Search results for "ras Protein"
showing 3 items of 53 documents
Tiam1 as a Signaling Mediator of Nerve Growth Factor-Dependent Neurite Outgrowth
2010
Nerve Growth Factor (NGF)-induced neuronal differentiation requires the activation of members of the Rho family of small GTPases. However, the molecular mechanisms through which NGF regulates cytoskeletal changes and neurite outgrowth are not totally understood. In this work, we identify the Rac1-specific guanine exchange factor (GEF) Tiam1 as a novel mediator of NGF/TrkA-dependent neurite elongation. In particular, we report that knockdown of Tiam1 causes a significant reduction in Rac1 activity and neurite outgrowth induced by NGF. Physical interaction between Tiam1 and active Ras (Ras- GTP), but not tyrosine phosphorylation of Tiam1, plays a central role in Rac1 activation by NGF. In add…
Targeting the mevalonate pathway for improved anticancer therapy.
2009
The mevalonate pathway is important for the generation of isoprene moieties thereby providing the basis for the biosynthesis of molecules required for maintaining membrane integrity, steroid production and cell respiration. Additionally, isoprene precursors are indispensable for the prenylation of regulatory proteins such as Ras and Ras-homologous (Rho) GTPases. These low molecular GTP-binding proteins play key roles in numerous signal transduction pathways stimulated upon activation of cell surface receptors by ligand binding. Thus, Ras/Rho proteins eventually regulate cell proliferation, tumor progression and cell death induced by anticancer therapeutics. Lipid modification of Ras/Rho pro…
Delivery of proteins into living cells by reversible membrane permeabilization with streptolysin-O
2001
The pore-forming toxin streptolysin O (SLO) can be used to reversibly permeabilize adherent and nonadherent cells, allowing delivery of molecules with up to 100 kDa mass to the cytosol. Using FITC-labeled albumin, 10 5 –10 6 molecules were estimated to be entrapped per cell. Repair of toxin lesions depended on Ca 2+ -calmodulin and on intact microtubules, but was not sensitive to actin disruption or to inhibition of protein synthesis. Resealed cells were viable for days and retained the capacity to endocytose and to proliferate. The active domains of large clostridial toxins were introduced into three different cell lines. The domains were derived from Clostridium difficile B-toxin and Clo…