Signaling in Anergy: from Fyn to Ras and beyond

在外周t细胞中，与鞘糖脂富集微域（PAG）相关的磷酸化蛋白似乎通过将c端src激酶（Csk）募集到质膜上，作为细胞激活的负调节因子发挥作用。通过其与PAG的关联，Csk能够抑制膜相关src激酶p56lck和p59fyn的活性。激活后，PAG被一种未知的磷酸酶去磷酸化，它与Csk的关联丢失，允许随后的src激酶激活和信号传导的诱导。该项目的目的是确定负责这种活性的磷酸酶，因为它是调节src激酶活性的潜在靶标，从而调节t细胞的活性。PAG在t细胞发育、诱导能量、粘附和迁移中的作用也将被探讨，因为已知src激酶参与了这些过程。此外，我们将进一步探索已知的蛋白关联（即Csk， Fyn）和棕榈酰化在将PAG靶向到GEMs中的作用，同时寻找新的蛋白，可能有助于我们充分了解这种新型接头的调节功能。我们将采用几种策略来观察这些相互作用的动力学，特别是在激活时发生的变化。最后，由于数据表明可能存在另一种类似pag的分子，我们将识别这种蛋白质。

In peripheral T-cells, the phosphoprotein associated with glycosphingolipid-enriched microdomains (PAG) appears to function as a negative regulator of cellular activation by recruiting the C-terminal Src-kinase (Csk) to the plasma membrane. Via its association to PAG, Csk is able to inhibit the activity of the membrane-associated Src-kinases p56lck and p59fyn. Upon activation, PAG becomes dephosphorylated by an unidentified phosphatase and its association with Csk is lost, allowing for the subsequent activation of the Src-kinases and the induction of signaling. The aim of this project is to identify the phosphatase responsible for this activity, as it is a potential target for regulating the activity of Src-kinases and thereby regulating the activity of T-cells. The role of PAG in T-cell development, the induction of anergy, adhesion and migration shall also be explored, as these are processes in which Src-kinases are known to be involved. Additionally, we shall further explore the known protein associations (i.e. Csk, Fyn) and the function of palmitoylation in targeting PAG to the GEMs, while also looking for new proteins that may help us to fully understand the regulatory functions of this novel adaptor. We shall employ several strategies to observe the dynamics of these interactions, in particular the changes which occur upon activation. Finally, as data suggests that there may be another PAG-like molecule, we shall identify this protein.