Ligand binding activation step

In the case of liganded NRs, ligand binding is the first and ciucial molecular event that switches the function of these transcription factors from inactive to active state by inducing a conformational change in the LBD of the receptor (Fig. 1). This specific conformation allows the second step of NR activation that corresponds to the recruitment of coregulatoiy complexes, which contain chromatin-modifying enzymes required for transcription. The transcriptional coactivators are very diverse and have expanded to more than hundred in number. These include the pi 60 family of proteins,... 

Xanthou G, Wilhams TJ, Pease JE (2003) Molecular characterization of the chemokine receptor CXCR3 evidence for the involvement of distinct extracellular domains in a multi-step model of ligand binding and receptor activation. Eur J Immunol 33 2927-2936 Xia MQ, Hyman BT (1999) Chemokines/chemokine receptors in the central nervous system and Alzheimer s disease. J Neurovirol 5 32-41... 

All steps of the Ras pathway from ligand binding to receptor tyrosine kinases, down to activation of effectors like Raf kinase, occur at the plasma membrane. However, most biophysical studies on protein/protein interactions involved in this scenario have been carried out with bacterially synthesized proteins lacking... 

This increase is thought to be one of the early steps involved in so-called signal transduction and can result in the activation of enzyme systems responsible for subsequent metabolic or developmental changes. Lymphocytes show increases in intracellular calcium in response to many kinds of specific and nonspecific surface ligand binding, some of which lead to the cellular changes that we associate with an immune response. Many other classes of cells also show calcium changes in response to stimulation. 

JAK is a family of cytoplasmic tyrosine kinases that are associated with cytokine receptors and play a major role in the initial steps of cytokine signaling. Upon ligand binding, JAKs are activated by /ra .s-phosphorylation of two receptor-bound JAK molecules and subsequently phosphorylate a number of substrates including the cytokine receptor (D3, S3, W8). The phosphorylated receptor... 

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