title: Regulation of Vav localization in membrane rafts by adaptor molecules Grb2 and BLNK.
abstract: Despite the importance of the Vav family proteins for B cell receptor (BCR) signaling, their activation mechanisms remain poorly understood. We demonstrate here that adaptor molecules Grb2 and BLNK, in addition to Vav, are required for efficient Rac1 activation in response to BCR stimulation. Loss of either Grb2 or BLNK results in decreased translocation of Vav3 to membrane rafts. By expression of Vav3 as a raft-targeted construct, the defective Rac1 activation in Grb2- or BLNK-deficient B cells is restored. Hence, our findings suggest that Grb2 and BLNK cooperate to localize Vav into membrane rafts, thereby contributing to optimal activation of Vav in B cells.
authors.affiliation: Department of Molecular Genetics, Institute for Liver Research, Kansai Medical University, 10-15 Fumizono-cho, Moriguchi 570-8506, Japan.
authors.forename: Sachiko
authors.initials: S
authors.lastname: Johmura
authors.forename: Masatsugu
authors.initials: M
authors.lastname: Oh-hora
authors.forename: Kazunori
authors.initials: K
authors.lastname: Inabe
authors.forename: Yumiko
authors.initials: Y
authors.lastname: Nishikawa
authors.forename: Katsuhiko
authors.initials: K
authors.lastname: Hayashi
authors.forename: Elena
authors.initials: E
authors.lastname: Vigorito
authors.forename: Daisuke
authors.initials: D
authors.lastname: Kitamura
authors.forename: Martin
authors.initials: M
authors.lastname: Turner
authors.forename: Koh
authors.initials: K
authors.lastname: Shingu
authors.forename: Masaki
authors.initials: M
authors.lastname: Hikida
authors.forename: Tomohiro
authors.initials: T
authors.lastname: Kurosaki
mesh_terms: D048868:Adaptor Proteins, Signal Transducing; D000818:Animals; D001402:B-Lymphocytes / Q000378:metabolism; D002352:Carrier Proteins / Q000378:metabolism*; D018797:Cell Cycle Proteins; D020662:Guanine Nucleotide Exchange Factors; D021962:Membrane Microdomains / Q000378:metabolism*; D051379:Mice; D010750:Phosphoproteins / Q000378:metabolism*; D011518:Proto-Oncogene Proteins / Q000378:metabolism*; D051567:Proto-Oncogene Proteins c-vav; D011947:Receptors, Antigen, B-Cell / Q000378:metabolism
chemical_list: D048868:Adaptor Proteins, Signal Transducing; C113939:B cell linker protein; D002352:Carrier Proteins; D018797:Cell Cycle Proteins; D020662:Guanine Nucleotide Exchange Factors; D010750:Phosphoproteins; D011518:Proto-Oncogene Proteins; D051567:Proto-Oncogene Proteins c-vav; D011947:Receptors, Antigen, B-Cell; C496619:Vav1 protein, mouse; C496622:Vav3 protein, mouse