A Regent and Her Court: Towards a Study of Maria Maddalena d'Austria's Patronage (FLORENCE 1621–28)

This essay outlines a longer research into cultural production during the Florentine regency of Maria Maddalena d'Austria and Cristina of Lorraine (1621–1628). It challenges widely held beliefs on patronage and on the climate prevailing at court in this period. Specifically it analyzes a stage fragment and two short poems by Ottavio Rinuccini in order to provide an indicative case study of the project at large

A New Type of Signal Peptidase Cleavage Site Identified in an RNA Virus Polyprotein*

Pestiviruses, a group of enveloped positive strand RNA viruses belonging to the family Flaviviridae, express their genes via a polyprotein that is subsequently processed by proteases. The structural protein region contains typical signal peptidase cleavage sites. Only the site at the C terminus of the glycoprotein Erns is different because it does not contain a hydrophobic transmembrane region but an amphipathic helix functioning as the Erns membrane anchor. Despite the absence of a hydrophobic region, the site between the C terminus of Erns and E1, the protein located downstream in the polyprotein, is cleaved by signal peptidase, as demonstrated by mutagenesis and inhibitor studies. Thus, ErnsE1 is processed at a novel type of signal peptidase cleavage site showing a different membrane topology. Prevention of glycosylation or introduction of mutations into the C-terminal region of Erns severely impairs processing, presumably by preventing proper membrane interaction or disturbing a conformation critical for the protein to be accepted as a substrate by signal peptidase