title: B cell receptor-mediated antigen gathering requires ubiquitin ligase Cbl and adaptors Grb2 and Dok-3 to recruit dynein to the signaling microcluster.
abstract: The B cell receptor (BCR) mediates B cell antigen gathering and acquisition for presentation to T cells. Although the amount of antigen presentation to T cells determines the extent of B cell activation, the molecular mechanisms underlying antigen gathering remain unexplored. Here, through a combination of high-resolution imaging, genetics and quantitative mass spectrometry, we demonstrate that adaptors Grb2 and Dok-3, and ubiquitin ligase Cbl in signaling BCR microclusters mediate association with the microtubule motor dynein. Furthermore, we visualize the localization and movement of these microclusters on the underlying microtubule network. Importantly, disruption of this network or diminished dynein recruitment in Grb2-, Dok-3-, or Cbl-deficient B cells, does not influence microcluster formation or actin-dependent spreading, but abrogates directed movement of microclusters and antigen accumulation. Thus we identify a surprising but pivotal role for dynein and the microtubule network alongside Grb2, Dok-3, and Cbl in antigen gathering during B cell activation.
authors.affiliation: Lymphocyte Interaction Laboratory, London Research Institute, Cancer Research UK, 44 Lincoln's Inn Fields, London, WC2A 3LY, UK.
authors.forename: Tim
authors.initials: T
authors.lastname: Schnyder
authors.forename: Angelo
authors.initials: A
authors.lastname: Castello
authors.forename: Christoph
authors.initials: C
authors.lastname: Feest
authors.forename: Naomi E
authors.initials: NE
authors.lastname: Harwood
authors.forename: Thomas
authors.initials: T
authors.lastname: Oellerich
authors.forename: Henning
authors.initials: H
authors.lastname: Urlaub
authors.forename: Michael
authors.initials: M
authors.lastname: Engelke
authors.forename: Jürgen
authors.initials: J
authors.lastname: Wienands
authors.forename: Andreas
authors.initials: A
authors.lastname: Bruckbauer
authors.forename: Facundo D
authors.initials: FD
authors.lastname: Batista
mesh_terms: D048868:Adaptor Proteins, Signal Transducing / Q000276:immunology* / Q000378:metabolism; D000818:Animals; D000941:Antigens / Q000276:immunology*; D002478:Cells, Cultured; D004398:Dyneins / Q000276:immunology* / Q000378:metabolism; D051380:GRB2 Adaptor Protein / Q000276:immunology* / Q000378:metabolism; D051379:Mice; D008870:Microtubules / Q000378:metabolism; D011485:Protein Binding; D050721:Proto-Oncogene Proteins c-cbl / Q000276:immunology* / Q000378:metabolism; D011947:Receptors, Antigen, B-Cell / Q000276:immunology* / Q000378:metabolism; D015398:Signal Transduction; D014404:Tubulin / Q000378:metabolism
chemical_list: D048868:Adaptor Proteins, Signal Transducing; D000941:Antigens; C406768:Dok3 protein, mouse; D051380:GRB2 Adaptor Protein; C495949:Grb2 protein, mouse; D011947:Receptors, Antigen, B-Cell; D014404:Tubulin; D050721:Proto-Oncogene Proteins c-cbl; D004398:Dyneins; C493849:Cbl protein, mouse