Cryo-electron microscopy sheds light on endothelin signaling mechanisms

Endothelin is a peptide hormone known for its vasoconstrictive effects. Researchers at University of Tsukuba used cryo-electron microscopy to examine the complex structure of the endothelin receptor and G protein, which are crucial for signal transduction at the cell membrane. This study has clarified the mechanism of signal transduction between cells.

The human body is composed of approximately 60 trillion cells, which rely on the coordinated exchange of information to maintain normal biological functions. Each cell is surrounded by a membrane that facilitates the transmission of external signals into the cell through receptor proteins.

Despite the clear elucidation of the binding structure of endothelin (ET), a vasoconstrictive peptide hormone, to the endothelin B-type receptor (ET_BR) on the plasma membrane, the detailed structure of the ET_BR-G protein complex—essential for signal transmission on the membrane—remains unclear. Additionally, the precise mechanism of signal transduction is not yet fully understood.

In a study, published in Communications Biology, researchers utilized cryo-electron microscopy to observe the complex structure of ET, ET_BR, and G protein.

A strong binding interaction was revealed between the G protein and ET_BR. The study also offered valuable insights into the mechanisms that distinguish types of G proteins and the factors that activate the receptor.

These findings may deepen our understanding of endothelin signaling mechanisms and have practical implications for the development of new drugs based on these structural properties.