Form and Function The contribution of disulfide bonding to oxidative protein folding assembly, quality control, stress responses in the endoplasmic reticulum (ER) are widely recognized. In contrast, catalysis bond formation downstream ER is uncharted territory. QSOX, a Golgi-localized or secreted catalyst, was identified 1970s more recently shown be upregulated many cancers. However, physiological importance QSOX catalytic activity has been unclear. Ilani et al. (p. 74 , published online 23...

The respiratory and intestinal tracts are exposed to physical biological hazards accompanying the intake of air food. Likewise, vasculature is threatened by inflammation trauma. Mucin glycoproteins related von Willebrand factor guard vulnerable cell layers in these diverse systems. Colon mucins additionally house feed gut microbiome. Here, we present an integrated structural analysis mucin MUC2. Our findings reveal shared mechanism which complex macromolecules responsible for blood clotting,...

The entry of calcium into mitochondria is central to metabolism, inter-organelle communication, and cell life/death decisions. Long-sought transporters involved in mitochondrial influx efflux have recently been identified. To obtain a unified picture utilization, parallel advance understanding the forms quantities stores needed. We present here direct 3D visualization intact mammalian cells using cryo-scanning transmission electron tomography (CSTET). Amorphous solid granules containing...

Dopamine is a major neurotransmitter in the central nervous system, and its receptors are associated with number of neuropathological disorders such as Parkinson's disease schizophrenia. Although precise pathophysiology schizophrenia remains unknown, dopaminergic hypothesis illness assumes that results from excessive activity at dopamine synapses brain. Because, present, diagnosis relies on descriptive behavioral symptomatic information, peripheral measurable marker may enable simpler, more...

Mucus protects the epithelial cells of digestive and respiratory tracts from pathogens other hazards. Progress in determining molecular mechanisms mucus barrier function has been limited by lack high-resolution structural information on mucins, giant, secreted, gel-forming glycoproteins that are major constituents mucus. Here, we report how mucin structures determined enabled discovery an unanticipated protective role mucus: managing toxic transition metal copper. Using two juxtaposed copper...

Immunological synapse (IS) formation involves receptor–ligand pair clustering and intracellular signaling molecule recruitment with a coincident removal of other membrane proteins away from the IS. As microfilament–membrane linkage is critical to this process, we investigated involvement ezrin moesin, two ezrin/radixin/moesin expressed in T cells. We demonstrate that which are generally believed be functionally redundant, differentially localized have important complementary functions IS...

Neuro-immune interactions enable mutual regulation of the nervous and immune systems. To date, evidence exists for manipulations cells by neurotransmitters in periphery. In this study, we suggest existence a pathway which brain affects cells. The describe here is mediated dopamine receptors expressed on activated T cells, termed blasts. Blasts can cross blood barrier regardless antigen specificity therefore encounter brain. We show that blasts have unique response to dopaminergic activation,...

Mucus is made of enormous mucin glycoproteins that polymerize by disulfide crosslinking in the Golgi apparatus. QSOX1 a catalyst bond formation localized to Golgi. Both and mucins are highly expressed goblet cells mucosal tissues, leading hypothesis catalyzes disulfide-mediated polymerization. We found knockout mice lacking had impaired mucus barrier function due production defective mucus. However, an investigation on molecular level revealed normal polymerization related glycoproteins....

The design and function of a synthetic "chemical transducer" that can generate an unnatural communication channel between two proteins is described. Specifically, we show how this transducer enables platelet-derived growth factor to trigger (in vitro) the catalytic activity glutathione-s-transferase (GST), which not its natural enzyme partner. GST be further controlled by adding specific oligonucleotides switch enzymatic reaction on off. We also demonstrate molecular machine, regulate...

The selective and sensitive identification of different proteins becomes possible by modifying the known intercalating dye, thiazole orange, with two protein binders. These ‘turn-on’ fluorescence probes enable acetylcholinesterase, glutathione-<italic>s</italic>-transferases avidin high affinity, specificity, signal-to-noise ratio.

The mucin 2 glycoprotein assembles into a complex hydrogel that protects intestinal epithelia and houses the gut microbiome. A major step in assembly is further multimerization of preformed dimers, thought to produce honeycomb-like arrangement upon expansion. Important open questions are how multiple dimers become covalently linked one another compares with analogous processes related polymers such as respiratory tract mucins hemostasis protein von Willebrand factor. Here we report x-ray...

Recent studies have suggested that the alpha7 nicotinic acetylcholine receptor (alpha7 AChR) may play a role in pathogenesis of schizophrenia. In search for peripheral biological markers schizophrenia we investigated mRNA levels blood lymphocytes (PBLs) schizophrenic patients and healthy controls. Peripheral samples were collected from medicated non-medicated (drug naive) as well (non-mentally ill) smokers non-smokers. RNA was prepared isolated lymphocytes. Polymerase chain reaction products...

Abstract Lymphocyte arrest and spreading on ICAM-1–expressing APCs require activation of lymphocyte LFA-1 by TCR signals, but the conformational switches this integrin during these critical processes are still elusive. Using Ab probes that distinguish between different conformations, we found that, unlike strong chemokine potent stimuli were insufficient to trigger extension or headpiece opening in primary human lymphocytes. Nevertheless, TCR-stimulated T cells became highly adhesive both...

Extracellular matrix (ECM) plays an important role in tumor development and dissemination, but few points of therapeutic intervention targeting ECM the microenvironment have been exploited to date. Recent observations suggest that enzymatic introduction disulfide bond cross-links into may be modulated affect cancer progression. Specifically, bond-forming activity enzyme Quiescin sulfhydryl oxidase 1 (QSOX1) is required by fibroblasts assemble components for adhesion migration cells. Based on...

Cells and extracellular matrix (ECM) are mutually interdependent: cells guide self-assembly of ECM precursors, the resulting architecture supports instructs cells.Though bidirectional signaling between is fundamental to cell biology, it challenging gain high-resolution structural information on cellular responses microenvironment.Here we used cryo-scanning transmission electron tomography (CSTET) reveal nanometer-to micron-scale organization major fibroblast components in a nativelike...

The secreted disulfide catalyst Quiescin sulfhydryl oxidase-1 (QSOX1) affects extracellular matrix organization and is overexpressed in various adenocarcinomas associated stroma. Inhibition of human QSOX1 by a monoclonal antibody decreased tumor cell migration co-culture model hence may have therapeutic potential. However, the species specificity has been setback assessing its utility as an anti-metastatic agent vivo, common problem therapy industry. We therefore used structurally guided...

Quiescin sulfhydryl oxidase 1 (QSOX1) catalyzes the formation of disulfide bonds in protein substrates. Unlike other enzymes with related activities, which are commonly found endoplasmic reticulum, QSOX1 is localized to Golgi apparatus or secreted. upregulated quiescent fibroblast cells and secreted into extracellular environment, where it contributes matrix assembly. also adenocarcinomas, though extent this context currently unknown. To achieve a better understanding factors that dictate...

Abstract The thioredoxin superfamily has expanded and diverged extensively throughout evolution such that distant members no longer show appreciable sequence homology. Nevertheless, redox‐active thioredoxin‐fold proteins functioning in diverse physiological contexts often share canonical amino acids near the active‐site (di‐)cysteine motif. Quiescin sulfhydryl oxidase 1 (QSOX1), a catalyst of disulfide bond formation secreted by fibroblasts, is multi‐domain enzyme with certain similarities...

Striatal microdialysate levels of dopamine (DA) in conscious guinea‐pigs were measured following acute (1 day) and chronic (21 days) treatment with deprenyl (2 0.25 mg kg −1 s.c., respectively) or clorgyline (4 1 respectively), as well by combination using the same doses two inhibitors. These treatments caused selective inhibition monoamine oxidase type B (MAO‐B) A (MAO‐A) respectively. Neither nor increased basal KCl‐induced DA levels. Acute accompanied significant reductions striatal...