Guard cells form stomata on the epidermis and continuously respond to endogenous and environmental stimuli to fine-tune the gas exchange and transpirational water loss, processes which involve mitogen-activated protein kinase (MAPK) cascades. MAPKs form three-tiered kinase cascades with MAPK kinases and MAPK kinase kinases, by which signals are transduced to the target proteins. MAPK cascade ge...

The Podospora anserina PaMpk1 MAP kinase (MAPK) signaling pathway can generate a cytoplasmic and infectious element resembling prions. When present in the cells, this C element causes the crippled growth (CG) cell degeneration. CG results from the inappropriate autocatalytic activation of the PaMpk1 MAPK pathway during growth, whereas this cascade normally signals stationary phase. Little is kn...

We have investigated the adrenergic control of mitogen-activated protein kinase (MAPK) activity in brown adipocytes. Cold exposure in rats led to an activation of MAPK in brown adipose tissue, as determined by the gel mobility shift assay and in-gel kinase assay. In contrast, no activation was seen after surgical sympathetic denervation of the tissue. The neurotransmitter, norepinephrine (NE), ...

Multi-potent adult progenitor cells (MAPCs) differentiate into endothelial cells (ECs) in the presence of vascular endothelial growth factor (VEGF). The mechanism(s) of VEGF-induced differentiation of MAPCs to ECs are not yet known. We, therefore, examined the role of mitogen-activated protein kinase/extracellular signal-regulated kinase (p42/44-MAPK/ERK1/2) signalling in endothelial differenti...

Evidence suggests that p38 mitogen-activated protein kinase (MAPK) activation influences cardiac function on an acute basis. The characterization and mechanisms by which this occurs were investigated in the present study. Adult rat ventricular myocytes treated with 1 mM arsenite for 30 min had a 16-fold increase in p38 MAPK phosphorylation that was attenuated by SB-203580 (a p38 MAPK inhibitor)...

A variety of G protein-coupled receptors (GPCRs) are phosphorylated by G protein-coupled receptor kinase 2 (GRK2). This event promotes the binding of regulatory proteins termed beta-arrestins to GPCRs, leading to uncoupling from G proteins and receptor internalization. Recent data indicate that GRK2 and beta-arrestins also play an important role in the stimulation of the extracellular signal-re...

To clarify the differences of the signaling pathways used by granulocyte colony-stimulating factor (G-CSF), granulocytemacrophage colony-stimulating factor (GM-CSF), and tumor necrosis factor-a (TNF), we investigated activation of mitogen-activated protein kinase (MAPK) subtype cascades in human neutrophils stimulated by these cytokines. G-CSF exclusively tyrosine-phosphorylated extracellular s...

Redox and ROS regulation of MAPK-mediated TNF-alpha biosynthesis is not well characterized. It was hypothesized that the involvement of the MAPK pathway in regulating LPS-mediated TNF-alpha secretion is redox-dependent, NF-kappaB-sensitive and attenuated by N-acetyl-L-cysteine (NAC) and other antioxidants. In alveolar epithelial cells, LPS induced a time- and dose-dependent phosphorylation of M...