Thrombopoietin receptor (c-Mpl) is considered to regulate megakaryocytopoiesis. In this study, we investigated an effect of activation of a protein kinase C (PKC) on c-mpl promoter activity to elucidate the underlying mechanisms of c-mpl gene expression in megakaryoblastic cells. PKC is a member of a family of serine/threonine protein kinases in the cytosol involved in cell growth and different...

PKC (protein kinase C) isoenzymes are related protein kinases, involved in many signalling events in normal state and in disease. Basic research into identifying the molecular basis of PKC selectivity led to simple strategies to identify selective competitive inhibitor peptides and allosteric agonist peptides of individual PKC isoenzymes. The strategies and rationale used to identify these pept...

LPS induces in bone marrow macrophages the transient expression of mitogen-activated protein kinase (MAPK) phosphatase-1 (MKP-1). Because MKP-1 plays a crucial role in the attenuation of different MAPK cascades, we were interested in the characterization of the signaling mechanisms involved in the control of MKP-1 expression in LPS-stimulated macrophages. The induction of MKP-1 was blocked by g...

Activation of protein kinase C (PKC) by tumor-promoting phorbol esters leads to the phosphorylation of an 80-kilodalton PKC substrate (known as MARCKS) in murine fibroblasts. In BALB/c 3T3 cells stably transformed by v-Src, phorbol esters were unable to induce phosphorylation of MARCKS. Western blot analysis and in vitro kinase assays showed that both PKC protein levels and kinase activity were...

Transfer RNA-guanine ribosyltransferase (TGRase) irreversibly incorporates queuine into the first position in the anticodon of four tRNA isoacceptors. Rat brain protein kinase C (PKC) was shown to stimulate rat liver TGRase activity. TGRase preparations derived from rat liver have been observed to decrease in activity over time in storage at -20 or -70 degrees C. Contamination of the samples by...

VASP (vasodilator-stimulated phosphoprotein) is an actin- and profilin-binding protein that is expressed in platelets at high levels and plays a major role in negatively regulating secretory and adhesive events in these cells. VASP is a major substrate for cAMP- and cGMP-regulated protein kinases and it has been shown to be directly phosphorylated on Ser157 by PKC (protein kinase C). In the pre...

5-Hydroxytryptamine (5-HT) activates the extracellular signal-regulated kinase (Erk) mitogen-activated protein kinases (MAPKs) in the vasculature, resulting in contraction. The mechanisms by which this occurs are unclear. G protein-coupled receptors can activate Erk MAPK pathways through a variety of mechanisms, including stimulation of Src, phosphoinositide-3 kinase (PI-3-K), protein kinase C ...

Protein kinase C (PKC) isoforms have emerged as important regulators of cardiac contraction, hypertrophy, and signaling pathways that influence ischemic/reperfusion injury. This review focuses on newer concepts regarding PKC isoform-specific activation mechanisms and actions that have implications for the development of PKC-targeted therapeutics.

Protein kinase D (PKD) is a novel protein serine kinase which has recently been implicated in diverse cellular functions, including apoptosis and cell proliferation. The purpose of our present study was: (i) to define the activation of PKD in intestinal epithelial cells treated with hydrogen peroxide (H2O2), an agent which induces oxidative stress, and (ii) to delineate the upstream signaling m...

Background— Protein kinase C ( PKC) is involved in vascular smooth muscle cell (VSMC) activation, but little is known about its function in vascular pathology. We aimed at assessing the role of PKC in the development of restenosis. Methods and Results—Rat models of aortic balloon injury with or without subsequent stenting were used. Rats were treated with the selective PKC activator receptor fo...