Molecular Landscape of the Ribosome Pre-initiation Complex during mRNA Scanning: Structural Role for eIF3c and Its Control by eIF5

Citation: Obayashi, E., Luna, R. E., Nagata, T., Martin-Marcos, P., Hiraishi, H., Singh, C. R., . . . Asano, K. (2017). Molecular Landscape of the Ribosome Pre-initiation Complex during mRNA Scanning: Structural Role for eIF3c and Its Control by eIF5. Cell Reports, 18(11), 2651-2663. doi:10.1016/j.celrep.2017.02.052During eukaryotic translation initiation, eIF3 binds the solvent-accessible side of the 40S ribosome and recruits the gate-keeper protein eIF1 and eIF5 to the decoding center. This is largely mediated by the N-terminal domain (NTD) of eIF3c, which can be divided into three parts: 3c0, 3c1, and 3c2. The N-terminal part, 3c0, binds eIF5 strongly but only weakly to the ribosome-binding surface of eIF1, whereas 3c1 and 3c2 form a stoichiometric complex with eIF1. 3c1 contacts eIF1 through Arg-53 and Leu-96, while 3c2 faces 40S protein uS15/S13, to anchor eIF1 to the scanning pre-initiation complex (PIC). We propose that the 3c0:eIF1 interaction diminishes eIF1 binding to the 40S, whereas 3c0:eIF5 interaction stabilizes the scanning PIC by precluding this inhibitory interaction. Upon start codon recognition, interactions involving eIF5, and ultimately 3c0:eIF1 association, facilitate eIF1 release. Our results reveal intricate molecular interactions within the PIC, programmed for rapid scanning-arrest at the start codon

The Liberal Playground: Susan Isaacs, Psychoanalysis and Progressive Education in the Interwar Era

The Cambridge Malting House, an experimental school, serves here as a case study for investigating the tensions within 1920s liberal elites between their desire to abandon some Victorian and Edwardian sets of values in favour of more democratic ones, and at the same time their insistence on preserving themselves as an integral part of the English upper class. Susan Isaacs, the manager of the Malting House, provided the parents – some of whom were the most famous scientists and intellectuals of their age – with an opportunity to fulfil their ‘fantasy’ of bringing up children in total freedom. In retrospect, however, she deeply criticized those from their milieu for not fully understanding the real socio-cultural implications of their ideological decision to make independence and freedom the core values in their children’s education. Thus, 1920s progressive education is a paradigmatic case study of the cultural and ideological inner contradictions within liberal thought in the interwar era. The article also shows how psychoanalysis – which attracted many progressive educators – played a crucial role in providing liberals of all sorts with a new language to articulate their political visions, but, at the same time, explored the limits of the liberal discourse as a whole

The Science Performance of JWST as Characterized in Commissioning

This paper characterizes the actual science performance of the James Webb Space Telescope (JWST), as determined from the six month commissioning period. We summarize the performance of the spacecraft, telescope, science instruments, and ground system, with an emphasis on differences from pre-launch expectations. Commissioning has made clear that JWST is fully capable of achieving the discoveries for which it was built. Moreover, almost across the board, the science performance of JWST is better than expected; in most cases, JWST will go deeper faster than expected. The telescope and instrument suite have demonstrated the sensitivity, stability, image quality, and spectral range that are necessary to transform our understanding of the cosmos through observations spanning from near-earth asteroids to the most distant galaxies

Towards an ergonomic linguistics: Application to the design of controlled natural languages

International audienceThis article proposes to define a "new" discipline within applied linguistics: ergonomic linguistics. The article addresses issues concerning language use within organisations, focusing on human-oriented Controlled Natural Languages (CNLs) whose role is to limit the problems encountered with natural language, in professional contexts in particular. An ergonomic linguistics approach involves first taking into account real linguistic productions and analysing them with corpus linguistics methods, and then evaluating the efficacy of linguists' recommendations using cognitive evaluation or acceptance tests. Two projects concerning human-oriented CNLs that adopt an ergonomic linguistics approach are presented, the first in the space domain and the second in aeronautics