PI 3-kinase signaling pathway

After being phosphorylated, IRS provokes the activation of two separate pathways within the cell. From the IRS branching point come two signaling pathways, in the manner of two branches. These two branches are the PI 3-kinase signaling pathway and the RAS signaling pathway (Lawrence and Roach, 1997 Taha et ah, 1995) (Figure 4.13B). The branching point is represented by... 

Neurotrophins (NGF brain-derived neurotrophic factor, BDNF neurotrophin-3, NT-3 NT-4 NT-6) are important regulators of neural survival, development, function, and plasticity of the vertebrate nervous system [1]. Neurotrophins generally function as noncovalently associated homodimers. They activate two different classes of receptors, through which signaling pathways can be activated, including those mediated by Ras and members of the cdc42/rac/rho G protein families, MAP kinase, PI-3 kinase, and Jun kinase cascades. 

Number of papers to date have shown that the CXCR4 receptors expressed in both neuronal and glial cells are functional and coupled to multiple intracellular pathways (Lazarini et al. 2003). The CXCR4 through pertussis toxin (PTX)- sensitive G proteins is coupled to at least two distinct signaling pathways (1) the first pathway, involving the activation of phosphatidylinositol- 3 (PI-3) kinase and extracellular signal... 

Figure 7.1 Major signaling pathways relevant to this chapter. Simplified schematic diagram of the major signaling pathways which impinge on mRNA translation I. The phosphatidylinositide 3-kinase (PI 3-kinase) pathway II/III. MAP kinases, especially the classical MAP kinase (ERK) pathway and the p38 MAP kinase pathway IV. The mammalian target of rapamycin (mTOR) pathway. Strictly, this diagram shows the rapamycin-sensitive events linked to mTORCl. Selected inhibitors and their sites of action are shown. A numberof components and cross-connections have been omitted for clarity.

Abraham, R. T. (2004). PI 3-kinase related kinases Big players in stress-induced signaling pathways. DNA Repair (Amst.) 3, 883—887. 

Lopez-Ilasaca M, Crespo P, Pellici PG, et al. Linkage of G protein-coupled receptors to the MAPK signaling pathway through PI 3-kinase gamma. Science 1997 275 394—397. 

IGF-I may act as a survival factor via stimulation of the Bcl-2 family of proteins. Several signaling pathways such as tyrosine kinase, PI 3 kinase, and MAP kinase have also been suggested to mediate the antiapoptotic effects of IGF-I (Figure 13.6). 

Wenzel, S., Abdallah, Y., Helmig, S., Schaefer, C., Piper, H.M., and Schlueter, K.-D. 2006. Contribution of PI 3-kinase isoforms to angiotensin II- and a-adrenoceptor-mediated signalling pathways in cardiomyocytes. Cardiovasc. Res. 71 352-362. 

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