TY  - JOUR
A1  - Schneider-Schaulies, Jürgen
A1  - Schneider-Schaulies, Sibylle
A1  - Brinkmann, R.
A1  - Tas, P.
A1  - Halbrügge, M.
A1  - Walter, U.
A1  - Holmes, H.C.
A1  - ter Meulen, Volker
T1  - HIV-1 gp120 receptor on CD4-negative brain cells activates a tyrosine kinase
N2  - Human immunodeficiency virus (HIV-1) infection in the human brain Ieads to characteristic neuropathological changes, which may result indirectly from interactions of the envelope glycoprotein gp 120 with neurons and/or glial cells. We therefore investigated the binding of recombinant gp120 (rgp120) to human neural cells and its effect on int~acellular.s.ignallin~. Herewe pre~ent evidence that rgp120, besides binding to galactocerebroside or galactosyl-sulfatlde, spec1f1cally bmds to a protem receptor of a relative molecular mass of approximately 180,000 Da (180 kDa) pre~ent. on the CD4-negative glioma cells D-54, but not on Molt4 T lymphocytes. Binding of rgp120 to this receptor rap1dly 1nduced a tyrosine-specific protein kinase activity leading to tyrosine phosphorylation of 130- and 115-kDa p~oteins. The c~ncentration of intracellular calciumwas not affected by rgp120 in these cells. Our data suggest a novel Signal transduc1ng HIV-1 gp120 receptor on CD4-negative glial cells, which may contribute to the neuropathological changes observed in HIV-1-infected brains.
KW  - Immunologie
Y1  - 1992
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-54872
ER  - 
TY  - JOUR
A1  - Reinhard, Matthias
A1  - Halbrügge, Maria
A1  - Scheer, Ulrich
A1  - Wiegand, Christiane
A1  - Jockusch, Brigitte M.
A1  - Walter, Ulrich
T1  - The 46/50 kDa phosphoprotein VASP purified from human platelets is a novel protein associated with actin filaments and focal contacts
N2  - Vasoactive agents which elevate either cGMP or cAMP inhibit platelet activation by pathways sharing at least one component, the 46/50 kDa vasodilator-stimulated phosphoprotein (V ASP). V ASP is stoichiometrically phosphorylated by both cGMP-dependent and cAMPdependent protein kinases in intact human platelets, and its phosphorylation correlates very well with platelet inhibition caused by cGMP- and cAMP-elevating agents. Here we report that in human platelets spread on glass, V ASP is associated predominantly with the distal parts of radial micro filament bundles and with microfilaments outlining the periphery, whereas less V ASP is associated with a central microfilamentous ring. V ASP is also detectable in a variety of different cell types including fibroblasts and epithelial cells. In fibroblasts, V ASP is concentrated at focal contact areas, along microfilament bundles (stress fibres) in a punctate pattern, in the periphery of protruding lamellae, and is phosphorylated by cGMP- and cAMP-dependent protein kinases in response to appropriate stimuli. Evidence for the direct binding of V ASP to F -actin is also presented. The data demonstrate that V ASP is a novel phosphoprotein associated with actin filaments and focal contact areas, i.e. transmembrane junctions between microfilaments and the extracellular matrix.
KW  - cAMP / cGMP / cytoskeleton / phosphorylation / protein kinase
Y1  - 1992
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-34246
ER  -