Gerda Baumann

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Protein tyrosine kinases (PTKs) are implicated in cell proliferation, differentiation, and receptor-mediated signalling events. Recruitment of intracellular PTKs into the signalling complex, often localized at the inner surface of the cell membrane, involves SH2 and SH3 domains attached to the catalytic kinase domain. While the interaction of SH2 and SH3(More)
The acute-phase reactant rabbit serum amyloid A 3 (SAA3) was identified as the major difference product in Ag-induced arthritis in the rabbit, a model resembling in many aspects the clinical characteristics of rheumatoid arthritis (RA) in humans. In Ag-induced arthritis, up-regulated SAA3 transcription in vivo was detected in cells infiltrating into the(More)
Osteoblast cells, recruited from mesenchymal precursors, initiate the final phase of bone remodeling by secreting the protein components of the bone matrix. Upon completion of remodeling, some of these osteoblasts may further differentiate, giving rise to matrix-embedded osteocytes and bone lining cells. The fate of the remaining osteoblasts is unknown,(More)
Despite the successful clinical application of the immunosuppressive drug cyclosporin A (CsA, Sandimmun), its precise mechanism of action in the process of T cell activation remains elusive. CsA binds to the high-affinity cytosolic receptor cyclophilin whose peptidyl-prolyl cis-trans isomerase activity is inhibited upon binding. The linkage of this effect(More)
We report here on the identification of phosphopetide ligands which interact with the Src-homology 2 (SH2) domain of the adapter protein Grb2 by screening a random peptide library established on phage. Phage were phosphorylated in vitro at an invariant tyrosine residue by a mixture of phosphotyrosine kinases c-Src, Blk and Syk. Selection of binding motifs(More)
The immunosuppressive drug cyclosporin A (CsA, Sandimmun, SIM) is currently being evaluated in a variety of autoimmune disorders with some remarkable successes. Despite the wide empiric application of CsA, the precise mechanism of action of this drug remains elusive. To identify the molecular mode of action of CsA in the process of T cell activation, we(More)
The protein tyrosine kinase Syk plays an important role in signal transduction from the B cell antigen receptor and possibly also from the TCR. We have examined the binding specificity of Syk-derived SH2 domains in vitro and found that the tandem SH2 domains have two major ligands in activated Ramos B cells as well as in activated Jurkat T cells. The(More)