304 research outputs found

    The translocation of transportin–cargo complexes through nuclear pores is independent of both Ran and energy.

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    AbstractActive transport between nucleus and cytoplasm proceeds through nuclear pore complexes (NPCs) and is mediated largely by shuttling transport receptors that use direct RanGTP binding to coordinate loading and unloading of cargo [1–4]. Import receptors such as importin β or transportin bind their substrates at low RanGTP levels in the cytoplasm and release them upon encountering RanGTP in the nucleus, where a high RanGTP concentration is predicted. This substrate release is, in the case of import by the importin α/β heterodimer, coupled directly to importin β release from the NPCs. If the importin β –RanGTP interaction is prevented, import intermediates arrest at the nuclear side of the NPCs [5,6]. This arrest makes it difficult to probe directly the Ran and energy requirements of the actual translocation from the cytoplasmic to the nuclear side of the NPC, which immediately precedes substrate release. Here, we have shown that in the case of transportin, dissociation of transportin–substrate complexes is uncoupled from transportin release from NPCs. This allowed us to dissect the requirements of translocation through the NPC, substrate release and transportin recycling. Surprisingly, translocation of transportin–substrate complexes into the nucleus requires neither Ran nor nucleoside triphosphates (NTPs). It is only nuclear RanGTP, not GTP hydrolysis, that is needed for dissociation of transportin–substrate complexes and for re-export of transportin to the cytoplasm. GTP hydrolysis is apparently required only to restore the import competence of the re-exported transportin and, thus, for multiple rounds of transportin-dependent import. In addition, we provide evidence that at least one type of substrate can also complete NPC passage mediated by importin β independently of Ran and energy

    PEGASUS: the Design of an Intervention to Facilitate Shared Decision-making in Breast Reconstruction

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    © 2020, The Author(s). Studies have found varying levels of satisfaction after breast reconstruction surgery with a substantial group of patients reporting some level of regret about their decision. The variable outcomes reported by women undergoing breast reconstruction surgery suggest a role for improved pre-operative communication and shared decision-making (SDM) between patient and health professional. Pragmatic approaches such as decision aids have been evaluated, but the aim of the Patient Expectations and Goals Assisting Shared Understanding of Surgery (PEGASUS) intervention is to facilitate closer interaction between the patient and clinical team. PEGASUS is a standardised two-stage process, in which patients’ goals are first elicited, ranked in importance and recorded before being used to frame discussion and decision-making with the surgeon managing care. Following the Medical Research Council (MRC) model, feasibility and acceptability studies have already been reported and a 4-year multicentre randomised controlled trial of 180 participants is underway, (completion 2020). This paper therefore focuses on the design of the intervention itself, in line with recent advice that interventions, in comparison with evaluations, commonly lack a theoretical base and are often under reported. We report a retrospective application of the Capability, Opportunity, Motivation-Behaviour (COM-B) model to provide explicit detail of each step in the intervention design. This is intended to facilitate replication by other clinicians and to provide systematic guidance for others wishing to develop PEGASUS as a strategy for implementing SDM in other clinical populations. Trial Registration: ISRCTN 18000391 (DOI 10.1186/ISRCTN18000391) 27/01/2016

    The actin-bundling protein fascin is overexpressed in colorectal adenomas and promotes motility in adenoma cells in vitro

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    Background: Fascin is overexpressed in many cancers, including colorectal, but its role in the malignant transformation of benign colorectal adenomas is unclear. Methods: Immunohistochemical analysis of fascin expression was carried out in resected human colorectal adenoma specimens. The effects of forced overexpression of fascin on adenoma cell motility were also analysed. Results: We show fascin overexpression in adenomas increasing with tumour size, histological type, and degree of dysplasia and increased cell motility in adenoma cell lines following fascin transfection. Conclusion: These data suggest an important role for fascin in the malignant progression of colorectal tumours

    Giant liposarcoma of the back with 4 types of histopathology: a case report

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    The incidence of soft tissue tumours, both malignant and benign, is very common. However, the coexistence of 4 types of histopathology is rare and the aim of this article is to present one treated in our Department. An 87-year-old Greek man was treated in our Department for a huge tumour on his back, under local anaesthesia. The pathology report of the specimen referred 4 types of neoplasia. This case represents this incidence in a giant liposarcoma of the back

    High-Added Value Materials Production from OMW: A Technical and Economical Optimization

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    The extraction of olive oil generates huge quantities of solids and of high organic wastewaters with toxic constituents that have a great impact on land and water environments. Based on a membrane process, authors proposed an alternative method for treatment of olive mill wastewaters (OMWs). In the present paper, a technoeconomic analysis for the implementation of the proposed method in the entire Region of Western Greece (RWG) is presented. This paper takes into account fixed and operational costs, costs for the infrastructure, equipment, land, maintenance, and so forth, considering the treatment of 50,000 tons per harvesting period in the area of RWG. The study showed that the establishment of only one central treatment manufacture could reduce the uncontrolled disposal of OMW. Exploitation of the isolated fractions as manure in fertilizers (nutrients components) or as components in ecological herbicides (phenolics) can depreciate the total cost in a period of about five years

    Nutrient stress alters the glycosylation status of LGR5 resulting in reduced protein stability and membrane localisation in colorectal tumour cells: implications for targeting cancer stem cells

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    BACKGROUND LGR5 is an important marker of intestinal stem cells and performs its vital functions at the cell membrane. Despite the importance of LGR5 to both normal and cancer stem cell biology, it is not known how microenvironmental stress affects the expression and subcellular distribution of the protein. METHODS Nutrient stress was induced through glucose starvation. Glycosylation status was assessed using endoglycosidase or tunicamycin treatment. Flow cytometry and confocal microscopy were used to assess subcellular distribution of LGR5. RESULTS Glucose deprivation altered the glycosylation status of LGR5 resulting in reduced protein stability and cell surface expression. Furthermore, inhibiting LGR5 glycosylation resulted in depleted surface expression and reduced localisation in the cis-Golgi network. CONCLUSIONS Nutrient stress within a tumour microenvironment has the capacity to alter LGR5 protein stability and membrane localisation through modulation of LGR5 glycosylation status. As LGR5 surface localisation is required for enhanced Wnt signalling, this is the first report to show a mechanism by which the microenvironment could affect LGR5 function
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