The Crescerin protein family uses arrayed TOG domains to regulate microtubules in cilia

The eukaryotic primary cilium is a solitary, antenna-like projection from the surface of a cell, critical for sensing the extracellular environment. Many mammalian cell types have a primary cilium, which acts as a hub for different signaling pathways depending upon the cell type. Primary cilia play an important role in cell differentiation and cell fate determination in response to rapidly switching cues during embryonic development. Due to the widespread occurrence of primary cilium in different tissues, mutation in proteins affecting cilia structure can present a wide variety of developmental defects and sensory disorders, collectively termed ciliopathies. A microtubule-based scaffold, known as the axoneme, forms the core of the primary cilium. The structure of the axoneme is highly conserved across different eukaryotic species. However, mechanisms that regulate the structure and microtubule dynamics in the axoneme are poorly understood. TOG domain array-containing proteins ch-TOG and CLASP are key regulators of cytoplasmic microtubules. Whether TOG array proteins also regulate ciliary microtubules is unknown. In this dissertation, we have identified the conserved Crescerin protein family as a cilia-specific TOG array-containing microtubule regulator. We present the crystal structure of mammalian Crescerin1 TOG2, revealing a canonical TOG fold with conserved tubulin-binding determinants. Crescerin1’s TOG domains possess inherent microtubule-binding activity and promote microtubule polymerization in vitro. Using Cas9-triggered homologous recombination in Caenorhabditis elegans, we demonstrate that the worm Crescerin family member CHE-12 requires TOG domain-dependent tubulin-binding activity for sensory cilia development. Thus, Crescerin expands the TOG domain array-based MT regulatory paradigm beyond ch-TOG and CLASP, representing a distinct regulator of cilia structure.Doctor of Philosoph

Acquired vaginal stenosis following caesarean delivery: a case report

Postpartum genital tract adhesions are infrequent and their reason has not been appraised. Though, severe dystocia and frequent pelvic examinations have been projected as possible causes. Here, we report a case of vaginal adhesions following caesarean section for obstructed labour that presented as irregular menstruation with desire to remove the PPIUCD. The patient was successfully treated with surgical resection

Copper Ion Doped Mullite Composite in Poly (vinylidene Fluoride) Matrix: Effect on Microstructure, Phase Behavior and Electrical Properties

Highly crystallized copper ion doped mullite composites have been synthesized at 1100°C and 1400°C via sol-gel technique with five different strengths of copper ion and was incorporated in poly-vinylidene fluoride (PVDF) to make doped mullite composite/polymer films. We have studied the effects of this dopant on microstructure, phase transformation, and electrical properties of the polymer films over a wide range of frequency from 1.0 KHz to 2.0 MHz. Characterizations were done by various analytical tools at room temperature. Prominent mullite phases were observed from XRD, FTIR spectroscopy and FESEM characterization of composite polymer. The concentration of the dopant and the sintering temperature were found to be the two basic factors which affect the phase transition of the polymer. The composite film showed maximum dielectric constant of 19.96 at 1 KHz for 1.2M concentration of copper ion doped mullite sintered at 1400°C, compared to 3.09 for the pure polymer. Furthermore, both dielectric constant and electrical conductivity of the composite were found to be highly frequency and temperature dependent. After doping, the A.C. conductivity of the composite was found to increase with increasing temperature following Jonscher's power law and the electrical resistivity reduced too. Moreover, the results revealed that the phase behaviors and micro structural changes of the copper ion doped mullite composite/polymer film affected its electrical properties with possible impact on its applications

Crescerin uses a TOG domain array to regulate microtubules in the primary cilium

Eukaryotic cilia are cell-surface projections critical for sensing the extracellular environment. Defects in cilia structure and function result in a broad range of developmental and sensory disorders. However, mechanisms that regulate the microtubule (MT)-based scaffold forming the cilia core are poorly understood. TOG domain array–containing proteins ch-TOG and CLASP are key regulators of cytoplasmic MTs. Whether TOG array proteins also regulate ciliary MTs is unknown. Here we identify the conserved Crescerin protein family as a cilia-specific, TOG array-containing MT regulator. We present the crystal structure of mammalian Crescerin1 TOG2, revealing a canonical TOG fold with conserved tubulin-binding determinants. Crescerin1's TOG domains possess inherent MT-binding activity and promote MT polymerization in vitro. Using Cas9-triggered homologous recombination in Caenorhabditis elegans, we demonstrate that the worm Crescerin family member CHE-12 requires TOG domain–dependent tubulin-binding activity for sensory cilia development. Thus, Crescerin expands the TOG domain array–based MT regulatory paradigm beyond ch-TOG and CLASP, representing a distinct regulator of cilia structure

Distinctive visual tasks for characterizing mild cognitive impairment and dementia using oculomotor behavior

IntroductionOne’s eye movement (in response to visual tasks) provides a unique window into the cognitive processes and higher-order cognitive functions that become adversely affected in cases with cognitive decline, such as those mild cognitive impairment (MCI) and dementia. MCI is a transitional stage between normal aging and dementia.MethodsIn the current work, we have focused on identifying visual tasks (such as horizontal and vertical Pro-saccade, Anti-saccade and Memory Guided Fixation tasks) that can differentiate individuals with MCI and dementia from their cognitively unimpaired healthy aging counterparts based on oculomotor Performance indices. In an attempt to identify the optimal combination of visual tasks that can be used to differentiate the participant groups, clustering was performed using the oculomotor Performance indices.ResultsResults of our study with a group of 60 cognitively unimpaired healthy aging individuals, a group with 60 individuals with MCI and a group with 60 individuals with dementia indicate that the horizontal and vertical Anti-saccade tasks provided the optimal combination that could differentiate individuals with MCI and dementia from their cognitively unimpaired healthy aging counterparts with clustering accuracy of ∼92% based on the saccade latencies. Also, the saccade latencies during both of these Anti-saccade tasks were found to strongly correlate with the Neuropsychological test scores.DiscussionThis suggests that the Anti-saccade tasks can hold promise in clinical practice for professionals working with individuals with MCI and dementia

Pattern of locoregional failure in postoperative cases of locally advanced carcinoma of buccal mucosa treated with unilateral versus bilateral neck radiation: lesson learned from a basic practice setup

Background: Carcinoma of buccal mucosa forms a sizeable percentage of the diagnosed oral cavity cancers in India. There is limited data on elective treatment of the contralateral neck for well-lateralized carcinoma with no involved nodes in the contralateral neck. We conducted this study to compare locoregional control in patients treated with unilateral vs. bilateral neck irradiation. Materials and methods: 48 patients with carcinoma of buccal mucosa were selected. Patients were divided into unilateral and bilateral arms based on radiation treatment of the ipsilateral or bilateral neck. All patients received adjuvant radiation with Cobalt 60 unit. Patient-specific and follow-up data were collected from records and dosimetric data from TPS. Chi-square and unpaired t-test was used to compare data between arms and Kaplan Meier plot; Cox regression was used for survival analysis. Results: After a median follow-up of 23 months, 15 (31.3%) patients had developed disease recurrence, 8 and 7 in the unilateral and bilateral arms, respectively (p = 0.591). There was no contralateral neck failure during the follow-up period. The 2-year disease-free survival was 68.2% and 72.2% in the unilateral and bilateral arms, respectively. Among risk factors for disease recurrence, Depth of Invasion, delay in starting radiation and PTV coverage were significant contributing factors. Cox multivariate regression suggested DOI and delay in starting radiation to be significant prognostic factors for DFS. Conclusion: Bilateral neck radiation does not provide any advantage over ipsilateral neck radiation for properly selected well lateralized buccal mucosal squamous cell carcinoma. Ipsilateral neck radiation facilitates better sparing of organs at risk

Intrinsically disordered protein biosensor tracks the physical-chemical effects of osmotic stress on cells.

Cell homeostasis is perturbed when dramatic shifts in the external environment cause the physical-chemical properties inside the cell to change. Experimental approaches for dynamically monitoring these intracellular effects are currently lacking. Here, we leverage the environmental sensitivity and structural plasticity of intrinsically disordered protein regions (IDRs) to develop a FRET biosensor capable of monitoring rapid intracellular changes caused by osmotic stress. The biosensor, named SED1, utilizes the Arabidopsis intrinsically disordered AtLEA4-5 protein expressed in plants under water deficit. Computational modeling and in vitro studies reveal that SED1 is highly sensitive to macromolecular crowding. SED1 exhibits large and near-linear osmolarity-dependent changes in FRET inside living bacteria, yeast, plant, and human cells, demonstrating the broad utility of this tool for studying water-associated stress. This study demonstrates the remarkable ability of IDRs to sense the cellular environment across the tree of life and provides a blueprint for their use as environmentally-responsive molecular tools

Dichloroindium hydride (Cl<SUB>2</SUB>InH): a convenient reagent for stereoselective reduction of vic-dibromides to (E)-alkenes

Dichloroindium hydride (Cl2InH) generated in situ from the combination of a catalytic amount of indium(III) chloride and sodium borohydride in acetonitrile reduces activated vic-dibromides to the corresponding (E)-alkenes in excellent yieids

Progressive recruitment of distal MEC-4 channels determines touch response strength in C. elegans

Touch deforms, or strains, the skin beyond the immediate point of contact. The spatiotemporal nature of the touch-induced strain fields depend on the mechanical properties of the skin and the tissues below. Somatosensory neurons that sense touch branch out within the skin and rely on a set of mechano-electrical transduction channels distributed within their dendrites to detect mechanical stimuli. Here, we sought to understand how tissue mechanics shape touch-induced mechanical strain across the skin over time and how individual channels located in different regions of the strain field contribute to the overall touch response. We leveraged Caenorhabditis elegans’ touch receptor neurons as a simple model amenable to in vivo whole-cell patch-clamp recording and an integrated experimental-computational approach to dissect the mechanisms underlying the spatial and temporal dynamics we observed. Consistent with the idea that strain is produced at a distance, we show that delivering strong stimuli outside the anatomical extent of the neuron is sufficient to evoke MRCs. The amplitude and kinetics of the MRCs depended on both stimulus displacement and speed. Finally, we found that the main factor responsible for touch sensitivity is the recruitment of progressively more distant channels by stronger stimuli, rather than modulation of channel open probability. This principle may generalize to somatosensory neurons with more complex morphologies

Progressive recruitment of distal MEC-4 channels determines touch response strength in C. elegans

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