WDR77 inhibits prion-like aggregation of MAVS to limit antiviral innate immune response

Abstract RIG-I-MAVS signaling pathway plays a crucial role in defending against pathogen infection and maintaining immune balance. Upon detecting viral RNA, RIG-I triggers the formation of prion-like aggregates of the adaptor protein MAVS, which then activates the innate antiviral immune response. However, the mechanisms that regulate the aggregation of MAVS are not yet fully understood. Here, we identified WDR77 as a MAVS-associated protein, which negatively regulates MAVS aggregation. WDR77 binds to MAVS proline-rich region through its WD2-WD3-WD4 domain and inhibits the formation of prion-like filament of recombinant MAVS in vitro. In response to virus infection, WDR77 is recruited to MAVS to prevent the formation of its prion-like aggregates and thus downregulate RIG-I-MAVS signaling in cells. WDR77 deficiency significantly potentiates the induction of antiviral genes upon negative-strand RNA virus infections, and myeloid-specific Wdr77-deficient mice are more resistant to RNA virus infection. Our findings reveal that WDR77 acts as a negative regulator of the RIG-I-MAVS signaling pathway by inhibiting the prion-like aggregation of MAVS to prevent harmful inflammation

Surges in volcanic activity on the Moon about two billion years ago

Abstract The history of mare volcanism critically informs the thermal evolution of the Moon. However, young volcanic eruptions are poorly constrained by remote observations and limited samples, hindering an understanding of mare eruption flux over time. The Chang’e-5 mission returned the youngest lunar basalts thus far, offering a window into the Moon’s late-stage evolution. Here, we investigate the mineralogy and geochemistry of 42 olivine and pyroxene crystals from the Chang’e-5 basalts. We find that almost all of them are normally zoned, suggesting limited magma recharge or shallow-level assimilation. Most olivine grains record a short timescale of cooling. Thermal modeling used to estimate the thickness and volume of the volcanism sampled by Chang’e-5 reveals enhanced magmatic flux ~2 billion years ago, suggesting that while overall lunar volcanic activity may decrease over time, episodic eruptions at the final stage could exhibit above average eruptive fluxes, thus revising models of lunar thermal evolution

High abundance of solar wind-derived water in lunar soils from the middle latitude

International audienceThe latitude-dependent and probably time-of-day variations of water (OH/H2O) on the Moon surface have previously been explored by reflectance spectroscopy. The lunar soils returned by the Chang'e-5 mission from a middle latitude, significantly higher than Apollo missions, provide a unique opportunity for studying the latitude-dependent implantation and retention of solar wind (SW)-derived water in lunar soils. We have conducted a combined NanoSIMS-FIB-TEM analysis of the CE-5 soil grains, complemented by the heating experiments. The high abundance of SW-derived hydrogen in the rims of the grains provides a significant constraint on the preservation of SW-derived water in lunar soils. The predicted water contents of bulk soils in the lunar polar regions are consistent with the remote sensing data