Understanding actor roles in sustainability initiatives: an exploratory study in five European countries

Several strands of literature have developed around the ambition to influence or bring about transitions toward greater sustainability. In this context researchers have come to be interested in the types of actors involved in sustainability transitions and the roles these actors play. However, there is a lack of clear definitions of actors, and their roles. Our research takes an exploratory approach and is designed to describe and analyse the actors concerned and to identify their roles in sustainability initiatives. Our aim in doing so is to contribute to the body of scientific knowledge on transitions and to provide sustainability initiatives themselves with helpful information. Data were collected using the Net-Map tool, a well-established method in actor and stakeholder analysis. In our results we identify and define six actor roles: catalysts, opponents, intermediaries, frontrunners, drivers and visionaries. In the literature, particular roles are connected to common actor categories (civil society, governmental actors, private sector, etc.). Our results imply that sustainability initiatives are neither necessarily hindered by the absence of certain actors, nor are they hindered per se by the presence of an actor - rather, a broad mix seems to be helpful

Integration of the β-Catenin-Dependent Wnt Pathway with Integrin Signaling through the Adaptor Molecule Grb2

THE COMPLEXITY OF WNT SIGNALING LIKELY STEMS FROM TWO SOURCES: multiple pathways emanating from frizzled receptors in response to wnt binding, and modulation of those pathways and target gene responsiveness by context-dependent signals downstream of growth factor and matrix receptors. Both rac1 and c-jun have recently been implicated in wnt signaling, however their upstream activators have not been identified.Here we identify the adapter protein Grb2, which is itself an integrator of multiple signaling pathways, as a modifier of beta-catenin-dependent wnt signaling. Grb2 synergizes with wnt3A, constitutively active (CA) LRP6, Dvl2 or CA-beta-catenin to drive a LEF/TCF-responsive reporter, and dominant negative (DN) Grb2 or siRNA to Grb2 block wnt3A-mediated reporter activity. MMP9 is a target of beta-catenin-dependent wnt signaling, and an MMP9 promoter reporter is also responsive to signals downstream of Grb2. Both a jnk inhibitor and DN-c-jun block transcriptional activation downstream of Dvl2 and Grb2, as does DN-rac1. Integrin ligation by collagen also synergizes with wnt signaling as does overexpression of Focal Adhesion Kinase (FAK), and this is blocked by DN-Grb2.These data suggest that integrin ligation and FAK activation synergize with wnt signaling through a Grb2-rac-jnk-c-jun pathway, providing a context-dependent mechanism for modulation of wnt signaling