The Brain-Specific Beta4 Subunit Downregulates BK Channel Cell Surface Expression

The large-conductance K+ channel (BK channel) can control neural excitability, and enhanced channel currents facilitate high firing rates in cortical neurons. The brain-specific auxiliary subunit β4 alters channel Ca++- and voltage-sensitivity, and β4 knock-out animals exhibit spontaneous seizures. Here we investigate β4's effect on BK channel trafficking to the plasma membrane. Using a novel genetic tag to track the cellular location of the pore-forming BKα subunit in living cells, we find that β4 expression profoundly reduces surface localization of BK channels via a C-terminal ER retention sequence. In hippocampal CA3 neurons from C57BL/6 mice with endogenously high β4 expression, whole-cell BK channel currents display none of the characteristic properties of BKα+β4 channels observed in heterologous cells. Finally, β4 knock-out animals exhibit a 2.5-fold increase in whole-cell BK channel current, indicating that β4 also regulates current magnitude in vivo. Thus, we propose that a major function of the brain-specific β4 subunit in CA3 neurons is control of surface trafficking

Home country supportiveness/unfavorableness and outward foreign direct investment from China

What drives the outward foreign direct investments (OFDIs) by emerging market firms (EMFs)? Drawing on a strategy tripod framework, this article proposes a theoretical model to predict OFDI by EMFs from China. Specifically, we use institution- and industry-based views to examine two facets of home country environment, namely the supportiveness from home government and unfavorableness from home industry, as important determinants of OFDI, and compare the relative strength of these effects. Further, we use resource-based view to argue that the effect of the home country environment is contingent on the international experience portfolios of EMFs

Angel investor's selection criteria: a comparative institutional perspective

Despite the important role of angel investors as critical financial providers for new ventures, little is known regarding how institutions make their investment decisions. While angels make decisions based on selection criteria during the first stage, they are also embedded within and affected by different institutional settings and as a result weight these criteria differently than other investors. We compare angel investors' selection criteria in China and Denmark using the comparative institutional perspective. We use a policy capturing approach and hierarchy linear modeling, revealing that since Chinese angels are embedded within relationship-based institutional settings they tend to reply more on strong ties such as family and friends in management team, as well as weighting risks less compared to Danish angels operating within more rule-based institutional contexts

Pan-cancer analysis of whole genomes

Cancer is driven by genetic change, and the advent of massively parallel sequencing has enabled systematic documentation of this variation at the whole-genome scale(1-3). Here we report the integrative analysis of 2,658 whole-cancer genomes and their matching normal tissues across 38 tumour types from the Pan-Cancer Analysis of Whole Genomes (PCAWG) Consortium of the International Cancer Genome Consortium (ICGC) and The Cancer Genome Atlas (TCGA). We describe the generation of the PCAWG resource, facilitated by international data sharing using compute clouds. On average, cancer genomes contained 4-5 driver mutations when combining coding and non-coding genomic elements; however, in around 5% of cases no drivers were identified, suggesting that cancer driver discovery is not yet complete. Chromothripsis, in which many clustered structural variants arise in a single catastrophic event, is frequently an early event in tumour evolution; in acral melanoma, for example, these events precede most somatic point mutations and affect several cancer-associated genes simultaneously. Cancers with abnormal telomere maintenance often originate from tissues with low replicative activity and show several mechanisms of preventing telomere attrition to critical levels. Common and rare germline variants affect patterns of somatic mutation, including point mutations, structural variants and somatic retrotransposition. A collection of papers from the PCAWG Consortium describes non-coding mutations that drive cancer beyond those in the TERT promoter(4); identifies new signatures of mutational processes that cause base substitutions, small insertions and deletions and structural variation(5,6); analyses timings and patterns of tumour evolution(7); describes the diverse transcriptional consequences of somatic mutation on splicing, expression levels, fusion genes and promoter activity(8,9); and evaluates a range of more-specialized features of cancer genomes(8,10-18).Peer reviewe

STUDIES ON THE NATURE OF SMPI AND PROMOTER ACTION IN Rh-Nb2O5/SiO2 CATALYSTS FOR SYNGAS CONVERSION TO ETHANOL

Syngas conversion to ethanol by supported catalysts is an important progress in C, chemistry. It has been reported by our laboratory that Rh sites and niobia sites coexisted on Rh-Nb(2)O(5)/SiO(2) catalysts as detected by means of reaction chemistry involving the catalytic aromatization and polymerization of acetylene on such catalysts. This paper reports a further study consisting of the following three parts, (1) The probable existence of Nb-H bonds on hydrogen reduced Rh-Nb(2)O(5)/SiO(2) was deduced from the catalytic activity toward polymerization of acetylene to polyacetylene and the loss of catalytic activity toward cyclotrimerization of acetylene of such catalysts. ( 2) The FUR spectra of the above mentioned catalysts were studied. The peak at 1740 cm(-1) (vw) may be assigned to that at 1560 cm(-1) (m, broad) to while that at 1269 cm-1 (s) most probably to a bridging species, [GRAPHICS] (3) The existence of Rh(0), Rh(1), Nb(v), Nb(IV) and two types of carbonoceous deposits on syngas treated Rh-Nb(2)O(5)/SiO(2), catalysts was detected by XPS, A model of active center, A (cf. Fig.3) (abbr. B), formed by partial reduction of niobia through hydrogen spillover and "wetting" or partial coating of the surfaces of rhodium particles (Rh Rh ) by the partially reduced niobia, has been proposed. By analogy with known organometallic chemistry, the major reaction pathway might involve migratory insertion of chemisorbed species C to form E, hydrogenation to F cis-coupling with (CO) under bar to form coordinated ketene, and further hydrogenation to ethanol or aldehyde with simultaneous regeneration of the active site by hydrogenation and elimination of H(2)O(3) while r_ethane CH , was produced by hydrogenation of the coordinated carbene (CH(3)) under bar, in a secondary reaction pathway. The true nature of SMPI in the present system been discussed