The receptors for insulin and epidermal growth factor undergo tyrosine autophosphorylation in response to ligand stimulation, while pp60v-src is an unregulated tyrosine kinase. In this report we show that each of the kinases phosphorylates an exogenous peptide that corresponds to the insulin proreceptor sequence 1142-1153. When the kinases were pre-phosphorylated, saturable Michaelis-Menten kin...

The glucocorticoid receptor (GR) is a member of the nuclear hormone receptor superfamily of ligand-activated transcription factors. In contrast to many other nuclear receptors, GR is thought to be exclusively cytoplasmic in quiescent cells, and only translocate to the nucleus on ligand binding. We now demonstrate significant nuclear GR in the absence of ligand, which requires nuclear localisati...

Local delivery of TGF-beta/BMP ligands is commonly used as a tissue engineering strategy for the spatial regulation of cell growth and differentiation. While the location and the dose of ligand are the only parameters that influence the spatial distribution and biological effects of the ligand in vitro, in vivo genetic studies of development reveal that spatial control of TGF-beta/BMP signaling...

BACKGROUND/AIMS The present study was performed to determine the effects of the ethyl acetate extract of Cudrania tricuspidata (EACT) on interleukin (IL)-1beta-stimulated receptor activator of NF-kappaB ligand (RANKL)-mediated osteoclast differentiation. METHODS Bone marrow cells were harvested from 6-week-old male imprinting control region mice, and the differentiation of osteoclasts from th...

Although several risk factors such as infarct size have been identified, the progression/severity of heart failure (HF) remains difficult to predict in clinical practice. Using an experimental rat model of ischemic HF and phosphoproteomic technology, we found an increased level of phosphorylated desmin in the left ventricle (LV) of HF-rats. The purpose of the present work is to assess whether d...

Homer proteins are components of postsynaptic density (PSD) and play a crucial role in coupling diverse target molecules. However, the regulatory aspect of Homer-mediated coupling has been addressed only about a dominant-negative effect of Homer1a, which requires de novo gene expression. Here, we present evidence that Homer-mediated coupling is regulated by its phosphorylation state. We found t...

Interleukin-6, leukemia inhibitory factor, and oncostatin M exert a broad range of similar biological activities through association of their receptors with the signal-transducing component gp130. Although it is known that these cytokines trigger rapid tyrosine phosphorylation of a common set of cellular proteins as well as induction of several of the same early response genes, the mechanisms b...

Arrestins bind ligand-activated, phosphorylated G protein-coupled receptors (GPCRs) and terminate the activation of G proteins. Additionally, nonvisual arrestin/GPCR complex can initiate G protein-independent intracellular signals through their ability to act as scaffolds that bring other signaling molecules to the internalized GPCR. Like nonvisual arrestins, vertebrate visual arrestin (ARR1) t...

Neuronal function depends on the retrograde relay of growth and survival signals from the synaptic terminal, where the neuron interacts with its targets, to the nucleus, where gene transcription is regulated. Activation of the Bone Morphogenetic Protein (BMP) pathway at the Drosophila larval neuromuscular junction results in nuclear accumulation of the phosphorylated form of the transcription f...

Ligation of the interleukin-7 receptor (IL-7R) results in a rapid phosphorylation of tyrosine residues on multiple substrates. In addition, we have recently shown that the IL-7R mediates activation of phosphatidylinositol-3 (PI-3) kinase. Because PI-3 kinase activity can be immunoprecipitated with antiphosphotyrosine antibodies in most receptor systems studied, it has been examined that either ...