Eukaryotic cells kinase

As in all eukaryotic cells, protein kinases play an important role in the life cycle of the kinetoplastids and, as such, are attractive targets. Recent efforts, predominantly through genetic (RNAi) means, have validated a number of kinases as essential for survival of T. brucei, but few have been explored with chemical probes [33-35]. 

Mitogen-activated protein kinase phosphatases are dual-function protein phosphatases. Just as the MAPK kinases (e.g. MEKs) are unique as dual-functioning kinases in that they phosphorylate MAPKs on threonine and tyrosine residues, there are unique dual-function ing protein phosphatases that reverse the phosphorylation and activation of MAPKs [43], Such MAPK phosphatases (MKPs) were first identified as a product of vaccinia virus (VH1) and later found in all eukaryotic cells. There are now numerous members of this VH1 family of dual-functioning protein phosphatases. 

What are the mechanisms by which trichothecenes exert their transcriptional and post-transcriptional effects The 60S ribosomal subunit is a well-known molecular target of trichothecenes in leukocytes and other actively proliferating eukaryotic cells,3 whereas attempts to demonstrate alternative receptors have not been successful.37 38 Translational inhibitors that bind to ribosomes rapidly activate mitogen-activated protein kinases (MAPKs) and apoptosis via a mechanism termed the ribotoxic stress response. 39-40... 

Phosphorylation of serine, threonine, or tyrosine residues by protein kinases, and their dephosphorylation by protein phosphatases, are critical mechanisms by which information-relaying signals are transduced in eukaryotic cells. Although protein kinases are by no means an eukaryotic invention (see Leonard et al., 1998 for details), the large numbers of protein kinases in eukaryotes (118 in. S . cerevisiae and 435 in C. elegans (Chervitz et al., 1998)) reflect their importance in a multitude of diverse cellular processes. Eukaryotes have evolved signaling pathways that exploit the dual state of an amino acid, dependent on its state of phosphorylation, both as a signaling mechanism and as a means of colocalization of molecules within multimolecular complexes. 

Ro-4584820, a cyclin-dependent kinase (CDK) inhibitor, is in Phase 1 of clinical evaluation. CDKs are a family of serine/threonine protein kinases that play key roles in the normal growth and life cycle of eukaryotic cells. 

Prelich, G. RNA polymerase II carboxy-terminal domain kinases emerging clues to their function. Eukaryot. Cell, 1, 153-162 (2002)... 

Eukaryotic cells have six general types of signaling mechanisms gated ion channels receptor enzymes membrane proteins that act through G proteins nuclear proteins that bind steroids and act as transcription factors membrane proteins that attract and activate soluble protein kinases and adhesion receptors that carry information between the extracellular matrix and the cytoslceleton. 

Mechanisms for Regulating Protein Kinases Identify eight general types of protein kinases found in eukaryotic cells, and explain what factor is directly responsible for activating each type. 

The phosphoinositides constitute 2-8% of the lipid of eukaryotic cell membranes but are metabolized more rapidly than are other lipids.265 278 279 283 - 285 A simplified picture of this metabolism is presented in Fig. 11-9. Phosphatidylinositol is converted by the consecutive action of two kinases into phosphatidylinositol 4,5-bisphosphate.286287 The InsP3 released from this precursor molecule by receptor-stimulated phospholipase C is thought to mobilize calcium ions by... 

Hardie, D. G., Carling, D. and Carlson, M., 1998, The AMP-activated/SNFl protein kinase subfamily metabolic sensors of the eukaryotic cell , Annu Rev Biochem, 67, pp 821—55. 

Nigg, E. A., 1995, Cyclin-dependent protein kinases key regulators of the eukaryotic cell cycle. 

Chassagnole, C., Jackson, R.C., Hussain, N., Bashir, L., Derow, C., Savin, J., Fell, D.A. Using a mammalian cell cyde simulation to interpret differential kinase inhibition in anti-tumour pharmaceutical development. BioSystems 2006, 83 91-97. Csikasz-Nagy, A., Battogtokh, D., Chen, K.C., Novak, B., Tyson, J.J. Analysis of a generic model of eukaryotic cell-cycle regulation. Biophys J. 2006,90 4361-4379. Smith, J.A., Martin, L. Do cells cycle ... 

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