RU.521 (RU320521) is a potent and selective inhibitor of cyclic GMP-AMP synthase (cGAS) that suppresses the chronically elevated levels of type I interferon in primary macrophages from Trex1 null mice. Ru.521 binds to the CGAS catalytic pocket and inhibits dsDNA-induced cGAS-mediated interferon upregulation.
RU.521 helps to understand the biological functions of cyclic guanosine monophosphate-adenosine monophosphate (cyclic GMP-AMP) synthase. It can act as a molecular scaffold for developing future autoimmune therapies. RU.521 can also inhibit the inflammatory cytokine expression induced by Aspergillus fumigatus.