Multiple signal transduction

PTH has a dual effect on bone cells, depending on the temporal mode of administration given intermittently, PTH stimulates osteoblast activity and leads to substantial increases in bone density. In contrast, when given (or secreted) continuously, PTH stimulates osteoclast-mediated bone resorption and suppresses osteoblast activity. Further to its direct effects on bone cells, PTH also enhances renal calcium re-absorption and phosphate clearance, as well as renal synthesis of 1,25-dihydroxy vitamin D. Both PTH and 1,25-dihydroxyvitamin D act synergistically on bone to increase serum calcium levels and are closely involved in the regulation of the calcium/phosphate balance. The anabolic effects of PTH on osteoblasts are probably both direct and indirect via growth factors such as IGF-1 and TGF 3. The multiple signal transduction... 

Ganju RK, Brubaker SA, Meyer J, et al. The alpha-chemokine, stromal cell-derived factor-1 alpha, binds to the transmembrane G-protein-coupled CXCR-4 receptor and activates multiple signal transduction pathways. J Biol Chem 1998 273(36) 23169-23175. 

FIGURE 8.11 Multiple signal-transduction pathways initiated by calmodulin. Calmodulin bound to Ca2+ interacts and activates many enzymes, opening up a wide range of possible cellular responses. Abbreviations MAP-2, microtubule-associated protein 2 NO, nitric oxide Tau, tubulin assembly unit. 

Growth factors activate multiple signal transduction pathways required for survival and differentiation 473... 

Lackie, J. M. (1988). The behavioural repertoire of neutrophils requires multiple signal transduction pathways. J. Cell Sci. 89,449-452. 

Exogenously applied SIP binds to specific GPCRs to activate multiple signal transduction pathways. Additionally, some SIP could be taken up... 

Bi receptors may also be important in long-lasting kinin effects such as collagen synthesis and cell multiplication. By contrast, B2 receptors have a widespread distribution that is consistent with the multitude of biologic effects that are mediated by this receptor type. B2 receptors belong to the G protein-coupled family of receptors. Receptor binding sets in motion multiple signal transduction... 

Adham N, Borden LA, Schechter LE, et al. Cell-specific coupling of the cloned human 5-HTlp receptor to multiple signal transduction pathways. Naunyn Schmiedebergs Arch Pharmacol 1993 348 566-575. 

Noda M, Yasuda S, Okada M, et al. Recombinant human serotonin 5A receptors stably expressed in C6 glioma cells couple to multiple signal transduction pathways. J Neurochem 2003 84 222-232. 

Kroll, J., and Waltenberger, J. 1997. The vascular endothelial growth factor receptor KDR activates multiple signal transduction pathways in porcine aortic endothelial cells../. Biol. Chem. 272 32521-32527. 

In part two, we review the role of Pis in human disease. Although Pis are not abundant in biological systems, they have displayed numerous important functions in multiple signal transduction pathways. A number of human diseases are characterized by dysfunctional PI pathways, including cancer, type 2 diabetes, Lowe syndrome, myotubular myopathy, and Charcot-Marie-Tooth disease. 

Activation of multiple signal-transduction pathways by many receptors allows different sets of genes to be Independently controlled by the same or different receptors. Occasionally these pathways can induce opposite effects. For example, genetic manipulation of the Ras-MAP kinase and PT3 kinase pathways during muscle differentiation indicates that these pathways have opposite phenotypic effects activation of the Ras-MAP kinase pathway inhibits myocyte differentiation into myotubes, whereas activation of the PT3 kinase pathway promotes it. 

H.C. Huang, P.S. Klein, The Frizzled family receptors for multiple signal transduction pathways, Genome Biol. 2004, 5, 234.1-2234.7. 

Noda M, Higashida H, Aoki S. et al. Multiple signal transduction pathways mediated by 5-HT receptors. Mol Neurobiol 2004 29 31-39. 

Figure 12.3 Multiple signal transduction pathways initiated by calmodulin...

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