Extracellular disulfide exchange and the regulation of cellular function

An emerging concept is that disulfide bonds can act as a dynamic scaffold to present mature proteins in different conformational and functional states on the cell surface. Two examples are the conversion of the receptor, integrin a alpha(IIb)beta(3), from a low affinity to a high affinity state, and the interaction of CD4 receptor with the HIV-1 envelope glycoprotein gp120 to promote virus-cell fusion. In both of these cases there is a remodeling of the protein disulfide bonding pattern. The formation and rearrangement of disulfide bonds is modulated by a family of enzymes known as the thiol isomerases, which include protein disulfide isomerase (PDI), ERp5, ERp57, and ERp72. While these enzymes were reported originally to be restricted in location to the endoplasmic reticulum, in some cells thiol isomerases are found on the cell surface. This may indicate a wider role for these enzymes in cell function. In platelets it has been shown that reagents that react with cell surface sulfhydryl groups are capable of blocking a number of functional responses, including integrin-mediated aggregation, adhesion, and granule secretion. Furthermore, the use of function blocking antibodies to either PDI or ERp5 causes inhibition of these functional responses. This review summarizes current knowledge of the extracellular regulation of disulfide exchange and the implications of this in the regulation of cell function.

The effects of government deficit on equilibrium real exchange rates and stock prices

This paper studies the effect of government deficits on equilibrium real exchange rates and stock prices. The theoretical part modifies a two-country cash-in-advance model like used in Lucas(1982) and Sargent(1987) in order to accommodate an exchange rate market and a government that pursues fiscal and monetary policy targets. The implied result is that unanticipated shocks in government deficits raise expectations of both taxes and inflation and, therefore, are associated with real exchange rate devaluations and lower stock prices. This finding is strongly supported by empirical evidence for a group of 19 countries, representing 76% of world production

Trade regulation of exchange rates

O presente estudo busca analisar o quadro regulatório internacional referente a medidas cambiais que trazem impactos no comércio. O artigo pretende explorar como a questão do câmbio se relaciona à OMC e afeta seus instrumentos e princípios para, em seguida, buscar dispositivos nos Acordos da OMC que poderiam ser aplicados à questão cambial a fim de reequilibrar os impactos causados pelos desalinhamentos cambiais no comércio internacional

GATS and the Regulation of Trade in Services

This collection of essays takes stock of the key challenges that have arisen since the entry into force of the General Agreement on Trade in Services in the mid-1990s and situates them in the context of the WTO's Doha Development Agenda and the proliferation of preferential agreements addressing services today. The multidisciplinary approach provides an opportunity for many of the world's leading experts and a number of new analytical voices to exchange ideas on the future of services trade and regulation. Cosmopolitan approaches to the treatment of labour mobility, the shape of services trade disciplines in the digital age and pro-competitive regulation in air transport are explored with a view to helping readers gain a better understanding of the forces shaping the changes. An essential read for all those concerned with the evolution of the rules-based trading system and its impact on the service economy.