title: LAB: a new membrane-associated adaptor molecule in B cell activation.
abstract: The adaptor molecule, linker for activation of T cells (LAT), is essential in T cell activation and development; a similar molecule in B cells has not yet been identified. Here, we report the identification of a new adaptor protein, linker for activation of B cells (LAB). Like LAT, LAB was localized to lipid rafts. Upon activation via the B cell receptor (BCR), LAB was phosphorylated and interacted with the adaptor protein Grb2. Decreased LAB expression led to a reduction in BCR-mediated calcium flux and Erk activation. LAB rescued thymocyte development but not normal T cell activation in LAT(-/-) mice. Our data suggest that LAB links BCR engagement to downstream signaling pathways.
authors.affiliation: Department of Immunology, Duke University Medical Center, Durham, NC 27710, USA.
authors.forename: Erin
authors.initials: E
authors.lastname: Janssen
authors.forename: Minghua
authors.initials: M
authors.lastname: Zhu
authors.forename: Weijia
authors.initials: W
authors.lastname: Zhang
authors.forename: Surapong
authors.initials: S
authors.lastname: Koonpaew
authors.forename: Weiguo
authors.initials: W
authors.lastname: Zhang
mesh_terms: D048868:Adaptor Proteins, Signal Transducing; D033942:Adaptor Proteins, Vesicular Transport / Q000235:genetics / Q000276:immunology* / Q000378:metabolism; D000595:Amino Acid Sequence; D000818:Animals; D001402:B-Lymphocytes / Q000276:immunology*; D002352:Carrier Proteins / Q000235:genetics / Q000276:immunology; D003001:Cloning, Molecular; D006801:Humans; D008213:Lymphocyte Activation; D008565:Membrane Proteins; D051379:Mice; D008810:Mice, Inbred C57BL; D018345:Mice, Knockout; D008969:Molecular Sequence Data; D010750:Phosphoproteins / Q000172:deficiency / Q000235:genetics / Q000276:immunology; D010766:Phosphorylation; D011506:Proteins; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D017386:Sequence Homology, Amino Acid; D015398:Signal Transduction; D014018:Tissue Distribution; D014443:Tyrosine / Q000378:metabolism
chemical_list: D048868:Adaptor Proteins, Signal Transducing; D033942:Adaptor Proteins, Vesicular Transport; D002352:Carrier Proteins; C471359:LAB protein, mouse; C110810:LAT protein, human; C419196:LAT2 protein, human; C488163:LAT2 protein, mouse; C491734:Lat protein, mouse; D008565:Membrane Proteins; D010750:Phosphoproteins; D011506:Proteins; D012333:RNA, Messenger; D014443:Tyrosine