NE-CAT News

Restoring the tumor suppressive activity of the Hippo signaling pathway lost through dysregulation of the NUAK1/2 and MARK2/3 kinase axis and downstream transcriptional effectors YAP/TAZ has emerged as a new modality for the treatment of several human cancers. Small molecule inhibition of NUAK1/2 and MARK2/3 constitutes a rational approach to block YAP/TAZ nuclear translocation and prevent a pro-oncogenic gene expression program. Modest structural changes to lead compound OICR14489, discovered...

Aspartate transcarbamoylase (ATCase) from Escherichia coli catalyzes a key step in pyrimidine nucleotide biosynthesis and has long served as a model for allosteric regulation. Despite decades of study, how nucleotide binding at distant regulatory sites controls cooperativity between active sites remained unresolved. Here we show that ATCase does not simply interconvert between two conformations, as traditionally depicted, but instead samples a continuum of conformations that tune enzyme...

Cellular metabolites have emerged as noncanonical RNA caps. Despite its early discovery as an RNA cap, the dephospho-CoA (dpCoA) cap remains largely uncharacterized because of a lack of detection technologies. Here we use biochemical and structural analysis to identify Arabidopsis NUDT11 as a specific decapping enzyme toward dpCoA-RNA. Leveraging this specificity, we develop biochemical and transcriptomic methods to quantify and profile dpCoA-RNA across the genome, revealing that dpCoA-RNAs...

Bacteria encode myriad stress-response pathways that protect their hosts against both internal and external threats. A key question is how these pathways are regulated, especially anti-phage immune pathways that mediate host cell killing. Here, we identify two proteins termed CapK and CapS that are encoded upstream of diverse immune operons, and regulate their expression in response to DNA damage. CapK resembles bacterial anti-sigma factor kinases, and CapS resembles these proteins' STAS domain...

The clinically significant pathogen Clostridioides difficile lacks the transmembrane nutrient germinant receptors conserved in almost all spore-forming bacteria. Instead, C. difficile initiates spore germination using a unique mechanism that requires two signals: a bile acid germinant and a co-germinant, which can be either an amino acid or a divalent cation. While two soluble pseudoproteases, CspC and CspA, were initially identified as the germinant and co-germinant receptors, respectively, in...

RAF activation is essential for MAPK signaling and is mediated by RAS binding and the dephosphorylation of a conserved phosphoserine by the SHOC2-RAS-PP1C complex. MRAS forms a high-affinity SHOC2-MRAS-PP1C (SMP) complex, while canonical RAS isoforms (KRAS, HRAS, NRAS) form analogous but lower-affinity assemblies. Yet, cancers driven by oncogenic KRAS, HRAS, or NRAS remain strongly SHOC2-dependent, suggesting that these weaker complexes contribute to tumorigenesis. To elucidate how canonical RAS...

Kinesin motors use ATP to produce force in cells, yet the conformational changes that generate force remain uncertain. Here, we report structural and mechanistic insights into a minus-end-directed kinesin-14 that exhibits increased mechanical output – the variant motor binds microtubules more tightly and moves with faster velocity than wild type. High-resolution structures, together with molecular dynamics simulations, reveal previously unobserved transitions in the nucleotide hydrolysis cycle....

Cryptochromes (CRYs) play critical roles in regulating diverse physiological functions, including circadian rhythms and neuronal firing in light-dependent or -independent fashions. Structural studies of CRYs have highlighted common features, such as the photolyase homology region (PHR), but they also reveal key differences, particularly in the binding of the flavin adenine dinucleotide (FAD) cofactor, leading to a long-standing debate, namely, whether Type I CRYs can function as FAD-dependent...

The endogenously expressed BET proteins (BRD2, BRD3, BRD4) are upstream clinical targets for anti-inflammatory treatments, where inhibition of the tandem bromodomains (D1 and D2) have proven efficacious in vitro and in vivo towards NF-κB-mediated inflammation. Despite their efficacy, dose-limiting toxicities associated with BET inhibition have limited clinical progression. One strategy to circumvent these dose-limiting toxicities has included domain- or protein-selective inhibition of the BET...

Small molecule binding within internal cavities provides a way to control protein function and structure, as exhibited in numerous natural and artificial settings. Unfortunately, most ways to identify suitable cavities require high-resolution structures a priori and may miss potential sites. Here we address this limitation via high-pressure solution NMR spectroscopy, taking advantage of the distinctive nonlinear pressure-induced chemical shift changes observed in proteins containing internal...