title: Macromolecular assembly of the adaptor SLP-65 at intracellular vesicles in resting B cells.
abstract: The traditional view of how intracellular effector proteins are recruited to the B cell antigen receptor (BCR) complex at the plasma membrane is based on the occurrence of direct protein-protein interactions, as exemplified by the recruitment of the tyrosine kinase Syk (spleen tyrosine kinase) to phosphorylated motifs in BCR signaling subunits. By contrast, the subcellular targeting of the cytosolic adaptor protein SLP-65 (Src homology 2 domain-containing leukocyte adaptor protein of 65 kD), which serves as a proximal Syk substrate, is unclear. We showed that SLP-65 activation required its association at vesicular compartments in resting B cells. A module of ~50 amino acid residues located at the amino terminus of SLP-65 anchored SLP-65 to the vesicles. Nuclear magnetic resonance spectroscopy showed that the SLP-65 amino terminus was structurally disordered in solution but could bind in a structured manner to noncharged lipid components of cellular membranes. Our finding that preformed vesicular signaling scaffolds are required for B cell activation indicates that vesicles may deliver preassembled signaling cargo to sites of BCR activation.
authors.affiliation: Institute of Cellular and Molecular Immunology, Georg August University of Göttingen, Humboldtallee 34, 37073 Göttingen, Germany.
authors.forename: Michael
authors.initials: M
authors.lastname: Engelke
authors.affiliation: Institute of Cellular and Molecular Immunology, Georg August University of Göttingen, Humboldtallee 34, 37073 Göttingen, Germany.
authors.forename: Sona
authors.initials: S
authors.lastname: Pirkuliyeva
authors.affiliation: Institute of Cellular and Molecular Immunology, Georg August University of Göttingen, Humboldtallee 34, 37073 Göttingen, Germany.
authors.forename: Julius
authors.initials: J
authors.lastname: Kühn
authors.affiliation: Department of NMR-Based Structural Biology, Max Planck Institute for Biophysical Chemistry, Am Fassberg 11, 37077 Göttingen, Germany.
authors.forename: Leo
authors.initials: L
authors.lastname: Wong
authors.affiliation: Department of Neurobiology, Max Planck Institute for Biophysical Chemistry, 37077 Göttingen, Germany.
authors.forename: Janina
authors.initials: J
authors.lastname: Boyken
authors.affiliation: Institute of Cellular and Molecular Immunology, Georg August University of Göttingen, Humboldtallee 34, 37073 Göttingen, Germany.
authors.forename: Nadine
authors.initials: N
authors.lastname: Herrmann
authors.affiliation: Department of NMR-Based Structural Biology, Max Planck Institute for Biophysical Chemistry, Am Fassberg 11, 37077 Göttingen, Germany.
authors.forename: Stefan
authors.initials: S
authors.lastname: Becker
authors.affiliation: Department of NMR-Based Structural Biology, Max Planck Institute for Biophysical Chemistry, Am Fassberg 11, 37077 Göttingen, Germany.
authors.forename: Christian
authors.initials: C
authors.lastname: Griesinger
authors.affiliation: Institute of Cellular and Molecular Immunology, Georg August University of Göttingen, Humboldtallee 34, 37073 Göttingen, Germany. jwienan@gwdg.de.
authors.forename: Jürgen
authors.initials: J
authors.lastname: Wienands
mesh_terms: D048868:Adaptor Proteins, Signal Transducing / Q000737:chemistry* / Q000235:genetics / Q000276:immunology / Q000378:metabolism*; D001402:B-Lymphocytes / Q000737:chemistry / Q000378:metabolism*; D002462:Cell Membrane / Q000235:genetics / Q000276:immunology / Q000378:metabolism; D006801:Humans; D019906:Nuclear Magnetic Resonance, Biomolecular; D017434:Protein Structure, Tertiary; D011947:Receptors, Antigen, B-Cell / Q000235:genetics / Q000276:immunology / Q000378:metabolism; D022161:Transport Vesicles / Q000737:chemistry* / Q000235:genetics / Q000276:immunology / Q000378:metabolism*
chemical_list: D048868:Adaptor Proteins, Signal Transducing; C113939:B cell linker protein; D011947:Receptors, Antigen, B-Cell