In Xenopus oocytes, mitogen-activated protein (MAP) kinase can be activated by progesterone treatment or by microinjection of cyclin A, both of which lead to activation of the cdc2 protein kinase. The tyrosine kinase pp60v-src has previously been shown to accelerate progesterone-induced oocyte maturation and to increase the phosphorylation of ribosomal protein S6 by pp90rsk, most likely by acti...

Chess, Patricia R., Michael A. O’Reilly, Fredrick Sachs, and Jacob N. Finkelstein. Reactive oxidant and p42/44 MAP kinase signaling is necessary for mechanical strain-induced proliferation in pulmonary epithelial cells. J Appl Physiol 99: 1226–1232, 2005. First published May 12, 2005; doi:10.1152/japplphysiol.01105.2004.— Mechanical strain is necessary for normal lung growth and development. In...

Increased serine phosphorylation of insulin receptor substrate-1 (IRS-1) has been observed in several systems to correlate with a decreased ability of the insulin receptor to tyrosine-phosphorylate this endogenous substrate and to inhibit its subsequent association with phosphatidylinositol 3-kinase. In the present studies we have examined the potential role of the mitogen-activated protein (MA...

The function of vascular endothelium as a biomechanical sensor permits alterations in gene expression in the vascular tree in response to wall stress. The present study explored the mechanism by which the arterial endothelium responds to changes in dietary salt. Normotensive rats were fed diets containing varying amounts of NaCl for 4 days. At that time, levels of phosphorylated p38 MAP kinase,...

Hypo-osmotic swelling of human Intestine 407 cells leads to a significant increase of intracellular MAPKAP-kinase 2 activity and Hsp27 phosphorylation. Pre-treatment of the cells with the p38 MAP kinase inhibitor SB-203580 blocks this activation, indicating that the hypotonicity-induced activation of MAPKAP kinase 2 is, similarly to that described for hyperosmotic treatment, the result of an ac...

p42mapk [mitogen activated protein (MAP) kinase; extracellular signal-regulated protein kinase (ERK)] is a serine/threonine-specific protein kinase that is activated by dual tyrosine and threonine phosphorylation in response to diverse agonists. Both the tyrosine and threonine phosphorylations are necessary for full enzymic activity. A MAP kinase activator recently purified and cloned has been ...

Adenosine exerts a mitogenic effect on human endothelial cells via stimulation of the A2A-adenosine receptor. This effect can also be elicited by the beta2-adrenergic receptor but is not mimicked by elevation of intracellular cAMP levels. In the present work, we report that stimulation of the A2A-adenosine receptor and of the beta2-adrenergic receptor activates mitogen-activated protein kinase ...

Dessy, Chantal, Inkyeom Kim, Carrie L. Sougnez, Regent Laporte, and Kathleen G. Morgan. A role for MAP kinase in differentiated smooth muscle contraction evoked by a-adrenoceptor stimulation. Am. J. Physiol. 275 (Cell Physiol. 44): C1081–C1086, 1998.—The purpose of this study was to investigate the potential role of mitogen-activated protein (MAP) kinase in smooth muscle contraction by monitori...

Activation of the mitogen-activated protein (MAP) kinase pathway has been associated with both cell proliferation and differentiation. Constitutively activated forms of Mek (MAP kinase/Erk kinase) and Erk (MAP kinase) have been previously shown capable of inducing differentiation or proliferation in nonhematopoietic cells. To specifically examine the role of Erk activation in megakaryocytic gro...

The Ras GTPase plays an essential role in many cellular signal transduction events. Activation of the mitogen activated protein (MAP) kinase is a primary consequence of Ras activation and plays a key role in mediating Ras signal transduction. A novel kinase, KSR, has recently been functionally isolated as a positive regulator of Ras signaling in Caenorhabditis elegans vulval induction and Droso...