Negative regulation of syntaxin4/SNAP-23/VAMP2-mediated membrane fusion by Munc18c <i>In Vitro</i>

Background: Translocation of the facilitative glucose transporter GLUT4 from an intracellular store to the plasma membrane is responsible for the increased rate of glucose transport into fat and muscle cells in response to insulin. This represents a specialised form of regulated membrane trafficking. Intracellular membrane traffic is subject to multiple levels of regulation by conserved families of proteins in all eukaryotic cells. Notably, all intracellular fusion events require SNARE proteins and Sec1p/Munc18 family members. Fusion of GLUT4-containing vesicles with the plasma membrane of insulin-sensitive cells involves the SM protein Munc18c, and is regulated by the formation of syntaxin 4/SNAP23/VAMP2 SNARE complexes. Methodology/Principal Findings Here we have used biochemical approaches to characterise the interaction(s) of Munc18c with its cognate SNARE proteins and to examine the role of Munc18c in regulating liposome fusion catalysed by syntaxin 4/SNAP23/VAMP2 SNARE complex formation. We demonstrate that Munc18c makes contacts with both t- and v-SNARE proteins of this complex, and directly inhibits bilayer fusion mediated by the syntaxin 4/SNAP23/VAMP2 SNARE complex. Conclusion/Significance Our reductionist approach has enabled us to ascertain a direct inhibitory role for Munc18c in regulating membrane fusion mediated by syntaxin 4/SNAP23/VAMP2 SNARE complex formation. It is important to note that two different SM proteins have recently been shown to stimulate liposome fusion mediated by their cognate SNARE complexes. Given the structural similarities between SM proteins, it seems unlikely that different members of this family perform opposing regulatory functions. Hence, our findings indicate that Munc18c requires a further level of regulation in order to stimulate SNARE-mediated membrane fusion

DNA Methylation Signatures within the Human Brain

DNA methylation is a heritable modification of genomic DNA central to development, imprinting, transcriptional regulation, chromatin structure, and overall genomic stability. Aberrant DNA methylation of individual genes is a hallmark of cancer and has been shown to play an important role in neurological disorders such as Rett syndrome. Here, we asked whether normal DNA methylation might distinguish individual brain regions. We determined the quantitative DNA methylation levels of 1,505 CpG sites representing 807 genes with diverse functions, including proliferation and differentiation, previously shown to be implicated in human cancer. We initially analyzed 76 brain samples representing cerebral cortex (n=35), cerebellum (n=34), and pons (n=7), along with liver samples (n=3) from 43 individuals. Unsupervised hierarchical analysis showed clustering of 33 of 35 cerebra distinct from the clustering of 33 of 34 cerebella, 7 of 7 pons, and all 3 livers. By use of comparative marker selection and permutation testing, 156 loci representing 118 genes showed statistically significant differences—a ⩾17% absolute change in DNA methylation (P<.004)—among brain regions. These results were validated for all six genes tested in a replicate set of 57 samples. Our data suggest that DNA methylation signatures distinguish brain regions and may help account for region-specific functional specialization

The upgrading of fire safety in historic buildings

There is a seemingly continual erosion of our cultural heritage due to fires in historic buildings. Some of these fires result in partial loss of the asset, some result in total loss – in all cases irreplaceable historic fabric is destroyed. Accurate recording for fires in historic buildings is problematic, but such data as has been collated indicates that the level of loss is high. One of the key factors in achieving robust fire safety in historic buildings is the upgrading of physical fire protection measures. It has been suggested that we should assume a fire event is probable, and together with a context in which outside help might be some time in arriving, such measures are considered crucial in containing the fire and raising the alarm as quickly as possible. This article considers passive and active fire protection measures, using case study material to provide illustrative examples. Where it might be expected that conservation requirements, aiming to avoid negative impact to character and significance, might hinder disruptive physical interventions to improve fire protection, in fact a great deal can be achieved. Such a pragmatic approach is arguably necessary for the safety and preservation of built heritage, when the alternative might otherwise be yet another burnt-out shell

Non-ST-segment elevation acute coronary syndrome in elderly patients and long-livers. Features of treatment. Literature review and case report

Despite the growing population of elderly people and long-livers every year, the treatment of acute coronary syndrome in these groups is not fully developed and is not regulated in clinical guidelines due to the lack of large randomized clinical trials. The article presents a literature review covering the following issues arising during clinical decision-making in the treatment of non-ST-segment elevation acute coronary syndrome in this group of patients: selection of invasive treatment strategy, scope of myocardial revascularization, appointment of dual antiplatelet therapy taking into account the bleeding risk, decreased renal function and senile asthenia. In addition, a case report of successful treatment of a 101-year-old female patient with non-ST-segment elevation myocardial infarction, who underwent percutaneous coronary intervention with stenting of infarct-related artery, was presented

Brian: The Typographical Error that Brought Early Career Neuroscientists and Artists Together

In the project “Do You Mind?” early career neuroscientists and artists collaborated to produce artworks for exhibition

A blot on the landscape? Civic memory and municipal public parks in early twentieth century Manchester

This paper examines the decision to locate the façade of Manchester’s old Town Hall in a public park (Heaton Park) in 1912. It argues that, in so doing, the city’s Parks and Cemeteries committee was attempting to refine the didactic space of the park as a site of civic memory. The early Victorian urban parks had sought to educate their visitors through their museums, art galleries and exhibition spaces, glasshouses and carefully-planned and planted walkways. The insertion into this environment of part of a former civic building was intended to remind the visitors of their civic history and to warn surrounding districts of the expansionist tendencies of the city of Manchester. The failure to identify the façade or to connect it to its surroundings meant that its meaning was ultimately lost to many parks visitors and it remained in place as a civic folly. Public parks presented the municipal authorities with an opportunity to highlight the provision of recreation and leisure facilities, but also an occasion to re-invent the municipal tradition. However, as this paper shows, such gestures were often futile in the complex and contested space of the public park

АССОЦИАЦИЯ СОЧЕТАНИЯ АБЕРРАЦИЙ ЧИСЛА КОПИЙ ГЕНОВ WNT-СИГНАЛИНГА И АМПЛИФИКАЦИЙ ГЕНОВ СТВОЛОВОСТИ В ОПУХОЛИ МОЛОЧНОЙ ЖЕЛЕЗЫ С МЕТАСТАЗИРОВАНИЕМ

We studied the association between the presence of 2 or more stemness gene amplifications as well as copy number aberrations (CNAs) of WNT signaling genes in residual breast tumor and metastasis. WNT pathway genes associated with metastasis were identified.Material and Methods. The study included 30 patients with breast cancer, who had 2 or more stemness gene amplifications in the residual tumor after neoadjuvant chemotherapy. Fifteen of the thirty patients developed hematogenous metastases; they constituted a group with metastases, the remaining 15 patients entered the second group without metastases. The tumor DNA was examined using a CytoScanHD Array microarray (Affymetrix, USA).Results. By subtracting amplification and deletion frequencies in 852 cytobands between groups with metastases and without metastases, 21 cytobands were identified with the largest difference in deletion and amplification frequencies. They contain 19/150 of WNT genes (12 activators: SKP1, WNT8A, MAPK9, CCND3, FZD9, WNT8B, CCND1, PLCB2, PRKCB, FZD2, WNT3, WNT9B and 7 negative regulators: GSK3B, APC, CSNK2B, SFRP5, BTRC, TCF7L2, CSNK2A2). A point system was developed: when amplifying WNT-signaling activators or deletion of negative regulators, one point was added to the total score, and vice versa when deleting WNT-signaling activators or amplification of negative regulators, one point was taken from the total amount. It was shown that 93% (14/15) of patients with metastases had a total score higher than 0, while 93% (14/15) of patients without metastases had a total score of zero or less than zero. The differences between the groups were statistically significant according to the two-sided Fisher test with a high level of confidence probability (p=0.000003) and the log-rank test (p=0.00004) when assessing non-metastatic survival by the Kaplan-Mayer method.Conclusion. Nineteen WNT signaling genes were identified. Copy number aberrations of these genes in combination with stemness gene amplifications in residual tumors were associated with metastasis. A new highly effective prognostic factor for breast cancer was identified. Введение. Изучена ассоциация с гематогенным метастазированием наличия 2 и более амплификаций генов стволовости и CNA (Copy Number Aberration) локусов генов WNT-сигнального пути в остаточной резидуальной опухоли молочной железы. Идентифицированы гены WNT-pathway, ассоциированные с метастазированием.Материал и методы. В исследование были включены 30 больных раком молочной железы, в резидуальной опухоли которых после неоадъювантной химиотерапии были 2 и более амплификации генов стволовости. У 15 из 30 больных развились гематогенные метастазы, они составили группу с метастазами, во вторую группу без метастазов вошли остальные 15 пациентов. ДНК опухоли была исследована при помощи микроматрицы CytoScanHD Array (Affymetrix, USA).Результаты. Путем вычитания частот амплификаций и делеций по 852 цитобендам между группами с метастазами и без метастазов был установлен 21 цитобенд с наибольшей разницей частот делеций и амплификаций. В них находятся 19 из 150 генов WNT (14 активаторов: SKP1, WNT8A, MAPK9, CCND3, FZD9, WNT8B, CCND1, PLCB2, PRKCB, FZD2, WNT3, WNT9B и 7 негативных регуляторов: GSK3B, APC, CSNK2B, SFRP5, BTRC, TCF7L2, CSNK2A2). Была разработана балльная система, при амплификации активаторов WNT-сигналинга или делеции негативных регуляторов к общей сумме баллов прибавлялся один балл, и, наоборот, при делеции активаторов WNT-сигналинга или амплификации негативных регуляторов от общей суммы отнимался один балл. Показано, что 93 % (14/15) больных с метастазами имеют суммарный балл больше 0, в то время как 93 % (14/15) больных без метастазов имеют суммарный балл, равный нулю или меньше нуля. Различия между группами статистически значимы по двустороннему критерию Фишера с высоким уровнем доверительной вероятности (р=0,000003) и по лог-ранговому тесту (р=0,00004) при оценке безметастатической выживаемости по методу Каплана – Майера.Заключение. Были идентифицированы 19 генов WNT-сигналинга, CNA которых в резидуальной опухоли, совместно с амплификациями генов стволовости ассоциированы с метастазированием и могут использоваться в качестве прогностического фактора.

Protons in near earth orbit

The proton spectrum in the kinetic energy range 0.1 to 200 GeV was measured by the Alpha Magnetic Spectrometer (AMS) during space shuttle flight STS-91 at an altitude of 380 km. Above the geomagnetic cutoff the observed spectrum is parameterized by a power law. Below the geomagnetic cutoff a substantial second spectrum was observed concentrated at equatorial latitudes with a flux ~ 70 m^-2 sec^-1 sr^-1. Most of these second spectrum protons follow a complicated trajectory and originate from a restricted geographic region.Comment: 19 pages, Latex, 7 .eps figure

Search for antihelium in cosmic rays

The Alpha Magnetic Spectrometer (AMS) was flown on the space shuttle Discovery during flight STS-91 in a 51.7 degree orbit at altitudes between 320 and 390 km. A total of 2.86 * 10^6 helium nuclei were observed in the rigidity range 1 to 140 GV. No antihelium nuclei were detected at any rigidity. An upper limit on the flux ratio of antihelium to helium of < 1.1 * 10^-6 is obtained.Comment: 18 pages, Latex, 9 .eps figure