Mapping the Contact Sites of the Escherichia coli Division-Initiating Proteins FtsZ and ZapA by BAMG Cross-Linking and Site-Directed Mutagenesis.

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Mapping the Contact Sites of the Escherichia coli Division-Initiating Proteins FtsZ and ZapA by BAMG Cross-Linking and Site-Directed Mutagenesis.

Int J Mol Sci. 2018 Sep 26;19(10):

Authors: Roseboom W, Nazir MG, Meiresonne NY, Mohammadi T, Verheul J, Buncherd H, Bonvin AMJJ, de Koning LJ, de Koster CG, de Jong L, den Blaauwen T

Abstract
Cell division in bacteria is initiated by the polymerization of FtsZ at midcell in a ring-like structure called the Z-ring. ZapA and other proteins assist Z-ring formation and ZapA binds ZapB, which senses the presence of the nucleoids. The FtsZ⁻ZapA binding interface was analyzed by chemical cross-linking mass spectrometry (CXMS) under in vitro FtsZ-polymerizing conditions in the presence of GTP. Amino acids residue K42 from ZapA was cross-linked to amino acid residues K51 and K66 from FtsZ, close to the interphase between FtsZ molecules in protofilaments. Five different cross-links confirmed the tetrameric structure of ZapA. A number of FtsZ cross-links suggests that its C-terminal domain of 55 residues, thought to be largely disordered, has a limited freedom to move in space. Site-directed mutagenesis of ZapA reveals an interaction site in the globular head of the protein close to K42. Using the information on the cross-links and the mutants that lost the ability to interact with FtsZ, a model of the FtsZ protofilament⁻ZapA tetramer complex was obtained by information-driven docking with the HADDOCK2.2 webserver.

PMID: 30261644 [PubMed - in process]

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Sentinels at the wall: epithelial-derived cytokines serve as triggers of upper airway type 2 inflammation.

Sentinels at the wall: epithelial-derived cytokines serve as triggers of upper airway type 2 inflammation.

Int Forum Allergy Rhinol. 2018 Sep 10;:

Authors: Patel NN, Kohanski MA, Maina IW, Workman AD, Herbert DR, Cohen NA

Abstract
Recent evidence has demonstrated an expanding role of respiratory epithelial cells in immune surveillance and modulation. Studies have been focusing on the earliest events that link epithelial injury to downstream inflammatory responses. Cytokines produced by and released from respiratory epithelial cells are among these early trigger signals. Epithelial-derived cytokines, namely thymic stromal lymphopoietin (TSLP), interleukin (IL)-25, and IL-33, have come to the forefront of recent investigations. Each of these 3 cytokines has been implicated in chronic rhinosinusitis (CRS), asthma, and atopy. Herein we review studies elucidating the roles of epithelial-derived cytokines in the pathobiology of upper airway disease, with particular emphasis on type 2 inflammatory conditions.

PMID: 30260580 [PubMed - as supplied by publisher]

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Can the Identification of Odorants Within a Mixture Be Trained?

Can the Identification of Odorants Within a Mixture Be Trained?

Chem Senses. 2018 Sep 27;:

Authors: Poupon D, Fernandez P, Boisvert SA, Migneault-Bouchard C, Frasnelli J

Abstract
Identifying odors within mixtures is a difficult task: humans are able to recognize only up to 4 odors within a mixture. We wanted to test the effects of olfactory training on this ability. We used 7 odorants to create 35 olfactory stimuli of 1, 2, 3, 4, or 5 odorants. The task consisted of identifying the odorants present within the mixture. We trained novices on this task for 5 days: they came to the laboratory to perform the task once a day before coming back for the final testing. Then, we compared them to sommeliers, thus olfaction experts, and untrained novices. Results showed that sommeliers outperformed the other groups with mixtures of up to 4 odorants but not with mixtures of 5 odorants. The short olfactory training allowed trained participants to perform as well as sommeliers when it came to identifying single odorants but was not enough to improve their performance when stimuli were mixtures of 2 or more odorants. This study supports the idea that the number of odors we can recognize within a mixture is limited but suggests training can improve the performance: a short olfactory training is enough to enhance the ability to identify single odorants, whereas expertise refines identification ability of mixtures of up to 4 odorants.

PMID: 30260369 [PubMed - as supplied by publisher]

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Signal detection and coding in the accessory olfactory system.

Signal detection and coding in the accessory olfactory system.

Chem Senses. 2018 Sep 25;:

Authors: Mohrhardt J, Nagel M, Fleck D, Ben-Shaul Y, Spehr M

Abstract
In many mammalian species, the accessory olfactory system (AOS) plays a central role in guiding behavioral and physiological responses to social and reproductive interactions. Because of its relatively compact structure and its direct access to amygdalar and hypothalamic nuclei, the accessory olfactory pathway provides an ideal system to study sensory control of complex mammalian behavior. During the last several years, many studies employing molecular, behavioral, and physiological approaches have significantly expanded and enhanced our understanding of this system. The purpose of the current review is to integrate older and newer studies to present an updated and comprehensive picture of vomeronasal signaling and coding with an emphasis on early AOS processing stages. These include vomeronasal sensory neurons (VSNs) in the vomeronasal organ (VNO), and the circuitry of the accessory olfactory bulb (AOB). Because the overwhelming majority of studies on AOS function employ rodents, this review is largely focused on this phylogenetic order, and on mice in particular. Taken together, the emerging view from both older literature and more recent studies is that the molecular, cellular and circuit properties of chemosensory signaling along the accessory olfactory pathway are in many ways unique. Yet, it has also become evident that, like the main olfactory system (MOS), the AOS also has the capacity for adaptive learning, experience, and state-dependent plasticity. In addition to describing what is currently known about AOS function and physiology, we highlight what we believe are important gaps in our knowledge, which thus define exciting directions for future investigation.

PMID: 30256909 [PubMed - as supplied by publisher]

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Sharing an environment with sick conspecifics alters odors of healthy animals.

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Sharing an environment with sick conspecifics alters odors of healthy animals.

Sci Rep. 2018 Sep 24;8(1):14255

Authors: Gervasi SS, Opiekun M, Martin T, Beauchamp GK, Kimball BA

Abstract
Body odors change with health status and the odors of sick animals can induce avoidance behaviors in healthy conspecifics. Exposure to sickness odors might also alter the physiology of healthy conspecifics and modify the odors they produce. We hypothesized that exposure to odors of sick (but non-infectious) animals would alter the odors of healthy cagemates. To induce sickness, we injected mice with a bacterial endotoxin, lipopolysaccharide. We used behavioral odor discrimination assays and analytical chemistry techniques followed by predictive classification modeling to ask about differences in volatile odorants produced by two types of healthy mice: those cohoused with healthy conspecifics and those cohoused with sick conspecifics. Mice trained in Y-maze behavioral assays to discriminate between the odors of healthy versus sick mice also discriminated between the odors of healthy mice cohoused with sick conspecifics and odors of healthy mice cohoused with healthy conspecifics. Chemical analyses paired with statistical modeling revealed a parallel phenomenon. Urine volatiles of healthy mice cohoused with sick partners were more likely to be classified as those of sick rather than healthy mice based on discriminant model predictions. Sickness-related odors could have cascading effects on neuroendocrine or immune responses of healthy conspecifics, and could affect individual behaviors, social dynamics, and pathogen spread.

PMID: 30250285 [PubMed - in process]

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Anxiety Body Odors as Context for Dynamic Faces: Categorization and Psychophysiological Biases.

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Anxiety Body Odors as Context for Dynamic Faces: Categorization and Psychophysiological Biases.

Perception. 2018 Sep 19;:301006618797227

Authors: Rocha M, Parma V, Lundström JN, Soares SC

Abstract
Body odors (BOs) can convey social information. In particular, their effects are maximal when their presence is paired with meaningful social contexts. Static faces have been widely used as social stimuli. However, they miss a key feature of our phenomenological experience, characterized by multisensory dynamic stimulations. Here, we investigate how BO sampled from individuals experiencing a transitory anxiety state, (a) induce a stress response and (b) bias the recognition of dynamic facial expressions, compared with BO of relaxed individuals. Participants ( n=46) categorized the emotion of a face, morphing from a neutral expression to either an angry or happy expression, during exposure to either BO condition. In addition, their cardiac activity was measured. Exposure to anxiety BO increased the accuracy of dynamic facial recognition and reduced cardiac parasympathetic activity. These results suggest that in social situations that simulate part of the multisensory and dynamic features of real-life social contexts, anxiety BOs will induce a stress response in recipients, modulating both arousal and cognitive-emotional skills but facilitating emotional facial processing.

PMID: 30231844 [PubMed - as supplied by publisher]

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Individual Differences in the Perception of Color Solutions.

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Individual Differences in the Perception of Color Solutions.

Foods. 2018 Sep 18;7(9):

Authors: Hoppu U, Puputti S, Aisala H, Laaksonen O, Sandell M

Abstract
The color of food is important for flavor perception and food selection. The aim of the present study was to evaluate the visual color perception of liquid samples among Finnish adult consumers by their background variables. Participants (n = 205) ranked six different colored solutions just by looking according to four attributes: from most to least pleasant, healthy, sweet and sour. The color sample rated most frequently as the most pleasant was red (37%), the most healthy white (57%), the most sweet red and orange (34% both) and the most sour yellow (54%). Ratings of certain colors differed between gender, age, body mass index (BMI) and education groups. Females regarded the red color as the sweetest more often than males (p = 0.013) while overweight subjects rated the orange as the sweetest more often than normal weight subjects (p = 0.029). Personal characteristics may be associated with some differences in color associations.

PMID: 30231463 [PubMed]

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