The Akt and mitogen-activated protein kinase (MAPK) pathways have been implicated in tumor cell survival and contribute to radiation resistance. However, the molecular basis for link between MAPK and Akt in cell survival response to radiation is unclear. Here, we show that c-Src-Rac1-p38 MAPK pathway signals Akt activation and cell survival in response to radiation. Ionizing radiation triggered...

Our laboratory previously demonstrated that MAPK activation is an important signal during cytokine-induced endothelial permeability (Nwariaku FE, Liu Z, Terada L, Duffy S, Sarosi G, and Turnage R. Shock 18: 82-85, 2002). Because GTP-binding proteins have been implicated in MAPK activation, we now hypothesize that the GTP-binding protein Rho is a mediator of TNF-induced MAPK activation and incre...

BACKGROUND Gemcitabine is a pyrimidine nucleoside analog that is clinically active against pancreatic cancer. We have recently demonstrated that p38 MAPK is specifically activated by gemcitabine and that pharmacological blockade of p38 MAPK signaling prevented gemcitabine-induced apoptosis in human pancreatic cancer cells. In this study, we further investigated the implication of p38 MAPK in th...

The present study examined the effect of alterations in GnRH signal pattern (pulsatile vs. continuous; pulse frequency) on mitogen-activated protein kinase (MAPK) activity and whether MAPK plays a role in regulating gonadotrope gene expression. Pituitary MAPK activity was measured by immunoblot, using a phospho-specific MAPK antibody, corrected to the amount of total MAPK per sample. In vivo st...

AMP-activated protein kinase (AMPK) promotes glucose transport, maintains ATP stores, and prevents injury and apoptosis during ischemia. AMPK has several direct molecular targets in the heart but also may interact with other stress-signaling pathways. This study examined the role of AMPK in the activation of the p38 mitogen-activated protein kinase (MAPK). In isolated heart muscles, the AMPK ac...

Rapid induction of plant immune responses is essential to inhibit colonization and invasion by pathogens. Plants can recognize pathogen-associated molecular patterns (PAMPs) including fungal chitin and bacterial flagellin using pattern-recognition receptors (PRRs), which trigger the intracellular activation of mitogen-activated protein kinase (MAPK) cascades and the production of reactive oxyge...

Bistability of MAP kinase (MAPK) activity has been suggested to contribute to several cellular processes, including differentiation and long-term synaptic potentiation. A recent model (Markevich NI, Hoek JB, Kholodenko BN. J Cell Biol 164: 353-359, 2004) predicts bistability due to interactions of the kinases and phosphatases in the MAPK pathway, without feedback from MAPK to earlier reactions....

The mitogen-activated protein kinase (MAPK) is a pivotal point of convergence for many signaling pathways in eukaryotes. In the classical MAPK cascade, a signal is transmitted via sequential phosphorylation and activation of MAPK kinase kinase, MAPK kinase (MKK), and MAPK. The activation of MAPK is dependent on dual phosphorylation of a TXY motif by an MKK, which is considered the sole kinase t...

The mitogen-activated protein kinase (MAPK) pathway has been implicated recently in synaptic plasticity and memory. Here we used tail shock-induced sensitization of the tail-elicited siphon withdrawal reflex in Aplysia to examine the role of MAPK in three different phases of memory. We show that a specific pattern of serotonin (5-HT) application that produces intermediate-term and long-term syn...

Long-term facilitation of the sensory to motor synapse in Aplysia requires gene expression. While some transcription factors involved in long-term facilitation are phosphorylated by PKA, others lack PKA sites but contain MAP Kinase (MAPK) phosphorylation sites. We now show that MAPK translocates into the nucleus of the presynaptic but not the postsynaptic cell during 5-HT-induced long-term faci...