14,180 research outputs found
Deletion within the CYP17 gene together with inserction of foreign DNA in the cause of combined complete 17OH/17-20 lyase deficiency in an italian patient
No full textData for Envelope Frequency Following Responses to Filtered Word Stimuli
No full textRaw EEG data in .bdf format, collected using a 32-channel ActiveTwo EEG system (BioSemi, the Netherlands). EEG data were measured during presentation of words at an intensity of 70 dB SPL LA eq using ER-2 insert earphones. Words are filtered in different band (0-500 Hz, 0-1000 Hz, 1000-end Hz and 2000-end Hz), with end being 8000 Hz as words were recorded at a sampling rate of 16000 Hz. Stimuli were 3 words presented randomly with an inter-stimulus interval of 1s. Data are published in according with the EPSRC guidelines for data sharing.
Data Supports the paper Vanheusden, F. J., Chesnaye, M. A., Simpson, D. M., & Bell, S. L. (2019). Envelope frequency following responses are stronger for high-pass than low-pass filtered vowels. International Journal of Audiology, 1-9. DOI: 10.1080/14992027.2018.1562243
This dataset, approx 28GB, is available on request via the webform at https://library.soton.ac.uk/datarequest</span
The formation and function of ER-endosome membrane contact sites
No full textRecent advances in membrane contact site (MCS) biology have revealed key roles for MCSs in inter-organellar exchange, the importance of which is becoming increasingly apparent. Roles for MCSs in many essential physiological processes including lipid transfer, calcium exchange, receptor tyrosine kinase signalling, lipid droplet formation, autophagosome formation, organelle dynamics and neurite outgrowth have been reported. The ER forms an extensive and dynamic network of MCSs with a diverse range of functionally distinct organelles. MCSs between the ER and endocytic pathway are particularly abundant, suggesting important physiological roles. Here, our current knowledge of the formation and function of ER contact sites with endocytic organelles from studies in mammalian systems is reviewed. Their relatively poorly defined molecular composition and recently identified functions are discussed. In addition, likely, but yet to be established, roles for these contacts in lipid transfer and calcium signalling are considered. This article is part of a Special Issue entitled: The cellular lipid landscape edited by Tim Levine and Anant K. Menon
The ER-Golgi-Intermediate compartment : dynamics and cargo sorting studied by time-lapse video microscopy
No full textMembrane trafficking in mammalian cells proceeds through several steps including sorting the correct components to be transported, packaging them into appropriate containers and conveying the carriers to the proper organelles with which they fuse. All these steps are tightly regulated by several machineries like coats, fusion proteins, motors, tethers, Rabs and other regulatory components. The investigation of the molecular mechanisms of these machineries unraveled the trafficking events taking place between different compartments; but these findings did not elucidate how organelles can persist and maintain their integrity in a constantly dynamic environment. Two major controversial models are constantly debated: the stability and the maturation of compartments. The stability model favors the notion that compartments are long-lived stations in which cargo material is sorted from the resident components and transits from one organelle to the other in vesicular carriers. The maturation hypothesis suggests that organelles of the secretory pathway are transient stations that form at the level of the ER; once they leave it, they continuously homo-fuse and recycle back machinery components to the previous station. A particular discordance resides in defining the ER-Golgi-intermediate compartment (ERGIC) features: is it a stable or a maturing organelle? The ERGIC defined by the cycling lectin ERGIC-53 consists of tubulovesicular clusters. Here, I show by live imaging that GFP-ERGIC-53 mainly localizes to long-lived stationary and some short-lived highly mobile elements. Unlike the anterograde marker VSV-G-GFP, GFP-ERGIC-53 does not vectorially move to the Golgi upon exit from the ERGIC, as assessed by a novel quantitative vector field method. Dual color imaging of GFP-ERGIC-53 and a secretory protein (signal-sequence-tagged DsRed) reveals that the stationary elements are sites of repeated sorting of retrograde and anterograde cargo, and are interconnected by highly mobile elements. Based on these results, I conclude that the ERGIC is a membrane compartment in the true sense and not simply a collection of mobile carriers mediating protein traffic from endoplasmic reticulum to Golgi. The finding that the ERGIC is a true compartment opens new perspectives for the dissection of ERGIC functions and the molecular machineries that are recruited
Recognizing rare disorders: aromatase deficiency
No full textAromatase deficiency is rare in humans. Affected individuals cannot synthesize endogenous estrogens. Aromatase is the enzyme that catalyzes conversion of androgens into estrogens, and if aromatase is nonfunctional because of an inactivating mutation, estrogen synthesis cannot occur. If the fetus lacks aromatase activity, dehydroepiandrosterone sulfate produced by the fetal adrenal glands cannot be converted to estrogen by the placenta, so is converted to testosterone peripherally and results in virilization of both fetus and mother. Virilization manifests as pseudohermaphroditism in female infants, with hirsutism and acne in the mother; the maternal indicators resolve following delivery. To date, only seven males and seven females with aromatase deficiency have been reported. Affected females are typically diagnosed at birth because of the pseudohermaphroditism. Cystic ovaries and delayed bone maturation can occur during childhood and adolescence in these girls, who present at puberty with primary amenorrhea, failure of breast development, virilization, and hypergonadotrophic hypogonadism. Affected males, on the other hand, do not present with obvious defects at birth, so are diagnosed much later in life, presenting with clinical symptoms, which include tall stature, delayed skeletal maturation, delayed epiphyseal closure, bone pain, eunuchoid body proportions and excess adiposity. Estrogen replacement therapy reverses the symptoms in male and female patients
Gedragsinzichten bieden meer beleidskansen dan er nu worden benut
No full textGedragsinzichten zijn onontbeerlijk om te komen tot effectief beleid, de mens is immers geen homo economicus. Dat geldt echter niet alleen voor uitvoeringsvraagstukken, maar ook voor het ontwerpen van beleid. Hier ligt er nog een groot onbenut potentieel.Policy Analysi
Imaging nuclear, endoplasmic reticulum and plasma membrane events in real time
No full textLive cell imaging can provide important information on cellular dynamics; however, the full utilisation of this technology has been hampered by the limitations of imaging reagents. Metal-based complexes have the potential to overcome many of the issues common to many current imaging agents. The rhenium (I)-based complex fac-[Re(CO)3 (1,10-phenanthroline)(4-pyridyltetrazolate)], herein referred to as ReZolve-ER(™) , shows promise as a live cell imaging agent with rapid cell uptake, low cytotoxicity, resistance to photobleaching and compatibility with multicolour imaging. ReZolve-ER(™) localised to the nuclear membrane/endoplasmic reticulum (ER) and allowed the detection of exocytotic events at the plasma membrane. Thus, we present a new imaging agent for monitoring live cell events in real time, which is ideal for imaging either short- or long-time courses.Christie A. Bader, Alexandra Sorvina, Peter V. Simpson, Phillip J. Wright, Stefano Stagni, Sally E. Plush, Massimiliano Massi and Douglas A. Brook
Embedding research (ER) led by nurses, midwives and allied health professionals (NMAHPs): the NMAHP-ER model.
No full textPrevious embedded researcher models have focused predominantly on an individual being a temporary team member and embedded for a project-limited short-term placement. To develop an innovative research capacity building model to address the challenges of developing, embedding and sustaining, research led by Nurses, Midwives, and Allied Health Professionals (NMAHPs) in complex clinical environments. This healthcare and academic research partnership model offers an opportunity to support the 'how' of enabling NMAHP research capacity building from within the researchers' clinical area of expertise. Collaboration between three healthcare and academic organisations and the iterative process of cocreation, development and refinement took place over 6 months during 2021. The collaboration relied on virtual meetings, emails, telephone calls and document review. A codesigned NMAHP embedded research (ER) model is ready for trialling with the individual being an existing clinician working collaboratively within the healthcare setting and with academia to develop the skills to become the ER. This model supports NMAHP-led research activity in clinical organisations in a visible and manageable way. As a shared, long-term vision, the model will contribute to research capacity and capability of the wider healthcare workforce. It will lead, facilitate and support research in and across clinical organisations in collaboration with higher education institutions. [Abstract copyright: © Author(s) (or their employer(s)) 2022. Re-use permitted under CC BY-NC. No commercial re-use. See rights and permissions. Published by BMJ.
The role of the lectin VIP36 in the early secretory pathway
No full textLectins are of emerging importance for quality control and intracellular transport of glycoproteins in mammalian cells. One of the most prominent lectins involved in intracellular transport is ERGIC-53, which belongs to the family of L-type lectins. ERGIC-53 mediates the ER export of several glycoproteins like cathepsin Z, α1-antitrypsin (α1-AT) or blood coagulation factors. VIP36 belongs to the same family as ERGIC-53, but its cellular function remains poorly understood. VIP36 is a type I membrane protein. It cycles within the early secretory pathway and binds high mannose glycans. In order to gain insight into the function of VIP36 we decided to search for a luminal interaction partner for VIP36.
We used a YFP-protein fragmentation complementation (YFP-PCA) based FACS screen of a human adult liver library to unravel an interaction partner for VIP36. Complementation of YFP is irreversible. Therefore, the YFP-PCA is well suited to detect weak interactions, like those between mammalian lectins and glycoproteins. YFP2-VIP36 was used as the bait in our screen. The human liver library was tagged with YFP1. Our screen identified α1-AT as an interaction partner for VIP36. VIP36 recognized high mannose containing α1-AT, which is consistent with the previously obtained results about the glycan affinity of VIP36. This interaction was increased upon inhibition of complex glycosylation by kifunensine. The complex formed by α1-AT and VIP36 was localized to the Golgi and the ER. α1-AT was previously identified as a cargo for ERGIC-53. Knockdown of ERGIC-53 slowed down α1-AT transport, consistent with a role for ERGIC-53 in ER export of α1-AT. In contrast, knockdown of VIP36 accelerated transport of endogenous α1-AT in HepG2 cells. This effect was specific for α1-AT, as the non-glycosylated protein albumin showed no acceleration in transport. In addition, VIP36 knockdown did not affect general protein secretion. This finding makes it unlikely that VIP36 acts as an anterograde cargo receptor for α1-AT. Further studies on the dynamics of the complex formed by VIP36 and α1-AT revealed that VIP36 recycles α1-AT back to the ER, which argues for a role of VIP36 in post-ER quality control. This notion is further supported by the finding that the chaperone BiP co-immunoprecipitated with the complex of VIP36 and α1-AT. This chaperone was previously described as an interaction partner for VIP36. This argues for a complex consisting of VIP36 and BiP acting together in post-ER quality control to detect misfolded α1-antitrypsin in the Golgi and retrieve it back to the ER.
Apart from searching for an interaction partner, I also determined the effect of depletion of VIP36 on the morphology of the secretory pathway. The rationale behind this is the observation that cargo receptors contribute to the structural integrity of organelles of the secretory pathway. Knockdown of VIP36 had no effect on ER exit sites or on the ERGIC. However, VIP36 knockdown resulted in fragmentation of the Golgi apparatus. The fragmented Golgi was not the consequence of disturbed bidirectional protein transport and not due to effects on microtubules. Knockdown of VIP36 reduced COPI staining on the Golgi. VIP36 is likely to provide COPI binding sites on the Golgi via its cytosolic tail and thereby contribute to Golgi structural integrity. Our results underscore the importance of cargo receptors, not only for intracellular transport within the secretory pathway, but also to maintain the integrity of the secretory pathway itself.
In conclusion, my thesis provides a deeper insight into the function of VIP36 in the early secretory pathway
The secretion inhibitor Exo2 perturbs trafficking of Shiga toxin between endosomes and the trans-Golgi network
No full textThe small-molecule inhibitor Exo2 {4-hydroxy-3-methoxy-(5,6,7,8-tetrahydrol[1]benzothieno[2,3-d]pyrimidin-4-yl)hydraz-one benzaldehyde} has been reported to disrupt the Golgi apparatus completely and to stimulate Golgi–ER (endoplasmic reticulum) fusion in mammalian cells, akin to the well-characterized fungal toxin BFA (brefeldin A). It has also been reported that Exo2 does not affect the integrity of the TGN (trans-Golgi network), or the direct retrograde trafficking of the glycolipid-binding cholera toxin from the TGN to the ER lumen. We have examined the effects of BFA and Exo2, and found that both compounds are indistinguishable in their inhibition of anterograde transport and that both reagents significantly disrupt the morphology of the TGN in HeLa and in BS-C-1 cells. However, Exo2, unlike BFA, does not induce tubulation and merging of the TGN and endosomal compartments. Furthermore, and in contrast with its effects on cholera toxin, Exo2 significantly perturbs the delivery of Shiga toxin to the ER. Together, these results suggest that the likely target(s) of Exo2 operate at the level of the TGN, the Golgi and a subset of early endosomes, and thus Exo2 provides a more selective tool than BFA for examining membrane trafficking in mammalian cells
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