quality control step has remained unclear.”