Design, Synthesis, and Structure−Activity Relationship Exploration of 1-Substituted 4-Aroyl-3-hydroxy-5-phenyl-1H-pyrrol-2(5H)-one Analogues as Inhibitors of the Annexin A2−S100A10 Protein Interaction

This research was supported by grants from Cancer Research UK. H.K.M. was funded by a Biotechnology and Biological Sciences Research Council studentship.S100 proteins are small adaptors that regulate the activity of partner proteins by virtue of direct protein interactions. Here, we describe the first small molecule blockers of the interaction between S100A10 and annexin A2. Molecular docking yielded candidate blockers that were screened for competition of the binding of an annexin A2 peptide to S100A10. Several inhibitory clusters were identified with some containing compounds with potency in the lower micromolar range. We chose 3-hydroxy-1-(2-hydroxypropyl)-5-(4-isopropylphenyl)-4-(4-methylbenzoyl)-1H-pyrrol-2(5H)-one (1a) as a starting point for structure-activity studies. These confirmed the hypothetical binding mode from the virtual screen for this series of molecules. Selected compounds disrupted the physiological complex of annexin A2 and S100A10, both in a broken cell preparation and inside MDA-MB-231 breast cancer cells. Thus, this class of compounds has promising properties as inhibitors of the interaction between annexin A2 and S100A10 and may help to elucidate the cellular function of this protein interaction.Peer reviewe

The human protein HSPC021 interacts with Int-6 and is associated with the translation initiation factor eIF3.

International audienc

S100 protein-annexin interactions:a model of the (Anx2-p11)(2) heterotetramer complex

AbstractThe (Anx2)2(p11)2 heterotetramer has been implicated in endo- and exocytosis in vivo and in liposome aggregation in vitro. Here we report on the modelling of the heterotetramer complex using docking algorithms. Two types of models are generated–heterotetramer and heterooctamer. On the basis of the agreement between the calculated (X-ray) electron density and the observed projected density from cryo-electron micrographs on the one hand, and calculated energy criteria on the other hand, the heterotetramer models are proposed as the most probable, and one of them is selected as the best model. Analysis of this model at an atomic level suggests that the interaction between the Anx2 core and p11 has an electrostatic character, being stabilised primarily through charged residues

Magnetic resonance imaging of skeletal muscle involvement in limb restricted vasculitis

Objective: To describe the MRI findings in the legs of three patients with limb restricted vasculitides (two PAN, one isolated vasculitis of the skeletal muscle) with histologically established muscle involvement. Methods: MRI was carried out on calf muscles and T(2) weighted images, unenhanced T(1) weighted images, and STIR sequences were obtained. Results: Muscle damage resulted in oedema-like changes on MRI characterised by hyperintense signals in T(2) weighted and slow tau inversion recovery (STIR) sequences and normal unenhanced T(1) weighted sequences of one or several leg muscles. Conclusions: MRI should be considered a useful complementary examination that might facilitate the recognition of limb restricted vasculitides, and possibly indicate the site for muscle biopsy. It could also be useful in monitoring the course of the disease. Future studies should also evaluate MRI for systemic PAN or other systemic vasculitides with muscle involvement

Acute hypertensive encephalopathy with widespread small-vessel disease at MRI in a diabetic patient: pathogenetic hypotheses

articleWe report unusual magnetic resonance imaging (MRI) findings in a diabetic patient with neglected hypertension and hyperglycemia, presenting with seizures and coma. Outcome was fatal despite intensive care. The MRI findings included bilateral insular and temporo-occipital grey and white matter involvement, and numerous, scattered, lacunar-like lesions involving the peripheral and deep white matter, basal ganglia grey matter, and brainstem. Lesions had a low apparent diffusion coefficient, and some enhanced following contrast injection. Hypertensive encephalopathy with widespread and severe acute small-vessel disease was considered. Pathophysiology is discussed

Identification of Regions Responsible for the Open Conformation of S100A10 Using Chimaeric S100A11-S100A10 Proteins

S100A11 is a dimeric EF-hand calcium-binding protein. Calcium binding to S100A11 results in a large conformational change that uncovers a broad hydrophobic surface used to interact with phospholipid-binding proteins (annexins A1 and A2) and facilitate membrane vesiculation events. In contrast with other S100 proteins, S100A10 is unable to bind calcium due to deletion and substitution of calcium-ligating residues. Despite this, calcium-free S100A10 assumes an \u27open\u27 conformation that is very similar to S100A11 in its calcium-bound state. To understand how S100A10 is able to adopt an open conformation in the absence of calcium, seven chimaeric proteins were constructed where regions from calcium-binding sites I and II, and helices II-IV in S100A11 were replaced with the corresponding regions of S100A10. The chimaeric proteins having substitutions in calcium-binding site II displayed increased hydrophobic surface exposure as assessed by bis-ANS (4,4\u27-dianilino-1,1\u27-binaphthyl-5,5\u27disulfonic acid, dipotassium salt) fluorescence and phenyl-Sepharose binding in the absence of calcium. This response is similar to that observed for Ca2+-S100A11 and calcium-free S100A10. Further, this substitution resulted in calcium-insensitive binding to annexin A2 for one chimaeric protein. The results indicate that residues within site II are important in stabilizing the open conformation of S100A10 and presentation of its target binding site. In contrast, S100A11 chimaeric proteins with helical substitutions displayed poorer hydrophobic surface exposure and, consequently, unobservable annexin A2 binding. The present study represents a first attempt to systematically understand the molecular basis for the calcium-insensitive open conformation of S100A10

Authoring Issues beyond Tools

Abstract. Authoring is still considered a bottleneck in successful Interactive Storytelling and Drama. The claim for intuitive authoring tools is high, especially for tools that allow storytellers and artists to define dynamic content that can be run with an AI-based story engine. We explored two concrete authoring processes in depth, using various Interactive Storytelling prototypes, and have provided feedback from the practical steps. The result is a presentation of general issues in authoring Interactive Storytelling, rather than of particular problems with a specific system that could be overcome by ‘simply ’ designing the right interface. Priorities for future developments are also outlined

Scent evolution in Chinese roses

The phenolic methyl ether 3,5-dimethoxytoluene (DMT) is a major scent compound of many modern rose varieties, and its fragrance participates in the characteristic “tea scent” that gave their name to Tea and Hybrid Tea roses. Among wild roses, phenolic methyl ether (PME) biosynthesis is restricted to Chinese rose species, but the progenitors of modern roses included both European and Chinese species (e.g., Rosa chinensis cv Old Blush), so this trait was transmitted to their hybrid progeny. The last steps of the biosynthetic pathways leading to DMT involve two methylation reactions catalyzed by the highly similar orcinol O-methyltransferases (OOMT) 1 and 2. OOMT1 and OOMT2 enzymes exhibit different substrate specificities that are consistent with their operating sequentially in DMT biosynthesis. Here, we show that these different substrate specificities are mostly due to a single amino acid polymorphism in the phenolic substrate binding site of OOMTs. An analysis of the OOMT gene family in 18 species representing the diversity of the genus Rosa indicated that only Chinese roses possess both the OOMT2 and the OOMT1 genes. In addition, we provide evidence that the Chinese-rose-specific OOMT1 genes most probably evolved from an OOMT2-like gene that has homologues in the genomes of all extant roses. We propose that the emergence of the OOMT1 gene may have been a critical step in the evolution of scent production in Chinese roses