Early response genes

The events following the activation of Ras ultimately led to the activation of MAP kinase, followed by activation of expression of immediate-early response genes. Activation of MAP kinase requires two intermediate steps, both of which involve a phosphorylation (Figure 8.5). The immediate activator of MAP kinase is MAP-kinase-kinase (also called MAP kinase-ERK kinase, or MEK), a most unusual enzyme that phosphorylates MAP kinase on both a threonine (T) and a tyrosine (Y) residue. These are in the target-sequence seven residues (LTEYVATRWYRAPE) (Table 8.1)... 

Na+can also regulateNa,K-pump expression. Alterations in the local ionic environment, through changes in cytoplasmic Ca2+and Na+, can affect expression of the Na,K pump via early-response genes [18]. 

Peng, M., Huang, L., Xie, Z., Huang, W. H. and Askari, A. Partial inhibition of Na+/K+-ATPase by ouabain induces the Ca2+-dependent expressions of early-response genes in cardiac myocytes. /. Biol. Chem. 271 10372-10378,1996. 

Early response genes function as development-control signals 444... 

Early response genes function as development-control signals. How do epigenetic influences participate in decision making Environmental influences come in the form of growth factors, neurotransmitters and other ligands that are linked to changes in membrane receptors and... 

Arenander, A. A. and de Vellis, J. Early response gene expression signifying functional coupling of neuroligand receptor systems in astrocytes. In S. Murphy (ed.), Astrocytes. New York Academic Press, 1993, pp. 109-136. 

COXs thus catalyze the same first committed step of the AA cascade (Fig. 33-2). COX-2, however, is expressed in response to mitogenic and inflammatory stimuli and encoded by an early-response gene. To date we do not understand how COX-3 expression is regulated. In contrast, COX-1 expression is not subject to short-term regulation. Neurons in the hippocampus, as well as in a few other brain regions, are unlike other cells in that they display basal COX-2 expression [36]. This expression is modulated by synaptic activity, such as long-term potentiation, and involves the NMDA glutamate receptors [36,40]. 

ERG early-response genes HIV human immunodeficiency virus... 

The RAS-RAF-MAPK signaling pathway can cross-react with the JAK-STAT pathway in eosinophils (Fig. 1). It has been shown that MAPK interacts with the a subunit of IFN- //i receptor and the activation of early-response genes by IFNs requires tyrosine phosphorylation of STAT. Therefore, MAPK can regulate IFN-o and IFN-/1 activation of early-response genes by modifying the JAK-STAT signaling cascade (D5). 

Osteoblasts subjected to fluid shear increase expression of the early response gene, c-fos, and the inducible isoform of cyclooxygenase, COX-2, two proteins linked to anabolic response of bone to mechanical stimulation. Flow-induced responses in osteoblasts are mediated by inositol triphosphate intracellular calcium release. Flow-mediated stress is reported to induce both PGE2 and NO production. Fluid shear stress stimulates NO release by two distinct pathways a G-protein and calcium-dependent phase sensitive to flow gradients, and a G-protein and calcium-independent pathway stimulated by sustained flow. 

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