The activities of PP1 (protein phosphatase 1), a principal cellular phosphatase that reverses serine/threonine protein phosphorylation, can be altered by inhibitors whose activities are themselves regulated by phosphorylation. We now describe a novel PKC (protein kinase C)-dependent PP1 inhibitor, namely GBPI (gut and brain phosphatase inhibitor). The shorter mRNA that encodes this protein, GBP...

The protein kinase family is a prime target for therapeutic agents, since unregulated protein kinase activities are linked to myriad diseases. Balanol, a fungal metabolite consisting of four rings, potently inhibits Ser/Thr protein kinases and can be modified to yield potent inhibitors that are selective-characteristics of a desirable pharmaceutical compound. Here, we characterize three balanol...

Angiotensin II (Ang II) induces vascular smooth muscle cell (VSMC) growth by activating Gq-protein-coupled AT1 receptors, which leads to elevation of cytosolic Ca2+ ([Ca2+]i) and activation of protein kinase C (PKC) and mitogen-activated protein kinases. To assess the link between these Ang II-induced signaling events, we examined the effect of Ang II on the proline-rich tyrosine kinase (PYK2),...

Protein kinase C (PKC)-θ, a serine/threonine protein kinase and novel PKC subfamily member, has been recently identified as an essential component of the T cell synapse which activates the NF-kB signaling cascade leading to expression of the IL-2 gene during T cell activation. By RNA in situ hybridization to whole-body embryo sections it is shown that the murine PKCθ is specifically...

The effect of tautomycin (TM) on protein kinase C (PKC) was studied in a cell-free system. TM, like phorbol dibutyrate (PDBu), enhanced both base-line and Ca2+/phospholipids-dependent protein kinase activity. However, PDBu but not TM increased the affinity of the enzyme for calcium ions (Ca2+), suggesting that TM is a new activator of PKC, distinct from PDBu. In the presence of 10 micrograms/ml...

PKC (protein kinase C) has been known for many years to modulate regulated exocytosis in a wide variety of cell types. In neurons and neuroendocrine cells, PKC regulates several different stages of the exocytotic process, suggesting that these multiple actions of PKC are mediated by phosphorylation of distinct protein targets. In recent years, a variety of exocytotic proteins have been identifi...

It has been demonstrated that proinsulin C-peptide possesses several biological activities and that its specific binding sites are present on the surface of cell membranes. However, the molecular and cellular mechanisms of C-peptide actions are poorly known. In the present study we examined the possible involvement of the mitogen-activated protein kinase (MAPK) pathway in C-peptide effects. C-p...

The mechanism(s) by which the c-myc nuclear protein and the mem brane-associated ras protein interact to mediate phenotypic changes is unknown. We now find that c-mcy gene expression is associated with alterations in the principal signal transduction pathway through which the ras protein is thought to function. We studied the transcript and protein expression of protein kinase C (PKC) isoforms ...

The mechanism(s) by which the c-myc nuclear protein and the membrane-associated ras protein interact to mediate phenotypic changes is unknown. We now find that c-mcy gene expression is associated with alterations in the principal signal transduction pathway through which the ras protein is thought to function. We studied the transcript and protein expression of protein kinase C (PKC) isoforms i...

Running title: PKC subtype-specific control of Ca 2+ oscillation receptor Total number of characters: 33,831-2-SUMMARY Prolonged activation of a metabotropic glutamate receptor, mGluR5a, causes synchronized oscillations in intracellular calcium, inositol 1,4,5-trisphosphate (IP 3) production, and protein kinase C (PKC) activation. Additionally, mGluR5 stimulation elicited cyclical translocation...