Immunological characterization of chromogranins A and B and secretogranin II in the bovine pancreatic islet

Antisera against chromogranin A and B and secretogranin II were used for analysing the bovine pancreas by immunoblotting and immunohistochemistry. All three antigens were found in extracts of fetal pancreas by one dimensional immunoblotting. A comparison with the soluble proteins of chromaffin granules revealed that in adrenal medulla and in pancreas antigens which migrated identically in electrophoresis were present. In immunohistochemistry, chromogranin A was found in all pancreatic endocrine cell types with the exception of most pancreatic polypeptide-(PP-) producing cells. For chromogranin B, only a faint immunostaining was obtained. For secretorgranin II, A-and B-cells were faintly positive, whereas the majority of PP-cells exhibited a strong immunostaining for this antigen. These results establish that chromogranins A and B and secretogranin II are present in the endocrine pancreas, but that they exhibit a distinct cellular localization

Cornish identities and migration: a multi-scalar approach

The definitive version is available at www.blackwell-synergy.com. 24 month embargo by the publisher. Article will be released July 2009.In this article we argue that theories of transnationalism have value in exploring the historical context of migration and that historical contexts help to shape such theoretical conceptualizations. Historians of migration have now begun to engage more directly with the literature of transnationalism, focusing on the networks that linked settler and home communities. Here we add to this by examining a nineteenth-century migrant community from a British region through the lens of transnationalism, applying the concept to the case of the Cornish, whose economic specialization produced culturally distinct Cornish communities on the mining frontiers of North America, Australia and South Africa. In doing so, we bring together the issues of scale and time. We review the multiple levels of the Cornish transnational space of the late nineteenth century, which exhibited aspects of both core transnationalism and translocalism. This waned, but in the later twentieth century, a renewed interest in a transnational Cornish identity re-emerged, articulating with changing identity claims in Cornwall itself. To capture better the experience of the Cornish over these two very different phases of transnationalism we identify another subset of transnationalism - that of transregionalism.Leverhulme Trus

L-Ilf3 and L-NF90 Traffic to the Nucleolus Granular Component: Alternatively-Spliced Exon 3 Encodes a Nucleolar Localization Motif

Ilf3 and NF90, two proteins containing double-stranded RNA-binding domains, are generated by alternative splicing and involved in several functions. Their heterogeneity results from posttranscriptional and posttranslational modifications. Alternative splicing of exon 3, coding for a 13 aa N-terminal motif, generates for each protein a long and short isoforms. Subcellular fractionation and localization of recombinant proteins showed that this motif acts as a nucleolar localization signal. Deletion and substitution mutants identified four arginines, essential for nucleolar targeting, and three histidines to stabilize the proteins within the nucleolus. The short isoforms are never found in the nucleoli, whereas the long isoforms are present in the nucleoplasm and the nucleoli. For Ilf3, only the posttranslationally-unmodified long isoform is nucleolar, suggesting that this nucleolar targeting is abrogated by posttranslational modifications. Confocal microscopy and FRAP experiments have shown that the long Ilf3 isoform localizes to the granular component of the nucleolus, and that L-Ilf3 and L-NF90 exchange rapidly between nucleoli. The presence of this 13 aminoacid motif, combined with posttranslational modifications, is responsible for the differences in Ilf3 and NF90 isoforms subcellular localizations. The protein polymorphism of Ilf3/NF90 and the various subcellular localizations of their isoforms may partially explain the various functions previously reported for these proteins