title: Dynamic recruitment of PAK1 to the immunological synapse is mediated by PIX independently of SLP-76 and Vav1.
abstract: T cell receptor engagement activates p21-activated kinase 1 (PAK1) through a LAT-SLP-76-Nck-Vav-Rac-dependent pathway. A second independent pathway involving a GIT-PIX-PAK1 trimolecular complex is also activated by T cell receptor ligation. Here we show a Vav-independent pathway exists that leads to PAK1 activation. In addition, PAK1, PIX and GIT1 were recruited to the T cell-antigen-presenting cell contact site independently of SLP-76 and Vav1. PAK1 recruitment to the T cell-antigen-presenting cell interface required interaction with PIX, which also led to optimal PLC-gamma1 activation and T cell receptor-dependent transcriptional responses. These data indicate that a pathway involving the GIT-PIX-PAK1 complex has a crucial function in PAK1 activation by recruiting PAK1 to the immunological synapse.
authors.affiliation: Department of Medicine, Howard Hughes Medical Institute, Rosalind Russell Medical Research Center for Arthritis, University of California San Francisco, 94143, USA.
authors.forename: Hyewon
authors.initials: H
authors.lastname: Phee
authors.forename: Robert T
authors.initials: RT
authors.lastname: Abraham
authors.forename: Arthur
authors.initials: A
authors.lastname: Weiss
mesh_terms: D048868:Adaptor Proteins, Signal Transducing; D000938:Antigen-Presenting Cells / Q000276:immunology / Q000378:metabolism; D001483:Base Sequence; D001665:Binding Sites; D018797:Cell Cycle Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D004247:DNA / Q000235:genetics; D020662:Guanine Nucleotide Exchange Factors / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D006801:Humans; D019169:Jurkat Cells; D046912:Multiprotein Complexes; D051966:Phospholipase C gamma; D010750:Phosphoproteins / Q000172:deficiency / Q000378:metabolism*; D017346:Protein Serine-Threonine Kinases / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D011518:Proto-Oncogene Proteins / Q000172:deficiency / Q000378:metabolism*; D051567:Proto-Oncogene Proteins c-vav; D011948:Receptors, Antigen, T-Cell / Q000378:metabolism; D011994:Recombinant Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D064067:Rho Guanine Nucleotide Exchange Factors; D015398:Signal Transduction; D013601:T-Lymphocytes / Q000276:immunology / Q000378:metabolism; D014158:Transcription, Genetic; D010738:Type C Phospholipases / Q000037:antagonists & inhibitors; D020764:cdc42 GTP-Binding Protein / Q000378:metabolism; D054462:p21-Activated Kinases; D020744:rac GTP-Binding Proteins / Q000378:metabolism
chemical_list: D048868:Adaptor Proteins, Signal Transducing; D018797:Cell Cycle Proteins; D020662:Guanine Nucleotide Exchange Factors; D046912:Multiprotein Complexes; D010750:Phosphoproteins; D011518:Proto-Oncogene Proteins; D051567:Proto-Oncogene Proteins c-vav; D011948:Receptors, Antigen, T-Cell; D011994:Recombinant Proteins; D064067:Rho Guanine Nucleotide Exchange Factors; C092947:SLP-76 signal Transducing adaptor proteins; C496618:VAV1 protein, human; D004247:DNA; C515903:PAK1 protein, human; D017346:Protein Serine-Threonine Kinases; D054462:p21-Activated Kinases; D010738:Type C Phospholipases; D051966:Phospholipase C gamma; D020764:cdc42 GTP-Binding Protein; D020744:rac GTP-Binding Proteins