Search results for "Clef"
showing 10 items of 74 documents
Fine-tuning the extent and dynamics of binding cleft opening as a potential general regulatory mechanism in parvulin-type peptidyl prolyl isomerases
2017
AbstractParvulins or rotamases form a distinct group within peptidyl prolyl cis-trans isomerases. Their exact mode of action as well as the role of conserved residues in the family are still not unambiguously resolved. Using backbone S2 order parameters and NOEs as restraints, we have generated dynamic structural ensembles of three distinct parvulins, SaPrsA, TbPin1 and CsPinA. The resulting ensembles are in good agreement with the experimental data but reveal important differences between the three enzymes. The largest difference can be attributed to the extent of the opening of the substrate binding cleft, along which motional mode the three molecules occupy distinct regions. Comparison w…
Negatively Charged Gangliosides Promote Membrane Association of Amphipathic Neurotransmitters
2018
Lipophilic neurotransmitters (NTs) such as dopamine are chemical messengers enabling neurotransmission by adhering onto the extracellular surface of the post-synaptic membrane in a synapse, followed by binding to their receptors. Previous studies have shown that the strength of the NT-membrane association is dependent on the lipid composition of the membrane. Negatively charged lipids such as phosphatidylserine, phosphatidylglycerol, and phosphatidic acid have been indicated to promote NT-membrane binding, however these anionic lipids reside almost exclusively in the intracellular leaflet of the post-synaptic membrane instead of the extracellular leaflet facing the synaptic cleft. Meanwhile…
The oculoauriculofrontonasal syndrome: Further clinical characterization and additional evidence suggesting a nontraditional mode of inheritance
2018
IF 2.264; International audience; The oculoauriculofrontonasal syndrome (OAFNS) is a rare disorder characterized by the association of frontonasal dysplasia (widely spaced eyes, facial cleft, and nose abnormalities) and oculo-auriculo-vertebral spectrum (OAVS)-associated features, such as preauricular ear tags, ear dysplasia, mandibular asymmetry, epibulbar dermoids, eyelid coloboma, and costovertebral anomalies. The etiology is unknown so far. This work aimed to identify molecular bases for the OAFNS. Among a cohort of 130 patients with frontonasal dysplasia, accurate phenotyping identified 18 individuals with OAFNS. We describe their clinical spectrum, including the report of new features…
Total colonic aganglionosis and cleft palate in a newborn with Janus-cysteine 618 mutation of RET proto-oncogene: a case report.
2020
Abstract Background Hirschsprung disease, the most important congenital colonic dysmotility in children results from neural crest migration, differentiation, proliferation, or apoptosis defects where the rearranged during transfection (RET)-Protooncogene pathway has a central role. Although palatal and retinal anomalies in the context of chromosomopathies and some mono−/oligogenic syndromes are reported associated with Hirschsprung disease the role of inactivating RET mutations in these cases is not clarified. Case presentation We report on a dysmorphic newborn with cleft palate and palatal synechia, who showed intestinal obstruction after 24 h of life. Transient ileostomy and surgical biop…
Astrocyte sodium signaling and the regulation of neurotransmission.
2015
The transmembrane Na(+) concentration gradient is an important source of energy required not only to enable the generation of action potentials in excitable cells, but also for various transmembrane transporters both in excitable and non-excitable cells, like astrocytes. One of the vital functions of astrocytes in the central nervous system (CNS) is to regulate neurotransmitter concentrations in the extracellular space. Most neurotransmitters in the CNS are removed from the extracellular space by Na(+) -dependent neurotransmitter transporters (NeuTs) expressed both in neurons and astrocytes. Neuronal NeuTs control mainly phasic synaptic transmission, i.e., synaptically induced transient pos…
Two-year-old girl with tuberous xanthomas.
2018
A 2-year-old girl was referred for evaluation because she had two nodular lesions located on both heels, and another elongated lesion in the intergluteal cleft. On physical examination, two yellow to orange well-defined nodules, suggestive of xanthomas, were bilaterally located on the Achilles tendon areas (figure 1A). Moreover, another yellowish, slightly raised lesion with band-like morphology was seen in the intergluteal cleft (figure 1B). There were no other anomalies on physical examination. Figure 1 (A) Tuberous xanthoma located on the left heel. (B) Planar xanthoma located in the intergluteal cleft. (C) Peripheral blood smear examination showing numerous red cells and two macrothromb…
Structure and Synaptic Function of Metal Binding to the Amyloid Precursor Protein and its Proteolytic Fragments
2017
Alzheimer’s disease (AD) is ultimately linked to the Amyloid Precursor Protein (APP). However, current research reveals an important synaptic function of APP and APP-like proteins (APLP1 and 2). In this context various neurotrophic and neuroprotective functions have been reported for the APP proteolytic fragments sAPPα, sAPPβ, and the monomeric amyloid-beta peptide (Aβ). APP is a metalloprotein and binds copper and zinc ions. Synaptic activity correlates with a release of these ions into the synaptic cleft and dysregulation of their homeostasis is linked to different neurodegenerative diseases. Metal binding to APP or its fragments affects its structure and its proteolytic cleavage and ther…
Type IV Laryngotracheoesophageal Cleft Associated with Type III Esophageal Atresia in 1p36 Deletions Containing the RERE Gene: Is There a Causal Role…
2018
The causes of embryological developmental anomalies leading to laryngotracheoesophageal clefts (LTECs) are not known, but are proposed to be multifactorial, including genetic and environmental factors. Haploinsufficiency of the RERE gene might contribute to different phenotypes seen in individuals with 1p36 deletions. We describe a neonate of an obese mother, diagnosed with type IV LTEC and type III esophageal atresia (EA), in which a 1p36 deletion including the RERE gene was detected. On the second day of life, a right thoracotomy and extrapleural esophagus atresia repair were attempted. One week later, a right cervical approach was performed to separate the cervical esophagus from the tra…
A Perspective : Active Role of Lipids in Neurotransmitter Dynamics
2019
AbstractSynaptic neurotransmission is generally considered as a function of membrane-embedded receptors and ion channels in response to the neurotransmitter (NT) release and binding. This perspective aims to widen the protein-centric view by including another vital component—the synaptic membrane—in the discussion. A vast set of atomistic molecular dynamics simulations and biophysical experiments indicate that NTs are divided into membrane-binding and membrane-nonbinding categories. The binary choice takes place at the water-membrane interface and follows closely the positioning of the receptors’ binding sites in relation to the membrane. Accordingly, when a lipophilic NT is on route to a m…
Lamotrigine use in pregnancy and risk of orofacial cleft and other congenital anomalies
2016
Objective: To test previous signals of a risk of orofacial cleft (OC) and clubfoot with exposure to the antiepileptic lamotrigine, and to investigate risk of other congenital anomalies (CA).Methods: This was a population-based case–malformed control study based on 21 EUROCAT CA registries covering 10.1 million births (1995–2011), including births to 2005 in which the clubfoot signal was generated and a subsequent independent study population of 6.3 million births. A total of 226,806 babies with CA included livebirths, stillbirths, and terminations of pregnancy following prenatal diagnosis. First-trimester lamotrigine monotherapy exposure in OC cases and clubfoot cases was compared to other …