43 research outputs found
The Crystal Structure of the Escherichia coli Autoinducer-2 Processing Protein LsrF
Many bacteria produce and respond to the quorum sensing signal autoinducer-2 (AI-2). Escherichia coli and Salmonella typhimurium are among the species with the lsr operon, an operon containing AI-2 transport and processing genes that are up regulated in response to AI-2. One of the Lsr proteins, LsrF, has been implicated in processing the phosphorylated form of AI-2. Here, we present the structure of LsrF, unliganded and in complex with two phospho-AI-2 analogues, ribose-5-phosphate and ribulose-5-phosphate. The crystal structure shows that LsrF is a decamer of (αβ)8-barrels that exhibit a previously unseen N-terminal domain swap and have high structural homology with aldolases that process phosphorylated sugars. Ligand binding sites and key catalytic residues are structurally conserved, strongly implicating LsrF as a class I aldolase
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Is it me? Self-recognition bias across sensory modalities and its relationship to autistic traits
Background Atypical self-processing is an emerging theme in autism research, suggested by lower self-reference effect in memory, and atypical neural responses to visual self-representations. Most research on physical self-processing in autism uses visual stimuli. However, the self is a multimodal construct, and therefore, it is essential to test self-recognition in other sensory modalities as well. Self-recognition in the auditory modality remains relatively unexplored and has not been tested in relation to autism and related traits. This study investigates self-recognition in auditory and visual domain in the general population and tests if it is associated with autistic traits. Methods Thirty-nine neurotypical adults participated in a two-part study. In the first session, individual participant’s voice was recorded and face was photographed and morphed respectively with voices and faces from unfamiliar identities. In the second session, participants performed a ‘self-identification’ task, classifying each morph as ‘self’ voice (or face) or an ‘other’ voice (or face). All participants also completed the Autism Spectrum Quotient (AQ). For each sensory modality, slope of the self-recognition curve was used as individual self-recognition metric. These two self-recognition metrics were tested for association between each other, and with autistic traits. Results Fifty percent ‘self’ response was reached for a higher percentage of self in the auditory domain compared to the visual domain (t = 3.142; P < 0.01). No significant correlation was noted between self-recognition bias across sensory modalities (τ = −0.165, P = 0.204). Higher recognition bias for self-voice was observed in individuals higher in autistic traits (τ AQ = 0.301, P = 0.008). No such correlation was observed between recognition bias for self-face and autistic traits (τ AQ = −0.020, P = 0.438). Conclusions Our data shows that recognition bias for physical self-representation is not related across sensory modalities. Further, individuals with higher autistic traits were better able to discriminate self from other voices, but this relation was not observed with self-face. A narrow self-other overlap in the auditory domain seen in individuals with high autistic traits could arise due to enhanced perceptual processing of auditory stimuli often observed in individuals with autism
Embodiment and body awareness in meditators
[EN] Mindfulness practice consists of focusing attention in an intentional way on the experience of the present moment, including bodily sensations, thoughts or feelings, and the environment, with an attitude of acceptance and without judging. The body and, especially, body awareness are key elements in mindfulness. Embodiment or the feeling of being located within one's physical body is a related concept, and it is composed of the sense of ownership, location, and agency of the body. The rubber hand illusion (RHI) is an experimental paradigm that has been used to understand the mechanisms of embodiment, and evidence shows that body awareness modulates this illusion. To our knowledge, no studies have analyzed embodiment processes in meditators. The aim of this study is to use the RHI to analyze the mechanisms of embodiment and its relationship with body awareness and mindfulness in meditators and non-meditators. The sample was composed of long-term meditators (n = 15) and non-meditators (n = 15). Objective and self-report measures for embodiment with the RHI and self-report questionnaires of body awareness and mindfulness were administered. One-way ANOVA revealed significant differences between groups in sense of agency in the rubber hand. Meditators experienced less sense of agency in the rubber hand than non-meditators. Pearson's correlations showed that this lower sense of agency in the rubber hand was associated with higher body awareness and mindfulness. Results highlight the role of body awareness and mindfulness in embodiment mechanisms. This study has clinical implications, especially in psychopathological disorders that can be influenced by disturbances in these processes.The authors would like to acknowledge the "BODYTA" project (Spanish Ministry of Economy and Competitiveness, PSI2014-51928-R), "PROMOSAM" (Spanish Ministry of Economy and Competitiveness, PSI2014-56303-REDT), and "Excellence Research Program PROMETEO II" (Generalitat Valenciana, Conselleria de Educacion, Cultura y Deporte, PROMETEOII/2013/003). CIBERobn is an initiate of the ISCIII. PROMOSAM Excellence in Research Program (PSI2014-56303-REDT), MINECO, Spain.Cebolla, A.; Miragall, M.; Palomo, P.; Llorens Rodríguez, R.; Soler, J.; Demarzo, M.; García Campayo, J.... (2016). Embodiment and body awareness in meditators. Mindfulness. 7(6):1297-1305. https://doi.org/10.1007/s12671-016-0569-xS1297130576Aguado, J., Luciano, J. V., Cebolla, A., Serrano-Blanco, A., Soler, J., & García-Campayo, J. (2015). 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Communication in bacteria: an ecological and evolutionary perspective
Individual bacteria can alter their behaviour through chemical interactions between organisms in microbial communities - this is generally referred to as quorum sensing. Frequently, these interactions are interpreted in terms of communication to mediate coordinated, multicellular behaviour. We show that the nature of interactions through quorum-sensing chemicals does not simply involve cooperative signals, but entails other interactions such as cues and chemical manipulations. These signals might have a role in conflicts within and between species. The nature of the chemical interaction is important to take into account when studying why and how bacteria react to the chemical substances that are produced by other bacteria
The feeling of me feeling for you: Interoception, alexithymia and empathy in autism.
Following recent evidence for a link between interoception, emotion and empathy, we investigated relationships between these factors in Autism Spectrum Disorder (ASD). 26 adults with ASD and 26 healthy participants completed tasks measuring interoception, alexithymia and empathy. ASD participants with alexithymia demonstrated lower cognitive and affective empathy than ASD participants without alexithymia. ASD participants showed reduced interoceptive sensitivity (IS), and also reduced interoceptive awareness (IA). IA was correlated with empathy and alexithymia, but IS was related to neither. Alexithymia fulfilled a mediating role between IA and empathy. Our findings are suggestive of an alexithymic subgroup in ASD, with distinct interoceptive processing abilities, and have implications for diagnosis and interventions