University of Chicago researchers have identified yet another layer of complexity to how genes are expressed, with their discovery of the first human “bifunctional” gene—a single gene that creates a single mRNA transcript that codes for two different proteins, simultaneously. The study by Christopher Gomez, MD, and Xiaofei Du, MD, could lead to new treatments for ataxia type-6 (SCA6), a neurodegenerative disease that causes patients to slowly lose coordination of their muscles and eventually their ability to speak and stand.This newly discovered feat is accomplished by a special sequence that sits in the middle of the mRNA instead of the beginning, creating a second location for ribosomes, the cellular machines that read mRNA, to begin the process of protein production. Gomez and his team hope to discover other examples of human genes with similar sites to better understand the implications of this new class of “bifunctional” genes on our basic biology:
“This is the first example of a mechanism in a higher organism in which one gene creates two proteins from the same mRNA transcript, simultaneously,” said Christopher Gomez, MD, PhD, professor and chairman of the Department of Neurology at the University of Chicago, who led the study. “It represents a paradigm shift in our understanding of how genes ultimately encode proteins.”
The study was published last week in “Cell.” Read more about it in our Newsroom.
Du X., Wang J., Zhu H., Rinaldo L., Lamar K.M., Palmenberg A., Hansel C. & Gomez C. (2013). Second Cistron in CACNA1A Gene Encodes a Transcription Factor Mediating Cerebellar Development and SCA6, Cell, 154 (1) 118-133. DOI: 10.1016/j.cell.2013.05.059