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The data obtained from the experiments and scripts used for analyses can be found in the data repository of CIRAD Dataverse (https://doi.org/10.18167/DVN1/D3OP8O).; International audience; Highlights:• We hypothesize that attraction to fresh faeces enhance locust hopper band cohesion.• We exposed third instar hoppers of desert locust to faeces odours of different ages.• We observed an attraction of faeces explained by 11 volatile organic compounds.• Latecomers could get back to the band following faeces’ odours after 24 h.Abstract:Collective motion is one of the most impressive common features of gregarious locusts: once formed, bands and swarms get moving for long distances. It was shown that visual perception of neighbours plays a key role in maintaining marching behaviour at a local scale. But at a larger scale, mechanisms underlying band cohesion are less understood. It was shown in several field studies that individuals separated from the band were able to get back to the group, even after being separated since a night. In this context, faeces’ odours could be a possible indicator of the recent passage of a group. In this study, we tested if nymphs are attracted by faeces’ odours and if this effect is modulated by the age of the faeces. To this end, we conducted individual olfactometric behavioural assays of instar hoppers of desert locust, Schistocerca gregaria, exposed to odours of 1 h-old and 24 h-old faeces. We also used Gas Chromatography-Mass Spectrometry (GC–MS) to identify odours’ volatile organic compounds from faeces. The results of behavioural assays indicated a strong attractive effect of faeces, with no preference for one of the two faecal age classes. Nymphs spent significantly more time in the side of the olfactometer where the faeces’ odours came from, and 72.7% of tested individuals chose this side first. We filtered and annotated 11 volatile organic compounds present in both fresh and old faeces in GC–MS analyses, including guaiacol and phenol, which are known to cause an aggregative effect on desert locusts. As the attractive effect lasted over 24 h, band’s faeces could still have an attractive effect when individuals are separated from the band since one day. In this situation, latecomers individuals would be able to get back to the group by following the traces of their predecessors.

PPM1D encodes a serine/threonine phosphatase that regulates numerous pathways including the DNA damage response and p53. Activating mutations and amplification of PPM1D are found across numerous cancer types. GSK2830371 is a potent and selective allosteric inhibitor of PPM1D, but its mechanism of binding and inhibition of catalytic activity are unknown. Here we use computational, biochemical and functional genetic studies to elucidate the molecular basis of GSK2830371 activity. These data confirm that GSK2830371 binds an allosteric site of PPM1D with high affinity. By further incorporating data from hydrogen deuterium exchange mass spectrometry and sedimentation velocity analytical ultracentrifugation, we demonstrate that PPM1D exists in an equilibrium between two conformations that are defined by the movement of the flap domain, which is required for substrate recognition. A hinge region was identified that is critical for switching between the two conformations and was directly implicated in the high-affinity binding of GSK2830371 to PPM1D. We propose that the two conformations represent active and inactive forms of the protein reflected by the position of the flap, and that binding of GSK2830371 shifts the equilibrium to the inactive form. Finally, we found that C-terminal truncating mutations proximal to residue 400 result in destabilization of the protein via loss of a stabilizing N- and C-terminal interaction, consistent with the observation from human genetic data that nearly all PPM1D mutations in cancer are truncating and occur distal to residue 400. Taken together, our findings elucidate the mechanism by which binding of a small molecule to an allosteric site of PPM1D inhibits its activity and provides insights into the biology of PPM1D.