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em Helda - Digital Repository of University of Helsinki


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The study is dedicated to the Russian poet and prose writer Anatolii Borisovich Mariengof (1897–1962). Mariengof – “the last dandy of the Republic” – was one of the leaders and main theoreticians in the poetic group of the Russian Imaginists. For his contemporaries, he was an Imaginist par excellence. His Imaginist principles – in theory and practice – are applied to the study of his first fictional novel, Cynics (1928), which served as an epilogue for his Imaginist period (1918–1928). The novel was not published in the Soviet Union until 1988. The method used in the study is a conceptual and literary historical reading, making use of the contemporary semiotic understanding of cultural mechanisms and of intertextual analysis. There are three main concepts used throughout the study: dandy, montage and catachresis. In the first chapter, the history, practice and theory of the Russian Imaginism are analyzed from the point of view of dandyism. The Imaginist theatricalisation of life is juxtaposed with the thematic analysis of their poetry, and Imaginist dandyism appears as a catachrestic category in culture. The second chapter examines the Imaginist poetic theory. It is discussed in the context of the montage principle, defining the post-revolutionary culture in Soviet Russia. The Imaginist montage can be divided into three main theoretical paradigms: S. Yesenin’s “technical montage” (reminiscent of Dadaist collage), V. Shershenevich’s “nominative montage” (catalogues of images) and Anatolii Mariengof’s “catachrestic montage”. The final chapter deals with Mariengof’s first fictional novel, Cynics. The study begins with the complex history of publication of the novel, as well as its relation to the Imaginist poetic principles and to the history of the poetic movement. Cynics is, essentially, an Imaginist montage novel. The fragmentary play of the fictional and the documentary material follows the Imaginist montage principle. The chapter concludes in a thematic analysis of the novel, concentrating on the description of the October Revolution in Cynics.

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Neurofibromatosis 2 (NF2) is an autosomal dominant disorder manifested by the formation of multiple benign tumors of the nervous system. Affected individuals typically develop bilateral vestibular schwannomas which lead to deafness and balance disorders. The syndrome is caused by inactivation of the NF2 tumor suppressor gene, and mutation or loss of the NF2 product, merlin, is sufficient for tumorigenesis in both hereditary and sporadic NF2-associated tumors. Merlin belongs to the band 4.1 superfamily of cytoskeletal proteins, which also contain the related ezrin, radixin, and moesin (ERM) proteins. The ERM members provide a link between the cell cytoskeleton and membrane by connecting membrane-associated proteins to actin filaments. By stabilizing complexes in the cell cortex, the ERMs modulate morphology, growth, and migration of cells. Despite their structural homology, overlapping subcellular distribution, direct molecular association, and partial overlap of molecular interactions, merlin and ezrin exert opposite effects on cell proliferation. Merlin suppresses cell proliferation, whereas ezrin expression is linked to oncogenic activity. We hypothesized that the regions which differ between the proteins might explain merlin s specificity as a tumor suppressor. We therefore analyzed the regions, which are most diverse between merlin and ezrin; the N-terminal tail and the C-terminus. To determine the properties of the C-terminal region, we studied the two most predominant merlin isoforms together with truncation variants similar to those found in patients. We also focused on the evolutionally conserved C-terminal residues, E545-E547, that harbor disease causing mutations in its corresponding DNA sequence. In addition to inhibiting cell proliferation, merlin regulates cytoskeletal organization. The morphogenic properties of merlin may play a role in tumor suppression, since patient-derived tumor cells demonstrate cytoskeletal abnormalities. We analyzed the mechanisms of merlin-induced extension formation and determined that the C-terminal region of amino acids 538-568 is particularly important for the morphogenic activity. We also characterized the role of C-terminal merlin residues in the regulation of proliferation, phosphorylation, and intramolecular associations. In contrast to previous reports, we demonstrated that both merlin isoforms are able to suppress cell proliferation, whereas C-terminally mutated merlin constructs showed reduced growth inhibition. Phosphorylation serves as a mechanism to regulate the tumor suppressive activity of merlin. The C-terminal serine 518 is phosphorylated in response to both p21-activated kinase (PAK) and protein kinase A (PKA), which inactivates the growth inhibitory function of merlin. However, at least three differentially phosphorylated forms of the protein exist. In this study we demonstrated that also the N-terminus of merlin is phosphorylated by AGC kinases, and that both PKA and Akt phosphorylate merlin at serine 10 (S10). We evaluated the impact of this N-terminal tail phosphorylation, and showed that the phosphorylation state of S10 is an important regulator of merlin s ability to modulate cytoskeletal organization but also regulates the stability of the protein. In summary, this study describes the functional effect of merlin specific regions. We demonstrate that both S10 in the N-terminal tail and residues E545-E547 in the C-terminus are essential for merlin activity and function.