Protein tyrosine kinases mitogen-activated

Sadoshima, J., Qiu, Z., Morgan, J.P., and Izumo, S. 1995. Angiotensin II and other hypertrophic stimuli mediated by G protein-coupled receptors activate tyrosine kinase, mitogen-activated protein kinase, and 90-kD S6 kinase in cardiac myocytes The critical role of Ca2+-dependent signaling. Circ. Res. 76 1-15. 

CaMK kinases are Ca2+/calmodulin regulated kinases, while CMGC Pks collect cyclic-dependent, mitogene-activated peptide (MAP) kinases, GSK3 and Clk kinases, that phosphorylate substrates in proline-rich domains. The last group are PTKs (protein tyrosine kinases), which include both receptor and non-receptor kinases, which phosphorylates tyrosine residues (this will be discussed in Sect. 4.3). 

The coupling of superantigen—major histocompatibility complex class II to T-cell receptor swifdy results in cell-signaling cascades. ° These staphylococcal toxins can increase levels of phosphatidyl inositol from quiescent T cells, such as other mitogens, as well as elicit intracellular Ca movement that activates the protein kinase C (PKC) pathway important for interleukin-2 (IL-2) expression. " IL-2 is intimately linked to T-cell proliferation. In addition to the PKC pathway, the protein tyrosine kinase (PTK) pathway is also activated by superantigens, leading to elevated expression of various proinflammatory cytokines. Staphylococcal superantigens also potently activate transcriptional factors NF-/IB (nuclear factor kappa B) and AP-1 (activator protein-1), which subsequently elicit the synthesis of proinflammatory cytokines. " " ... 

The most important pathways for transducing receptor activation by mitogens at the cell membrane into DNA synthesis and cell division involve PKC and protein tyrosine kinase (PTK). 

Figure 1. Schematic diagram of protein phosphatases and protein kinases (PK) on opening or closure of connexons. PTK protein tyrosine kinase MAPK mitogen activated protein kinases CasK casein kinase P indicates phosphorylation.

Keywords Adenylyl cyclase Aminoalkylindole Anandamide Ca Cannabinoid Cyclic AMP Depolarization suppression of inhibition or excitation Desensitization Endocannabinoid G proteins Ion channels Mitogen activated protein kinases Neurotransmission Nitric oxide Serine/threonine kinases Seven-transmembrane spanning receptors Synaptic plasticity Tyrosine kinases... 

ABBREVIATIONS APS, adaptor protein with PH and SH2 domains CAP, Cbl associated protein Crkll, chicken tumor virus regulator of kinase II GLUT4, glucose transporter 4 Gab-1, Grb-2 associated binder MAP kinase, mitogen-activated protein kinase PDK, phosphoinositide-dependent kinase PI3 kinase, phosphatidylinositol-3-kinase PIP3, phos-phatidylinositol trisphosphate PKB, protein kinase B (also called Akt) aPKC, atypical isoform of protein kinase C Y, tyrosine residue Y-P, phosphorylated tyrosine residue. 

Flavonols, 5-deoxykaempferol, kaempferol, quercetin, myricetin, and fise-tin, directly inhibit activities of multiple protein kinases such as tyrosine kinase activity in EGFR, Sre family kinase, mitogen-activated protein kinase. 

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