Stress signaling pathway

Fig. 1. Signal transduction pathway Converts stress to a cellular response...

Phosphorylation of H3 is not limited to mitosis and also occurs in G1 phase of the cell cycle. Activation of the Ras-Raf-MEK-ERK signal transduction pathway and/or of the p38 stress kinase pathway when cells are treated with epidermal growth factor (EGF), 12-G-tetradecanoylphorbol-13-acetate (TPA), anesomycin, okadiac acid, and stresses such as UV irradiation induces the rapid phosphorylation of H3 at Ser-10 and/or Ser-28 [68-72] (Figs. 5 and 6). Inhibition of the MEK1,2 activity with PD98059 prevents the activation of ERK and TPA-induced H3... 

C. M. Payne, C. Bernstein and H. Bernstein, Apoptosis overview emphasizing the role of oxidative stress, DNA damage and signal-transduction pathways, Leuk. Lymphoma, 1995, 19(1-2), 43. 

Duman RS, Heninger GR, Nestler EJ Adaptations of receptor-coupled signal transduction pathways underlying stress- and drug-induced neural plasticity. J Nerv Ment Dis 182 692-700, 1994... 

Signaling pathways are also critical for the processing of sensory information. External stimuh, such as optical and acoustic signals, stress, gradients of nutrients, and so on, are registered in sensory cells and are transmitted to other cells of the organism via signaling pathways. 

Ruwhof C, van der Laarse A. 2000. Mechanical stress-induced cardiac hypertrophy mechanisms and signal transduction pathways. Cardiovasc Res 47 23-37. 

Kyriakis JM, Avruch J. 2001. Mammalian mitogen-activated protein kinase signal transduction pathways activated by stress and inflammation. Physiol Rev 81 807-869. 

Caspase activation occurs as a late and common step in all cells undergoing apoptosis. Nevertheless, there are many initial pathways that can result in caspase activation. Probably, each distinct pathway is triggered by different apoptotic stimuli. In mammalian cells, the apoptotic response is usually mediated by the intrinsic and extrinsic pathways, depending on the origin of the death signal. The intrinsic pathway can further be divided into mitochondrial and ER stress pathways. 

It has been shown in cell culture models of cXj-antitrypsin that Z-oq-antitrypsin in the ER causes expression of a novel set of stress genes with products that have the role of restoring ER function to normal. Z-a,-Antitrypsin induces two signal transduction pathways the ER overload response and unfolded protein response pathways. Via these transduction pathways, the presence of Z-oq-antitrypsin, as opposed to M-(Xj-antitrypsin, induces an hepatic inflammatory response. It is thought that this ER-specific stress response results in hepatic injury. 

Fig. 2 Outline of signal transduction pathways for stress kinases, JNKs, and for Map kinases, p38 and ERKl/2. Shown is the cross-talk between the various pathways. Map kinases MEKKl/2/3 activate the MAP kinases MKK4 (JNKKl) and MKK7 (JNKK2). MKK4/7 can also be activated by the Map kinases TAKl and Askl, which can also activate MKK3/6 of the p38 s pathway. Activation of Rap-GTP is capable of activating the p38 and ERKl/2 pathways. As indicated, ceramide can activate the p38 pathway, and, also, has been suggested to play a role in activation of the ERKl/2 pathway...

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