Institutional development · Research, innovation and assessment · Japan
Kyoto-led team finds rotating helix triggers GDP release in Gα proteins
Researchers from Kyoto, Tohoku and Tokyo universities report in Nature Chemical Biology that a rotating helix in the Gα protein starts the release of GDP, a key step in cell signalling.
Why it matters: Researchers studying GPCR-targeted medicines gain a newly described mechanism for how the G protein switch is turned on.
Kyoto University said a research group found that the N-terminal helix of the Gα protein rotates in a particular direction, passing a structural change to the GDP binding site and triggering GDP (guanosine diphosphate) release.
The group included Kyoto University doctoral student Daiki Arai and Professor Asuka Inoue, who also holds a professorship at Tohoku University, plus University of Tokyo professors Osamu Nureki and Yuji Sasaki.
The findings appeared in Nature Chemical Biology on 30 October 2026, and the university said they are expected to underpin a more detailed understanding of drugs targeting GPCRs (G protein-coupled receptors).
Professor Inoue said co-author Professor Roger Sunahara had proposed about ten years ago that the N-terminal helix might be involved in GDP release.
Editor’s view
Scott James, Research and Innovation Editor
For researchers working on GPCR-targeted medicines, the reported mechanism offers a basis for more detailed study of drug action, according to Kyoto University; the study was published on 30 October 2026.
