Background:The enzyme carnitine palmitoyltransferase 1 regulates the rate of fatty acid oxidation. Results: The regulatory domain of the enzyme constitutes an amphiphilic structural switch. Conclusion:The switch can integrate enzyme inhibitor concentration and membrane characteristics into one regulatory signal. Significance: This represents a highly sophisticated regulatory mechanism for enzymes residing at the membrane-water interface.

Many bacteria use population density to control gene expression via quorum sensing. In Vibrio cholerae, quorum sensing coordinates virulence, biofilm formation, and DNA uptake by natural competence. The transcription factors AphA and HapR, expressed at low and high cell density respectively, play a key role. In particular, AphA triggers the entire virulence cascade upon host colonisation. In this work we have mapped genome-wide DNA binding by AphA. We show that AphA is versatile, exhibiting distinct modes of DNA binding and promoter regulation. Unexpectedly, whilst HapR is known to induce natural competence, we demonstrate that AphA also intervenes. Most notably, AphA is a direct repressor of tfoX, the master activator of competence. Hence, production of AphA markedly suppressed DNA uptake; an effect largely circumvented by ectopic expression of tfoX. Our observations suggest dual regulation of competence. At low cell density AphA is a master repressor whilst HapR activates the process at high cell density. Thus, we provide deep mechanistic insight into the role of AphA and highlight how V. cholerae utilises this regulator for diverse purposes.

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BackgroundAutism spectrum disorder (ASD) is a common lifelong condition affecting 1 in 100 people. ASD affects how a person relates to others and the world around them. Difficulty responding to sensory information (noise, touch, movement, taste, sight) is common, and might include feeling overwhelmed or distressed by loud or constant low-level noise (e.g. in the classroom). Affected children may also show little or no response to these sensory cues. These ‘sensory processing difficulties’ are associated with behaviour and socialisation problems, and affect education, relationships, and participation in daily life. Sensory integration therapy (SIT) is a face-to-face therapy or treatment provided by trained occupational therapists who use play-based sensory-motor activities and the just-right challenge to influence the way the child responds to sensation, reducing distress, and improving motor skills, adaptive responses, concentration, and interaction with others. With limited research into SIT, this protocol describes in detail how the intervention will be defined and evaluated.MethodsThis is a two-arm pragmatic individually 1:1 randomised controlled trial with an internal pilot of SIT versus usual care for primary school aged children (aged 4 to 11 years) with ASD and sensory processing difficulties; 216 children will be recruited from multiple sources. Therapy will be delivered in clinics meeting full fidelity criteria for manualised SIT over 26 weeks (face-to-face sessions: two per week for 10 weeks, two per month for 2 months; telephone call: one per month for 2 months). Follow-up assessments will be completed at 6 and 12 months post-randomisation. Prior to recruitment, therapists will be invited to participate in focus groups/interviews to explore what is delivered as usual care in trial regions; carers will be invited to complete an online survey to map out their experience of services. Following recruitment, carers will be given diaries to record their contact with services. Following intervention, carer and therapist interviews will be completed.DiscussionResults of this trial will provide high-quality evidence on the clinical and cost effectiveness of SIT aimed at improving behavioural, functional, social, educational, and well-being outcomes for children and well-being outcomes for carers and families.Trial registrationISRCTN14716440. Registered on 8 November 2016.Electronic supplementary materialThe online version of this article (10.1186/s13063-019-3205-y) contains supplementary material, which is available to authorized users.

Food-related behavior problems are well documented in Prader-Willi syndrome (PWS), with impaired satiety, preoccupation with food and negative food-related behaviors (such as taking and storing food) frequently reported as part of the behavioral phenotype of older children and adults. Food-related behavior problems in other genetic neurodevelopmental syndromes remain less well studied, including those seen in Angelman Syndrome (AS), the 'sister imprinted disorder' of PWS. Food-related behavior problems were assessed in 152 participants each with one of five genetic neurodevelopmental syndromes – PWS, AS, 1p36 deletion, Cornelia de Lange, and fragile X. Predictably, levels of food-related behavior problems reported in participants with PWS significantly exceeded those of at least one other groups in most areas (impaired satiety; preoccupation with food; taking and storing food; composite negative behavior). However, in some areas people with AS were reported to display food-related problems at least as severe as those with PWS, with the AS group reported to display significantly more food-related behavior problems than at least one comparison group on measures of taking and storing food, composite negative behaviors, impaired satiety and preoccupation with food. Over 50% of participants in the AS group scored above the median point of the distribution of PWS scores on a measure of taking and storing food. These findings indicate further investigation of eating problems in AS are warranted and have implications for current theoretical interpretations of the behavioral differences between AS and PWS.