Mitogen-activated protein kinases mammalian cells

Figure 10.6 Schematic representation of the mitogen-activated protein kinase (MAP) cascades in mammalian cells. (From Voet and Voet, 2004. Reproduced with permission from John Wiley Sons., Inc.)...

FIGURE 10.6 Schematic representation of the mitogen-activated protein kinase (MAP) cascades in mammalian cells. 

Fig. 13.3 Signaling pathways involved in oxidized phospholipid-induced apoptosis in mammalian smooth muscle and endothelial cells. AIF, apoptosis inducing factor Apaf-1, apoptosis activating factor 1 aSM, acid sphingomyelinase Az-PC azelaoyl acid ester of lyso-PC Cyt c, cytochrome c G-PC, glutaric acid ester of lyso-PC IM, intermembrane space of the mitochondria JNK, c-Jun N-terminal kinase OV-PC, 5-oxovaleric acid ester of lyso-PC p38, p38 mitogen-activated protein kinase PM, plasma membrane...

Constitutive activation of cell survival pathways to induce frequent (incessant) cell divisions STAT, MARK, PBK/Akt, mTOR, Wnt/Hh, etc. (signal transducer and activator of transcription mitogen-activated protein kinase phosphatidyl inositol kinase 3 Ak mouse thymic lymphoma oncogene mammalian target of rapamycin wingless/hedgehog). 

Investigations of the cellular effects of radiofrequency radiation provide evidence of damage to various types of avian and mammalian cells. These effects involve radiofrequency interactions with cell membranes, especially the plasma membrane. Effects include alterations in membrane cation transport, Na+/K+-ATPase activity, protein kinase activity, neutrophil precursor membrane receptors, firing rates and resting potentials of neurons, brain cell metabolism, DNA and RNA synthesis in glioma cells, and mitogenic effects on human lymphocytes (Cleary 1990). 

As noted in Figure 23.23, one class of downstream kinases is called MAP kinase (MAPK). The acronym MAP stands for mitogen-activated protein. (A mitogen is a factor that stimulates mitosis.) Upstream of MAP kinases are another family of proteins, MAPKK (MAP kinase kinase), and still further upstream are the MAPKKK proteins (MAP kinase kinase kinase). One member of MAPKKK class of proteins is the product of the raf proto-oncogene (see Table 23.7). Mammalian cells contain seven known MAPKKKs, seven MAPKKs, and six MAPKs. 

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