Ras activation in Jurkat T cells following low-grade stimulation of the T-cell receptor is specific to N-Ras and occurs only on the Golgi apparatus.

摘要: Ras activation is critical for T-cell development and function, but the specific roles of different isoforms in T-lymphocyte function are poorly understood. We recently reported receptor (TCR) ectopically expressed H-Ras on Golgi apparatus T cells. Here we studied isoform subcellular compartment specificity signaling Jurkat was at much lower levels than other several lines. Glutathione S-transferase-Ras-binding domain (RBD) pulldown assays revealed that, although high-grade TCR stimulation phorbol ester activated both N-Ras K-Ras, low-grade resulted N-Ras. Surprisingly, whereas cocapped with TCRs lipid microdomains plasma membrane, did not. Live-cell imaging cells expressing green fluorescent protein-RBD, a reporter GTP-bound Ras, that occurs exclusively phospholipase Cgamma- RasGRP1-dependent fashion. The downstream dependent monoacylation hypervariable membrane targeting sequence. Our data show contrast to fibroblasts stimulated growth factors which all three become apparatus, Golgi-associated intracellular pool