CTIF is involved in mRNA export in human cells

In eukaryotic cells, translation of messenger RNA (mRNA) can be initiated either on transcripts associated with the cap-binding complex (CBC; consisting of CBP80 and CBP20) or on transcripts with the eukaryotic translation initiation factor (eIF) 4E bound to the cap. Together with eIF4G and eIF4A, eIF4E forms the eIF4F-complex, which mediates translation initiation during the bulk of cellular protein synthesis. Functionally substituting for eIF4G, the CBP80/20-dependent translation initiation factor (CTIF) has been reported to be part of the CBC-dependent translation initiation complex 1,2. CTIF consists of a N-terminal CBP80-binding domain and a conserved C-terminal MIF4G domain 1. This MIF4G domain has been shown to mediate the interaction between CTIF and different factors such as eIF3g and the stem-loop binding protein (SLBP) 2,3. Here we provide evidence that CTIF, besides its function in translation initiation, is also involved in mRNA translocation from the nucleus to the cytoplasm, possibly through a direct interaction with the nuclear export factor NFX1/TAP. Taken together our results suggest that CTIF can function as a platform that interacts with proteins involved in different steps of the mRNA metabolism.

CTIF is involved in mRNA export in human cells

In eukaryotic cells translation initiation of messenger RNA (mRNA) transcripts can be initiated either by the cap-binding complex (CBC) consisting of CBP80 and CBP20, or by the eukaryotic translation initiation factor (eIF) 4E. Together with eIF4G and eIF4A, eIF4E forms the eIF4F-complex, which mediates initiation of the bulk of cellular translation. Analogous to eIF4G, the CBP80/20-dependent translation initiation factor (CTIF) has been reported to be part of the CBC-dependent translation initiation complex. CTIF consists of a N-terminal CBP80-binding domain and a conserved C-terminal MIF4G domain. This MIF4G domain has been shown to mediate the interaction between CTIF and different factors such as eIF3g and the stem-loop binding protein (SLBP). Here we show data indicating that CTIF, besides its function in translation initiation, is involved in mRNA translocation from the nucleus to the cytoplasm, possibly through a direct interaction with the nuclear export factor NFX1/TAP. Taken together our results suggest that CTIF can function as a platform that interacts with proteins involved in different steps of mRNA metabolism.

CTIF is involved in mRNA export in human cells

In eukaryotic cells translation initiation of messenger RNA (mRNA) transcripts can be initiated either by the cap-binding complex (CBC) consisting of CBP80 and CBP20, or by the eukaryotic translation initiation factor (eIF) 4E. Together with eIF4G and eIF4A, eIF4E forms the eIF4F-complex, which mediates translation initiation during the bulk of cellular protein synthesis [1,2]. Functionally analogous to eIF4G, the CBP80/20-dependent translation initiation factor (CTIF) has been reported to be part of the CBC-dependent translation initiation complex [3,4]. CTIF consists of a N-terminal CBP80-binding domain and a conserved C-terminal MIF4G domain [3]. This MIF4G domain has been shown to mediate the interaction between CTIF and different factors such as eIF3g and the stem-loop binding protein (SLBP) [4,5]. Here we show data indicating that CTIF, besides its function in translation initiation, is involved in mRNA translocation from the nucleus to the cytoplasm, possibly through a direct interaction with the nuclear export factor NFX1/TAP. Taken together our results suggest that CTIF can function as a platform that interacts with proteins involved in different steps of the mRNA metabolism. [1] Haghighat A. and Sonenberg N. (1997) JBC 272:21677-21680 [2] Gross J.D. et al. (2003) Cell 115:739-750 [3] Kim K.M. et al. (2009) Genes Dev 23:2033-2045 [4] Choe J. et al. (2012) JBC 287:18500-18509 [5] Choe J. et al. (2013) NAR 41:1307-1318

NMD3 regulates both mRNA and rRNA nuclear export in African trypanosomes via an XPOI-linked pathway

Trypanosomes mostly regulate gene expression through post-transcriptional mechanisms, particularly mRNA stability. However, much mRNA degradation is cytoplasmic such that mRNA nuclear export must represent an important level of regulation. Ribosomal RNAs must also be exported from the nucleus and the trypanosome orthologue of NMD3 has been confirmed to be involved in rRNA processing and export, matching its function in other organisms. Surprisingly, we found that TbNMD3 depletion also generates mRNA accumulation of procyclin-associated genes (PAGs), these being co-transcribed by RNA polymerase I with the procyclin surface antigen genes expressed on trypanosome insect forms. By whole transcriptome RNA-seq analysis of TbNMD3-depleted cells we confirm the regulation of the PAG transcripts by TbNMD3 and using reporter constructs reveal that PAG1 regulation is mediated by its 5'UTR. Dissection of the mechanism of regulation demonstrates that it is not dependent upon translational inhibition mediated by TbNMD3 depletion nor enhanced transcription. However, depletion of the nuclear export factors XPO1 or MEX67 recapitulates the effects of TbNMD3 depletion on PAG mRNAs and mRNAs accumulated in the nucleus of TbNMD3-depleted cells. These results invoke a novel RNA regulatory mechanism involving the NMD3-dependent nuclear export of mRNA cargos, suggesting a shared platform for mRNA and rRNA export.

Clothing Export from sub-Saharan Africa : Impact on Poverty and Potential for Growth

Increases in clothing exports after 2000 signaled the first incidence of large-scale manufacturing exports from sub-Saharan Africa. Using firm-level information, this paper explores the potential of clothing exports for poverty reduction and further growth as seen in other low income countries. It shows that the garment exporting industries in Kenya and Madagascar have contributed poverty reduction in the short term by providing mass employment for female and less educated workers with wages beyond the poverty line. However, the long-term impact is not certain. High production costs and limited development of local firms weaken potential for further growth in the competitive world market. Upgrading of the market and improvement of efficiency are required to remain competitive for African industries, and governmental support for local participation are needed to facilitate technology transfer.

FDI, trade and growth, a causal link?

. FDI, Trade and Growth, a Causal Link? (RP0710) Prof Nigel DRIFFIELD Dr Rakesh BISSOONDEEAL Mayang Pramadhani Non-technical Summary This paper explores the relationship between imports, exports, foreign direct investment and growth. For some time there has been a good deal of debate whether trade and foreign direct investment) FDI are substitutes and complements, with the existing literature generating some rather contradictory findings. We show, for Indonesia that inward FDI and both imports and exports are complementary, and further that FDI causes an increase in trade. This is of particular interest for a country such as Indonesia, that has attracted a high proportion of export-orientated inward investment. This, theoretically at least is associated with an increase in imports, in the form of capital goods and components, but a reduction in imports. We show that the previous literature that fails to find such a relationship does so because both trade and FDI are associated with growth, and previous work ignores these growth effects when seeking to isolate the relationship between trade and FDI.

Determinants and impacts of inward FDI in Japan

The research consists of three empirical studies. The first examines how source country characteristics affect the aggregate FDI inflows in the Japanese economy during the period of 1989-2002. Our results demonstrate that the stable investment climate of the home country is an essential factor indicating FDI inflows to Japan. By contrast, the export performance of the source country is negatively correlated with FDI inflows, indicating that international trade and FDI are substitutes. The second study identifies the determinants of foreign penetration across Japanese manufacturing sectors at the three-digit level during the period of 1997-2003. More importantly, this study examines the moderating effects of keiretsu affiliations on the relationship between various sectoral characteristics and foreign participation. The evidence of both horizontal and vertical keiretsu impacts on foreign penetration depends on not only different proxy measures used for inward FDI, but also on the level of technological sophistication in given sectors. In general, our results demonstrate that horizontally linked keiretsu are positively associated with foreign productions in knowledge-intensive sectors. By contrast, this effect becomes a significant entry barrier to foreign employment in low-tech sectors. The final study evaluates the impacts of a foreign presence on the productivity of Japanese manufacturing firms over the period of 1997-2003. Our results suggest that spillover effects largely differ according to the level of absorptive capacity of indigenous firms.

New Library-curated Faculty Profile Platform Launches Through bepress

As faculty needs evolve and become increasingly digital, libraries are feeling the pressure to provide relevant new services. At the same time, faculty members are struggling to create and maintain their professional reputations online. We at bepress are happy to announce the new SelectedWorks, the fully hosted, library-curated faculty profile platform that positions the library to better support faculty as well as the institution at large. Beverly Lysobey, Digital Commons and Resource Management Librarian, at Sacred Heart University, says: “Both faculty and administration have been impressed with the services we provide through SelectedWorks; we’re able to show how much our faculty really publishes, and it’s great for professors to get that recognition. We’ve had several faculty members approach us for help making sure their record was complete when they were up for tenure, and we’ve even found articles that authors themselves no longer had access to.” With consistent, organized, institution-branded profiles, SelectedWorks increases campus-wide exposure and supports the research mission of the university. As the only profile platform integrated with the fully hosted Digital Commons suite of publishing and repository services, it also ensures that the institution retains management of its content. Powerful integration with the Digital Commons platform lets the home institution more fully capture the range of scholarship produced on campus, and hosted services facilitate resource consolidation and reduces strain on IT. The new SelectedWorks features a modern, streamlined design that provides compelling display options for the full range of faculty work. It beautifully showcases streaming media, images, data, teaching materials, books – any type of content that researchers now produce as part of their scholarship. Detailed analytics tools let authors and librarians measure global readership and track impact for a variety of campus stakeholders: authors can see the universities, agencies, and businesses that are reading their work, and can easily export reports to use in tenure and promotion dossiers. Janelle Wertzbeger, Assistant Dean and Director of Scholarly Communications at Gettysburg College’s Musselman Library, says, “The new author dashboard maps and enhanced readership are SO GOOD. Every professor up for promotion & tenure should use them!” And of course, SelectedWorks is fully backed by the continual efforts of the bepress development team to provide maximum discoverability to search engines, increasing impact for faculty and institutions alike: Reverend Edward R. Udovic, Vice President for Teaching and Learning Resources at DePaul University, says, “In the last several months downloads of my scholarship from my [SelectedWorks] site have far surpassed the total distribution of all my work in the previous twenty five years.”

Geomorphology and sedimentology of a modern isolated carbonate platform: The glorieuses archipelago, SW Indian Ocean

The study of modern carbonate systems is commonly helps in improving facies interpretation in fossil reefs and in providing analogues of sediment distribution depending on the specific platform configuration (i.e. rimmed shelves and isolated carbonate platforms). This paper deals with a geomorphological and sedimentological study of the Glorieuses Archipelago, an isolated carbonate platform located between the northern tip of Madagascar and Mayotte. The dataset consists of Digital Terrain Model, satellite imagery, and box-sediment samples. Analyses of grain-size and composition of carbonate grains are used to characterize the distribution and heterogeneity of sediment accumulated on the isolated platform. Main results show that the Glorieuses Archipelago is organized in distinctive morphological units, including a reef flat developed along the windward side, an apron, and a semi-enclosed (< 12 m water depth) to open lagoon (> 12 m and up to 15 m water depth). The lack of carbonate mud in sediments deposited on the archipelago can be explained by the direct connection between the lagoon and the open ocean. The main carbonate grains include Halimeda segments, coral fragments, large benthic foraminifers, red algae, and molluscs. According to the shape and the position of intertidal sandwaves, the current arrangement of moderately sorted fine to medium sands appears to be strongly influenced by tidal currents. The in-situ sediment production, accumulation and transport on the platform finally contribute to carbonate sand export to distinct deep marine areas depending on wind regimes and currents.