David Bartel

This past year, we’ve had an exciting breakthrough in our understanding of gene regulation. 

We study microRNAs: small RNA molecules that work with a protein partner to destroy messenger RNAs, the genetic instructions cells use to make proteins. These microRNAs regulate most human genes. But a question we’ve been exploring has been: how are microRNAs themselves regulated?

We’ve discovered how another type of RNA, called a trigger RNA, initiates the process that breaks down microRNAs. When a microRNA complex attaches to a trigger RNA, a protein called ZSWIM8 becomes able to bind to the complex, marking it for degradation.

For this system to work, ZSWIM8 must be extremely selective, and act only when a trigger RNA is present. Working together with collaborators in Brenda Schulman’s lab, we’ve been able to examine the detailed structure of the protein–RNA complex and learn how that structure enables such selective control.