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cGAS‐STING signalling is induced by detection of foreign or mislocalised host double‐stranded (ds)DNA within the cytosol. STING acts as the major signalling hub, where it controls production of type I interferons and inflammatory cytokines. Basally, STING resides on the ER membrane. Following activation STING traffics to the Golgi to initiate downstream signalling and subsequently to endolysosomal compartments for degradation and termination of signalling. While STING is known to be degraded within lysosomes, the mechanisms controlling its delivery remain poorly defined. Here we utilised a proteomics‐based approach to assess phosphorylation changes in primary murine macrophages following STING activation. This identified numerous phosphorylation events in proteins involved in intracellular and vesicular transport. We utilised high‐temporal microscopy to track STING vesicular transport in live macrophages. We subsequently identified that the endosomal complexes required for transport (ESCRT) pathway detects ubiquitinated STING on vesicles, which facilitates the degradation of STING in murine macrophages. Disruption of ESCRT functionality greatly enhanced STING signalling and cytokine production, thus characterising a mechanism controlling effective termination of STING signalling. Synopsis: Effective termination of STING signalling is crucial to prevent unwarranted inflammation. Utilising biochemical and microscopy approaches, here we identify that the ESCRT pathway facilitates STING degradation and shuts off immune signalling. STING activation induces phosphorylation changes in a large number of intracellular trafficking proteins.Ubiquitination of STING is essential for its degradation.The ESCRT pathway mediates the termination of STING responses. [ABSTRACT FROM AUTHOR]

The mass spectra of twenty-seven C-19 modified cholestane derivatives have been determined, and have been compared with the mass spectra of similar compounds reported1 in the cholesteryl series. In the spectra of 2α,19-dihydroxy-5α-cholestane (la), initial loss of the 10β-hydroxymethyl group was observed followed by loss of water, whereas with the 2α-methoxy and 2α-acetoxy derivatives (Ib, Ic), loss of the 2α-substituent as methanol and acetic acid respectively, preceded the elimination of the 10β-hydroxymethyl group. Loss of the 10β-hydroxymethyl group was also observed in Δ1-, Δ2- and 2-oxo derivatives (VI, Va and VII), whilst loss of both the 1 substituent and the 10β-hydroxymethyl group from the molecular ion was observed with the 1α-ol (IIa) and the 1β-yl-chloride (III). In a series of 19-acetoxy derivatives loss of acetic acid [M - 60] from the 19-acetoxy group, involving abstraction of a sterically favourable hydrogen, always occurred, although this was usually accompanied by loss of the 10β-acetoxymethyl residue [M - 73]. The mass spectra of a series of 10β-carboxylic acids and their methyl esters were more complex with three or more fragmentation patterns being observed. 1,3-Diaxial interactions, similar to those observed in chemical reactions, were observed in the mass spectra of three 2β-oxygenated-19-substituted compounds. [ABSTRACT FROM AUTHOR]