The Chinese research group Nature issued a document: the first time to provide an accurate image of the activation state of STING

Dr.

Near-atomic-resolution imaging of a key immune protein called STING has revealed a previously unrecognized binding site that appears to be is the key to launching an immune attack

"This work provides, for the first time, a precise picture of the activation state of STING, which is critical for understanding its role in normal immunity and autoimmune disease," said study author Dr.

 Dr.

STING, short for "interferon gene stimulator," is a core part of the innate immune system and the body's first line of defense against viruses, bacteria, and cancer

In collaboration with Zhijian Chen, Ph.

The synthetic drug-like compound (magenta sphere at the bottom) targets a hidden pocket in STING

While this work elucidates some of the fundamental mechanisms that govern STING activity, exactly how this protein is converted into its active form is unclear

To increase the amount of activated STING available for imaging, the scientists added an investigational drug called compound 53 (C53), which is currently being tested as a STING activator in anticancer therapy

Binding of cGAMP and C53 produced more activated STING molecules

"This newly discovered STING-activated binding site was completely unexpected, and we called it the 'mystery pocket' because it appears to have formed in response to the presence of C53

The fact that STING appears to be required to activate both cGAMP and C53 suggests that an unknown molecule similar to C53 may exist in cells to play the same role, Dr.

One day, drugs that attach to or block this newly discovered binding site could be used to boost or weaken the immune system to fight infectious or autoimmune diseases, the researchers added