To study the effects of contractile activity on mitogen-activated protein kinase (MAP kinase), p70 S6 kinase (p70S6K), and Akt kinase signaling in rat skeletal muscle, hindlimb muscles were contracted by electrical stimulation of the sciatic nerve for periods of 15 s to 60 min. Contraction resulted in a rapid and transient activation of Raf-1 and MAP kinase kinase 1, a rapid and more sustained ...

PURPOSE Tuberous sclerosis (TS) is a common autosomal disorder attributable to inactivation of the tumor suppressor genes tuberin and hamartin. To determine whether mitogen-activated protein (MAP) kinase signaling plays a role in the pathogenesis of TS, we stained human TS-associated neoplasms with antibodies directed against activated MAP kinase, and observed high-level expression. EXPERIMEN...

Background: Survival of the conceptus is dependent on continuous progesterone signaling in the maternal decidua but how this is achieved under conditions of oxidative stress that characterize early pregnancy is unknown. Materials and Methods: Laboratory-based analysis of endometrial biopsies and primary endometrial cultures. Results: Using primary cultures, we show that modest levels of reactiv...

The development of T cells in the thymus is coordinated by cell-specific gene expression programs that involve multiple transcription factors and signaling pathways. Here, we show that the p38 mitogen-activated protein (MAP) kinase signaling pathway is strictly regulated during the differentiation of CD4(-)CD8(-) thymocytes. Persistent activation of p38 MAP kinase blocks fetal thymocyte develop...

Inflammatory stimuli activate ectodomain shedding of TNF-alpha, L-selectin, and other transmembrane proteins. We show that p38 MAP kinase, which is activated in response to inflammatory or stress signals, directly activates TACE, a membrane-associated metalloprotease that is also known as ADAM17 and effects shedding in response to growth factors and Erk MAP kinase activation. p38alpha MAP kinas...

In C. elegans, a Wnt/WG-like signaling pathway down-regulates the TCF/LEF-related protein, POP-1, to specify posterior cell fates. Effectors of this signaling pathway include a beta-catenin homolog, WRM-1, and a conserved protein kinase, LIT-1. WRM-1 and LIT-1 form a kinase complex that can directly phosphorylate POP-1, but how signaling activates WRM-1/LIT-1 kinase is not yet known. Here we sh...

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...