Caspase cleavage of the Golgi stacking factor GRASP65 is required for Fas/CD95-mediated apoptosis

GRASP65 (Golgi reassembly and stacking protein of 65 KDa) is a cis-Golgi protein with roles in Golgi structure, membrane trafficking and cell signalling. It is cleaved by caspase-3 early in apoptosis, promoting Golgi fragmentation. We now show that cleavage is needed for Fas-mediated apoptosis: expression of caspase-resistant GRASP65 protects cells, whereas expression of membrane proximal caspase-cleaved GRASP65 fragments dramatically sensitises cells. GRASP65 coordinates passage through the Golgi apparatus of proteins containing C-terminal hydrophobic motifs, via its tandem PDZ type ‘GRASP' domains. Fas/CD95 contains a C-terminal leucine–valine pairing so its trafficking might be coordinated by GRASP65. Mutagenesis of the Fas/CD95 LV motif reduces the number of cells with Golgi-associated Fas/CD95, and generates a receptor that is more effective at inducing apoptosis; however, siRNA-mediated silencing or expression of mutant GRASP65 constructs do not alter the steady state distribution of Fas/CD95. We also find no evidence for a GRASP65–Fas/CD95 interaction at the molecular level. Instead, we find that the C-terminal fragments of GRASP65 produced following caspase cleavage are targeted to mitochondria, and ectopic expression of these sensitises HeLa cells to Fas ligand. Our data suggest that GRASP65 cleavage promotes Fas/CD95-mediated apoptosis via release of C-terminal fragments that act at the mitochondria, and we identify Bcl-XL as a candidate apoptotic binding partner for GRASP65

Conceptualising and Connecting Francophone Perspectives on Learning Through and for Work

This chapter offers an overview of the field of Francophone research on learning through work and is intended as a platform for presenting a delineation of this field. More specifically, the chapter presents a range of research traditions that have secured important places within the French-speaking research community, as illustrated in the chapters collected in the book. This overview aims at explaining the disciplinary background underlying these traditions, identifying key premises and concepts, and specific research and training methods that have emerged in that particular context. The chapter also attempts to illuminate the specific conceptions of learning these traditions are built on and have contributed to promote. To achieve that outcome, three research traditions are described, in relation to their historical and cultural backgrounds, and key ideas and methodological focuses. The first of these three traditions comprises what is referred to Francophone ergonomics and the epistemology of so-called "work analysis". The historical and disciplinary origins of emergence of the Francophone tradition of ergonomics are presented, along with its central concepts, contributions to methods and applications in the field of vocational and professional training. Second, a focus is placed on the tradition of language use in relation to work, training and learning. These issues have acquired considerable visibility within Francophone research and have developed into a specific research tradition. An overview of the main research topics that have emerged within this tradition and key contributions to vocational and professional training issues is presented below. The third tradition is that referring to learning in connection with specific organisational contexts. Here, the social dimensions of learning are foregrounded and contributions from Francophone researchers are illustrated, and their alignment with other research traditions, and particularly those widely disseminated in the Anglophone world. The final section of the chapter draws together a range of ideas which have emerged beyond and across these specific research traditions, and that can be seen as having played an influencing role on the ways questions related with learning through and for work have been addressed in the Francophone world.No Full Tex