FIGURE 5-28 Structure of human IGF-I, IGF-II, and insulin (ins), with amino acid residues aligned to show the homologies identified by the boxed areas. Single-letter codes are used for amino acid residues. Note that in insulin the C peptide is removed, whereas in IGF-I and IGF-II the A and B chains (domains) remain connected by the C peptide. In addition, there are D domains. Modified and reproduced, with permission, from Sara, Y. R., and Hall, K. (1990). Insulin-like growth factors and their binding proteins. Physiol. Rev. 70,591. Reproduced with permission from Ganong, W. F. (1995). "Review of Medical Physiology," 17th edition. Appleton and Lange, Norwalk, CT.
of other species, whereas the GH receptor from lower forms is able to bind GH of more than one species. The GH receptor dimerizes in contact with one GH molecule per dimer. Identical binding domains on each receptor monomer are bound by a single GH molecule. Phosphorylation of tyrosine residues on the GH receptor follows by interaction with the cytoplasmic JAK2 kinase, a member of the Janus family of kinases. The GH receptor does not have a tyrosine kinase catalytic center in its cytoplasmic domain. Further downstream events are not clear, except that in certain tissues, such
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All you need is a proper diet of fresh fruits and vegetables and get plenty of exercise and you'll be fine. Ever heard those words from your doctor? If that's all heshe recommends then you're missing out an important ingredient for health that he's not telling you. Fact is that you can adhere to the strictest diet, watch everything you eat and get the exercise of amarathon runner and still come down with diabetic complications. Diet, exercise and standard drug treatments simply aren't enough to help keep your diabetes under control.