title: The lymphocyte function-associated antigen-1 receptor costimulates plasma membrane Ras via phospholipase D2.
abstract: Ras activation as a consequence of antigen receptor (T-cell receptor; TCR) engagement on T lymphocytes is required for T-cell development, selection and function. Lymphocyte function-associated antigen-1 (LFA-1) mediates lymphocyte adhesion, stabilization of the immune synapse and bidirectional signalling. Using a fluorescent biosensor we found that TCR activation with or without costimulation of CD28 led to activation of Ras only on the Golgi apparatus, whereas costimulation with LFA-1 induced Ras activation on both the Golgi and the plasma membrane. Ras activation on both compartments required RasGRP1, an exchange factor regulated by calcium and diacylglycerol (DAG), but phospholipase C (PLC) activity was required only for activation on the Golgi. Engagement of LFA-1 increased DAG levels at the plasma membrane by stimulating phospholipase D (PLD). PLD2 and phosphatidic acid phosphatase (PAP) were required for Ras activation on the plasma membrane. Thus, LFA-1 acts through PLD2 to reshape the pattern of Ras activation downstream of the TCR.
authors.affiliation: Department of Medicine, NYU School of Medicine, New York, NY 10016, USA.
authors.forename: Adam
authors.initials: A
authors.lastname: Mor
authors.forename: Gabriele
authors.initials: G
authors.lastname: Campi
authors.forename: Guangwei
authors.initials: G
authors.lastname: Du
authors.forename: Yang
authors.initials: Y
authors.lastname: Zheng
authors.forename: David A
authors.initials: DA
authors.lastname: Foster
authors.forename: Michael L
authors.initials: ML
authors.lastname: Dustin
authors.forename: Mark R
authors.initials: MR
authors.lastname: Philips
mesh_terms: D000818:Animals; D018106:CD28 Antigens / Q000378:metabolism; D002450:Cell Communication / Q000502:physiology; D002462:Cell Membrane / Q000378:metabolism*; D004268:DNA-Binding Proteins / Q000378:metabolism; D004075:Diglycerides / Q000378:metabolism; D004789:Enzyme Activation / Q000502:physiology; D006056:Golgi Apparatus / Q000378:metabolism; D020662:Guanine Nucleotide Exchange Factors / Q000378:metabolism; D006801:Humans; D019169:Jurkat Cells; D016169:Lymphocyte Function-Associated Antigen-1 / Q000378:metabolism*; D051379:Mice; D008810:Mice, Inbred C57BL; D018345:Mice, Knockout; D010739:Phospholipase D / Q000378:metabolism*; D011948:Receptors, Antigen, T-Cell / Q000378:metabolism*; D015398:Signal Transduction / Q000502:physiology; D013601:T-Lymphocytes / Q000378:metabolism*; D010738:Type C Phospholipases / Q000378:metabolism; D018631:ras Proteins / Q000378:metabolism*
chemical_list: D018106:CD28 Antigens; D004268:DNA-Binding Proteins; D004075:Diglycerides; D020662:Guanine Nucleotide Exchange Factors; D016169:Lymphocyte Function-Associated Antigen-1; C491790:RASGRP1 protein, human; D011948:Receptors, Antigen, T-Cell; D010738:Type C Phospholipases; C105606:phospholipase D2; D010739:Phospholipase D; D018631:ras Proteins