Fibroblast Growth Factor

There are two separate forms of FGF, the basic FGF (bFGF) and the acidic FGF (aFGF), and these factors stimulate cell division in cell lines derived from neuroectoderm and mesoderm. The angiogenesis factor appears to be FGF, and FGF causes the proliferation of vascular endothelial cells, int-2, present in tumors, is related to FGF. hst-1 and kFGR are FGF-4. FGF-4 and -5 are related proteins, both oncogenes, and FGF-6 is related to hst.

bFGF is a 16-kDa, acid-labile protein, and aFGF is 15 kDa and has homology to bFGF. FGFs have affinity for heparin, which enhances the biological activity of FGF and increases its stability. FGFs are extracellular and may be secreted from the cell by Ca2+-dependent exocytosis. Outside the cell, bFGF associates with negatively charged proteoglycans. Thus, FGFs seem to be stored in the extracellular matrix. Receptors for FGF are fig and bek. They contain three IgG-like domains in the extracellular region; they have single transmembrane domains and tyrosine kinase in the cytoplasmic domains. Either receptor binds both forms of FGF. There are a large number of FGF receptor isoforms

FIGURE 19-7 Complete amino acid sequence of the 159-amino acid pro-TGF-a is shown as embedded in the plasma membrane. A consensus site for N-linked glycosylation is indicated, and cysteine residues within the cytoplasmic domain are marked with asterisks. Black arrows indicate sites of proteolytic cleavage that release the mature, 50-amino acid form. The open arrow near the amino terminus marks the apparent signal peptide cleavage site between amino acids 22 and 23. The open arrow immediately external to the plasma membrane marks a lysine-lysine bond that could serve as a cleavage site for a trypsin-like protease. Reproduced with permission from Lee, D. C., Luetteke, N. C., Qiu, T. H., Chen, X., and Berkowitz, E. A. (1993). Transforming growth factor-alpha. In "Growth Factors in Perinatal Development" (R. C. Tsang, J. A. Lemons, and W. F. Balistreri, eds.), pp. 21-38. Raven Press, NY.

FIGURE 19-7 Complete amino acid sequence of the 159-amino acid pro-TGF-a is shown as embedded in the plasma membrane. A consensus site for N-linked glycosylation is indicated, and cysteine residues within the cytoplasmic domain are marked with asterisks. Black arrows indicate sites of proteolytic cleavage that release the mature, 50-amino acid form. The open arrow near the amino terminus marks the apparent signal peptide cleavage site between amino acids 22 and 23. The open arrow immediately external to the plasma membrane marks a lysine-lysine bond that could serve as a cleavage site for a trypsin-like protease. Reproduced with permission from Lee, D. C., Luetteke, N. C., Qiu, T. H., Chen, X., and Berkowitz, E. A. (1993). Transforming growth factor-alpha. In "Growth Factors in Perinatal Development" (R. C. Tsang, J. A. Lemons, and W. F. Balistreri, eds.), pp. 21-38. Raven Press, NY.

deriving from splice variants of four different genes. FGF resembles PDGF in its biological activity, and its signal transduction process is similar to that of other growth factor receptors, including PDGF (Figure 19-4).

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Cure Tennis Elbow Without Surgery

Cure Tennis Elbow Without Surgery

Everything you wanted to know about. How To Cure Tennis Elbow. Are you an athlete who suffers from tennis elbow? Contrary to popular opinion, most people who suffer from tennis elbow do not even play tennis. They get this condition, which is a torn tendon in the elbow, from the strain of using the same motions with the arm, repeatedly. If you have tennis elbow, you understand how the pain can disrupt your day.

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