Indirect pathway

G6P is a phosphorylated form of glucose commonly found in cells. G6P is an intermediate in glycolysis, gluconeogenesis, the pentose phosphate pathway, the Calvin Cycle, glycogen biosynthesis, glycogen breakdown, and sugar interconversion. The latter three pathways indirectly involve G6P via the enzyme phosphoglucomutase. 

For the azides Ba(Ns)2 and Pb(N3)2, having similar stoichiometry but crystallizing in different systems, the difference is much more significant b/ b + 2c) is 12.3% and 39.3%, respectively. However, for lead azide, the primary decomposition pathway might be different [47] Pb(Ns)2 Pb(g) + N -h N2 + N3. The molar enthalpy of this reaction is 155kJ moP, which is consistent with the experimental value of 160kJ moP. The feasibility of this reaction pathway indirectly follows from features of the crystal structure of o -Pb(N3)2 [47]. This modification is the only stable form of... 

The first pathway (indirect pathway) involves two steps. 

However, the en2ymes of both pathways have been demonstrated in Candida utilis where xylose isomerase was found inducible and isomerization pathway occurred when xylose as the carbon source was alone in the medium [94, 95]. When both pentoses and hexoses were supplied to the medium, the conversion was carried out through oxido-reductive pathway. Indirect evidence for the presence of xylose isomerase in Rhodotorula gracilis and other yeast hke organisms has also been reported [96, 97]. 

The most general pathways to thiazoles bearing such groups as alkyl, aryl, aralkyl, and alkenyl, substituted or not by functional groups, are the cyclization reactions described in Chapter II. A certain number of indirect methods also exist, though only a few examples of each are given here. Others are discussed in the following chapters, with the more important references cited here. 

The indirect pathway by which air pollutants interact with plants is through the root system. Deposition of air pollutants on soils and surface waters can cause alteration of the nutrient content of the soil in the vicinity of the plant. This change in soil condition can lead to indirect or secondary effects of air pollutants on vegetation and plants. 

This is the case when the excitatory Dx receptors on these striatal GABAergic projection neurons are no longer activated since the transmitter dopamine is reduced (green broken arrows at 2). The indirect pathway is... 

Besides direct apoptosis effectors, there are a number of other diugs which influence the above explained apoptosis pathways more indirectly. This class of diugs includes molecules which inhibit survival pathways like e.g. the Ras/Raf kinase pathway, the NF-kB pathway and many others. Also inhibitors of survival cytokines which are sometimes produced by cancer cells in an autocrine fashion can render cells susceptible to apoptosis and, hence, effective cancer therapy. These include, but are not limited to, ligands for dependence receptors and cytokines like e.g. interleukin-4. 

A substantial amount of indirect evidence supports the contention that the induction of apoptosis in tumor cells is critical to successful therapy. Cancer therapy might therefore be viewed as an attempt to induce apoptosis in a population of cells that have undergone selection for apoptotic defects. If correct, this hypothesis would suggest why cancer therapy is in many cases unsuccessful. However, recent studies indicate that this fundamental problem can be circumvented. Progress in the identification of molecules key to the cell death pathways has led to a growing understanding of how apoptosis occurs [3]. It has become clear that pathways to apoptosis are numerous and often interconnected. A solution to the clinical problem of therapeutic resistance, then, may lie in the fact that there appears to be multiple ways that a cell death program can be implemented. 

Alterations to the P53 gene are the most common genetic defects known in cancer [5]. The protein product of P53 is involved in a number of pathways that directly and indirectly lead to apoptosis. Many genes that are involved in apoptosis can be induced by this protein, which is a transcriptional transactivator. The emerging hypothesis is that p53 is a central node of a complex apoptotic network that may function differ ently in diver se cell types and tissues. For example, Bax, the prototype proapoptotic member of the Bcl2 family, can be transcriptionally induced by p53 in certain, but not all, cell types. Like p53, Bax can modulate the extent to which cells are sensitive to apoptosis caused by therapeutic agents. 

The synthesis of virtually all proteins in a cell begins on ribosomes in the cytosol (except a few mitochondrial, and in the case of plants, a few chloroplast proteins that are synthesized on ribosomes inside these organelles). The fate of a protein molecule depends on its amino acid sequence, which can contain sorting signals that direct it to its corresponding organelle. Whereas proteins of mitochondria, peroxisomes, chloroplasts and of the interior of the nucleus are delivered directly from the cytosol, all other organelles receive their set of proteins indirectly via the ER. These proteins enter the so-called secretory pathway (Fig. 1). 

IP3 Receptors. Figure 1 Interplay between Ca2+ channels. Ca2+ signals are initiated when an extracellular stimulus (red) directly opens a Ca2+ channel in the plasma membrane or indirectly, via a signalling pathway (green), opens an intracellular Ca2+ channel. Ca2+ signals may then be propagated across the cell by Ca2+-induced Ca2+ release mediated by IP3R or RyR. 

In many cases, the values of A n and k2i may be directly or indirectly determined. We shall say no more about this relationship here, other than to indicate that it proves to be generally applicable, and is sufficiently accepted that the Marcus-Hush equation is now used to establish when an outer-sphere pathway is operative. In the context of this chapter, the involvement of the Kn term is interesting for it relates to the relative stabilization of various oxidation states by particular ligand sets. The factors which stabilize or destabilize particular oxidation states continue to play their roles in determining the value of Kn, and hence the rate of the electron transfer reaction. 

Fig. 3. A proposed signal transduction pathway regarding the external Ca effect on ginsenoside Rb synthesis by P. notoginseng cells. Ca signal changes are triggered by external Ca concentrations. The calcium signatures are decoded by calcium sensors, CaM and CDPK. UGRdGT is possibly modulated by the sensors in a direct or indirect (dashed lines) way. Changes of CDPK activity may result from increased synthesis or posttranslational modification of the enzyme (shown as CDPK ).

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