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Abstract Salicylic acid (SA) production in Brassicaceae plants is uniquely accelerated from isochorismate by EPS1, a newly identified enzyme in the BAHD acyltransferase family. We present crystal structures of EPS1 from Arabidopsis thaliana in both its apo and substrate-analog-bound forms. Integrating microsecond-scale molecular dynamics simulations with quantum mechanical cluster modeling, we propose a pericyclic rearrangement lyase mechanism for EPS1. We further reconstitute the isochorismate-derived SA biosynthesis pathway in Saccharomyces cerevisiae, establishing an in vivo platform to examine the impact of active-site residues on EPS1 functionality. Moreover, stable transgenic expression of EPS1 in soybean increases basal SA levels, highlighting the enzyme’s potential to enhance defense mechanisms in non-Brassicaceae plants lacking an EPS1 ortholog. Our findings illustrate the evolutionary adaptation of an ancestral enzyme’s active site to enable a novel catalytic mechanism that boosts SA production in Brassicaceae plants.

Abstract In pancreatic ductal adenocarcinoma (PDAC), endogenous MYC is required for S-phase progression and escape from immune surveillance. Here we show that MYC in PDAC cells is needed for the recruitment of the PAF1c transcription elongation complex to RNA polymerase and that depletion of CTR9, a PAF1c subunit, enables long-term survival of PDAC-bearing mice. PAF1c is largely dispensable for normal proliferation and regulation of MYC target genes. Instead, PAF1c limits DNA damage associated with S-phase progression by being essential for the expression of long genes involved in replication and DNA repair. Surprisingly, the survival benefit conferred by CTR9 depletion is not due to DNA damage, but to T-cell activation and restoration of immune surveillance. This is because CTR9 depletion releases RNA polymerase and elongation factors from the body of long genes and promotes the transcription of short genes, including MHC class I genes. The data argue that functionally distinct gene sets compete for elongation factors and directly link MYC-driven S-phase progression to tumor immune evasion.

The ferromagnetic phase of Co3Sn2S2 is widely considered to be a topological Weyl semimetal, with evidence for momentum-space monopoles of Berry curvature from transport and spectroscopic probes. As the bandstructure is highly sensitive to the magnetic order, attention has focused on anomalies in magnetization, susceptibility and transport measurements that are seen well below the Curie temperature, leading to speculation that a "hidden" phase coexists with ferromagnetism. Here we report spatially-resolved measurements by Kerr effect microscopy that identify this phase. We find that the anomalies coincide with a deep minimum in domain wall (DW) mobility, indicating a crossover between two regimes of DW propagation. We demonstrate that this crossover is a manifestation of a 2D phase transition that occurs within the DW, in which the magnetization texture changes from continuous rotation to unidirectional variation. We propose that the existence of this 2D transition deep within the ferromagnetic state of the bulk is a consequence of a giant quality factor for magnetocrystalline anisotropy unique to this compound. This work broadens the horizon of the conventional binary classification of DWs into Bloch and Néel walls, and suggests new strategies for manipulation of domain walls and their role in electron and spin transport.

Abstract Global agricultural trade creates multiple telecoupled flows of nitrogen (N) and phosphorus (P). The flows of physical and virtual nutrients along with trade have discrepant effects on natural resources in different countries. However, existing literature has not quantified or analyzed such effects yet. Here we quantified the physical and virtual N and P flows embedded in the global agricultural trade networks from 1997 to 2016 and elaborated components of the telecoupling framework. The N and P flows both increased continuously and more than 25% of global consumption of nutrients in agricultural products were related to physical nutrient flows, while virtual nutrient flows were equivalent to one-third of the nutrients inputs into global agricultural system. These flows have positive telecoupling effects on saving N and P resources at the global scale. Reducing inefficient trade flows will enhance resource conservation, environmental sustainability in the hyper-globalized world.

Plant biosynthetic enzymes rapidly evolve to catalyze specialized reactions. Here, the authors present the crystal structure and mechanism of COSY, the enzyme involved in coumarin biosynthesis of the BAHD-acyltransferase family that catalyzes an intramolecular acyl transfer reaction through a proton exchange mechanism.

In the Bloch or Neel domain walls in ferromagnets, the magnetization rotates smoothly from up to down, preserving its magnitude. Here, Lee et al show that Co3Sn2S2 exhibits a phase transition within its domain walls to a state in which the magnetization passes through zero rather than rotating as the wall is traversed.

Land use is a major driver of biodiversity loss, but disentangling the contribution of its various components is challenging. Here, the authors partition the role of land use type and intensity in explaining global patterns of impending species losses for terrestrial vertebrates.

Measuring the ever-changing 3-dimensional (3D) motions of the ocean requires simultaneous sampling at multiple locations. In particular, sampling the complex, nonlinear dynamics associated with submesoscales (

Recent evidence shows that spatial attention is discontinuous over time, sampling locations in rhythmic cycles (3–6 Hz). Here, the authors show that the pulvinar has a role in coordinating this rhythmic sampling, with neural activity propagating from pulvinar to cortex during periods of engagement.

The pulvinar is involved in vision and attention, but its interactions with other brain regions are little-studied. Here, using fMRI the authors show that the human pulvinar has widespread functional coupling with cortical areas that reflects its intrinsic organization and the topographic layout of cortex.

Observing dynamics associated with oceanic submesoscales requires simultaneous sampling at multiple locations. Here, the authors show that a swarm of 16 Mini-Autonomous Underwater Explorers (M-AUEs), whose 3D trajectories are measured near-continuously, can resolve features of the flow at these scales.

The assembly of the splicesome involves several distinct stages that require the sequential action of DExD/H-box RNA helicases. Here, the authors uncover a new intermediate, the pre-B complex, that accumulates in the presence of an inactive form of the DEAD-box protein Prp28.

Safeguarding existing forests is an important ecological concern but constrains the expansion of farmland to feed the growing world population. Here the authors analyse the option space for future changes in agriculture and diets compatible with a no-deforestation goal.

The original version of this Article contained an error in the author affiliations. Affiliation 3 incorrectly read ‘Department of Biological and Brain Sciences, Johns Hopkins University, Baltimore, MD 21218, USA’.

T-cell development is accompanied by epigenetic changes that ensure the silencing of stem cell-related genes and the activation of lymphocyte-specific programmes. How transcription factors influence these changes remains unclear. We show that the Ikaros transcription factor forms a complex with Polycomb repressive complex 2 (PRC2) in CD4(-)CD8(-) thymocytes and allows its binding to more than 500 developmentally regulated loci, including those normally activated in haematopoietic stem cells and others induced by the Notch pathway. Loss of Ikaros in CD4(-)CD8(-) cells leads to reduced histone H3 lysine 27 trimethylation and ectopic gene expression. Furthermore, Ikaros binding triggers PRC2 recruitment and Ikaros interacts with PRC2 independently of the nucleosome remodelling and deacetylation complex. Our results identify Ikaros as a fundamental regulator of PRC2 function in developing T cells.