Subject transduction signal

R Genes Cis Elements, Trans-factors and Signal Transduction Systems in the Lens, Joram Piatigorksy and Peggy S. Zelen-ka, National Eye Institute, National Institutes of Health, Maryland. Subject Index. 

A second well characterized signal transduction pathway, which is subject to lithium inhibition, is the phosphoinositol cascade (see Chapter 11, in particular Figure 11.8). A number of enzymes of this pathway contain a common amino acid sequence that constitutes a lithium-sensitive Mg2+ binding site, and it has been proposed that lithium exerts some of... 

About 10-20% of all transmembrane proteins that are targeted to the ER and subsequently enter the secretory pathway are subject to post-translational modification with glycosylphosphatidyl-inositol (GPI). Proteins bearing the GPI anchor are involved in signal transduction, immune response, cancer cell invasion, and metastasis and the pathobiology of trypanosomal parasites. The structure of the GPI anchor has been analyzed for mammals, protozoa, and yeast. The general structure of the glycolipid structure is shown in Scheme 4. 

Due to these functions, the protein phosphatases are an indispensable part of signal transduction processes involving protein phosphorylation. It is therefore not surprising that the protein phosphates are subject to diverse and complex regulation. 

Signal transduction between Ras protein and Raf kinase is based on a specific interaction of the two proteins, which can only be performed by the activated, GTP-bound form of Ras protein. The inactive, GDP-form of Ras protein shows significantly weaker binding to Raf kinase (Herrmann et al., 1995). Complex formation is not linked to stimulation of GTPase activity of Ras protein, and thus it is assumed that termination of signal transduction only occins on dissociation of Raf kinase or hydrolysis of the boimd GTP. The lifetime of the GTP state is determined by the GTPase activity of the Ras protein, which itself is subject to regulation by GAP proteins. 

There is a huge variety of plant defensive secondary metabolites that has been the subject of major phytochemical [1-6] or pharmacological and toxicological [7-12] compilations. This structural complexity is very briefly reviewed below before considering those plant bioactives with signal transduction targets. The major groups are the phenolics, the terpenoids and the alkaloids as well as bioactives structurally related to... 

Monoamine oxidases (MAOs) are found in the mitochondria of almost all cells. Most neurotransmitters are amines and subject to oxidation by MAOs. Members of the MAO inhibitor (MAOI) class of antidepressants slow the destruction of neurotransmitters in neurons and cause stronger signal transduction. Selected examples of MAOIs are shown in Figure A.17. 

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