Ras and Raf-kinase interact through the Ras-binding (RBD) cysteine-rich domains (CRD) of Raf to signal mitogen-activated protein kinase pathway, yet molecular mechanism leading activation has remained elusive. We present 2.8 Å crystal structure HRas–CRaf-RBD_CRD complex showing Ras–Raf interface as a continuous surface on Ras, seen in KRas–CRaf-RBD_CRD structure. In dynamics simulations dimer m...

Background: B cells are specific antibody generating cells which respond to foreign intruders in the circulation. The purpose of this study was to compare the relative immunogenic potentials of three well established agent types viz. an immunogen, a mitogen and a carcinogen, by following B cell responses to their presence in a mouse model system. Methods: Mice were treated with tetanus toxoid (...

We have used mitogenic lectin (PHA) and a monoclonal antibody (OKT3) to stimulate human peripheral blood (G0) lymphocytes, in the presence of monocytes, and have found two major preferentially synthesized proteins, 73 and 95 kD, which are induced by the mitogens. The elevated synthesis of both proteins begins approximately 4-6 h after mitogen addition (early to mid G0/G1) before entry into firs...

MM14 mouse myoblasts withdraw irreversibly from the cell cycle and become postmitotic within a few hours of being deprived of fibroblast growth factor (Clegg, C. H., T. A. Linkhart, B. B. Olwin, and S. D. Hauschka, 1987, J. Cell Biol., 105:949-956). To examine the mechanisms that may regulate this developmental state of skeletal muscle, we tested the mitogen responsiveness of various cell types...

It is widely accepted that the neoplastic B cells from patients with chronic lymphocytic leukemia (CLL) respond poorly to common mitogens. The fungal metabolite cytochalasin B (0.5 micrograms/ml) is a weak mitogen for normal lymphocytes. However, when peripheral blood lymphocytes from 19 patients with CLL of B cell origin (B-CLL) were cultured with 0.5 micrograms cytochalasin B/ml, significant ...

The purified lymphocytosis promoting factor (LPF) from Bordetella pertussis was found to be a potent mitogen for peripheral blood lymphocytes (PBL) from normal adults as well as for cord blood lymphocytes. Proliferation occurred in autologous plasma or fetal calf serum, regardless of previous exposure to pertussis infection or immunization. Only one adult human serum, from a physician constantl...

Mitogen-Activated Protein Kinases (MAPKs) cascade plays an important role in regulating plant growth and development, generating cellular responses to the extracellular stimuli. MAPKs cascade mainly consist of three sub-families i.e. mitogen-activated protein kinase kinase kinase (MAPKKK), mitogen-activated protein kinase kinase (MAPKK) and mitogen activated protein kinase (MAPK), several casca...

Extracts of bovine hypothalamus were found to contain a significant level of mitogenic activity when tested in a Swiss 3T3 cell [3H]dThd incorporation assay and in a human umbilical vein endothelial cell growth assay. The mitogenic activity responsible for 3T3 cell activity was purified and characterized as a fibroblast growth factor (FGF)-like mitogen. Neither the biologically active FGF-like ...

Gold sodium thiomalate (GST) inhibited in vitro antigen- and mitogen-triggered human lymphocyte DNA synthesis. Inhibition of responsiveness was observed with concentrations of GST equivalent to gold levels found in serum or tissues of patients receiving chrysotherapy, Inhibition was dependent upon the gold ion itself since GST and gold chloride were both inhibitory whereas thiomalic acid was no...

The metabolism of glucose and glutamine in freshly prepared resting and concanavalin A-stimulated rat thymocytes was studied. Concanavalin A addition enhanced uptake of both glucose and glutamine and led to an increase in oxidative degradation of both substrates to CO2. With variously labelled [14C]glucose, it was shown that the pathways of glucose dissimilation were equally stimulated by the m...