CD148 is a membrane protein tyrosine phosphatase present in all hematopoietic lineages and is involved in signal transduction on lymphocytes

Producción CientíficaEvidence is presented showing that a protein tyrosine phosphatase different from CD45 is present on the membrane of human hematopoietic cells. The molecule recognized by the monoclonal antibody 143-41, which has been classified as CD148 in the VI International Workshop on Leukocyte Differentiation Antigens, was immunopurified and sequenced. The sequence obtained from N-terminus as well as from two different CNBr-digested peptides showed a close identity with a previously described tyrosine phosphatase named HPTP-eta/DEP-1. CD148 is present on all hematopoietic lineages, being expressed with higher intensity on granulocytes than on monocytes and lymphocytes. Interestingly, whereas it is clearly present on peripheral blood lymphocytes, it is poorly expressed on different lymphoid cell lines of T and B origin. When this protein tyrosine phosphatase was cocrosslinked with CD3, an inhibition of the normally observed calcium mobilization was observed. This inhibition correlates with a decrease in phospholipase C-gamma (PLC-gamma) phosphorylation and is similar to the one observed with CD45. In addition, it is shown that the crosslinking of the CD148 alone is also able to induce an increase in [Ca2+]i. This increase is abolished in the presence of genistein and by cocrosslinking with CD45. These data, together with the induction of tyrosine phosphorylation on several substrates, including PLC-gamma, after CD148 crosslinking, suggest the involvement of a tyrosine kinase-based signaling pathway in this process. In conclusion, the data presented show that CD148 corresponds to a previously described protein tyrosine phosphatase HPTP-eta/DEP-1 and that this molecule is involved in signal transduction in lymphocytes

Using choir conducting to improve leadership practice

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Imagining a sustainable future: Eschatology, Bateson’s ecology of mind and arts-based practice

In the face of multiple ecological crises, critical management studies (CMS) scholars have focused on exposing how mainstream organizational discourses refute the need for fundamental shifts in society to bring about a sustainable future, emphasizing instead incremental improvement underpinned by a business case approach based on eco-efficiency. While some CMS researchers go on to stress the necessity of fundamental paradigm shifts, even this more radical discourse by and large fails to provide an imaginative, hopeful vision for organizational practice and theorizing in service of ecological sustainability. We propose that an ‘eschatological imagination’ (Alison, 2010; Shields, 2008) would add a much-needed action- and future-oriented dimension to the CMS research agenda on sustainability. Eschatology focuses on the coming of a new era through a concern with the creative overcoming of hegemonic stories through the enactment of counter-stories. We present three frame-breaking qualities of eschatology: first, a ‘rhetoric of hope’; second, the ‘aesthetic harmonization of contrasts’; and third, ‘possibilities for flexible imitation’. Drawing on the work of Gregory Bateson as an illustrative counter-story, we explain how an eschatological framework enables a critical yet imaginative and future-oriented engagement with ecological challenges. Finally, we offer a tentative example of such experimentation: the work of an activist eco-poet which begins to show how defamiliarizing narratives demonstrating these qualities can inform research practice