scholarly journals Electron microscopic localization of type I protein kinase C in rat Purkinje cells

1988 ◽  
Vol 8 (11) ◽  
pp. 4262-4268 ◽  
Author(s):  
A Kose ◽  
N Saito ◽  
H Ito ◽  
U Kikkawa ◽  
Y Nishizuka ◽  
...  
Keyword(s):  
Protein Kinase C ◽  
Protein Kinase ◽  
Purkinje Cells ◽  
Type I ◽  
Electron Microscopic ◽  
Microscopic Localization ◽  
Kinase C ◽  
Electron Microscopic Localization

scholarly journals Modeled microgravity-induced protein kinase C isoform expression in human lymphocytes

2004 ◽  
Vol 96 (6) ◽  
pp. 2028-2033 ◽  
Author(s):  
A. Sundaresan ◽  
D. Risin ◽  
N. R. Pellis
Keyword(s):  
Protein Kinase C ◽  
Protein Kinase ◽  
Type I Collagen ◽  
Human Lymphocytes ◽  
Receptor Interaction ◽  
Type I ◽  
Modeled Microgravity ◽  
Calcium Dependent ◽  
Kinase C ◽  
Pkc Isoforms

In long-term space travel, the crew is exposed to microgravity and radiation that invoke potential hazards to the immune system. T cell activation is a critical step in the immune response. Receptor-mediated signaling is inhibited in both microgravity and modeled microgravity (MMG) as reflected by diminished DNA synthesis in peripheral blood lymphocytes and their locomotion through gelled type I collagen. Direct activation of protein kinase C (PKC) bypassing cell surface events using the phorbol ester PMA rescues MMG-inhibited lymphocyte activation and locomotion, whereas the calcium ionophore ionomycin had no rescue effect. Thus calcium-independent PKC isoforms may be affected in MMG-induced locomotion inhibition and rescue. Both calcium-dependent isoforms and calcium-independent PKC isoforms were investigated to assess their expression in lymphocytes in 1 g and MMG culture. Human lymphocytes were cultured and harvested at 24, 48, 72, and 96 h, and serial samples were assessed for locomotion by using type I collagen and expression of PKC isoforms. Expression of PKC-α, -δ, and -ϵ was assessed by RT-PCR, flow cytometry, and immunoblotting. Results indicated that PKC isoforms δ and ϵ were downregulated by >50% at the transcriptional and translational levels in MMG-cultured lymphocytes compared with 1- g controls. Events upstream of PKC, such as phosphorylation of phospholipase Cγ in MMG, revealed accumulation of inactive enzyme. Depressed calcium-independent PKC isoforms may be a consequence of an upstream lesion in the signal transduction pathway. The differential response among calcium-dependent and calcium-independent isoforms may actually result from MMG intrusion events earlier than PKC, but after ligand-receptor interaction.

scholarly journals Differential localization of protein kinase C isozymes in retinal neurons.

1991 ◽  
Vol 112 (6) ◽  
pp. 1241-1247 ◽  
Author(s):  
N Usuda ◽  
Y Kong ◽  
M Hagiwara ◽  
C Uchida ◽  
M Terasawa ◽  
...  
Keyword(s):  
Protein Kinase C ◽  
Protein Kinase ◽  
Bipolar Cells ◽  
Type I ◽  
Rabbit Retina ◽  
Type Ii ◽  
Retinal Neurons ◽  
Type Iii ◽  
Kinase C ◽  
Rod Bipolar Cells

We report the immunohistochemical localization of protein kinase C isozymes (types I, II, and III) in the rabbit retina using the monospecific monoclonal antibodies MC-1a, MC-2a, and MC-3a. Using immunoblot analysis of partially purified protein kinase C preparations of rabbit retina, types II and III isozymes alone were detected. The activity of type III was the stronger. By light microscopic immunohistochemical analysis, retinal neurons were negative for type I and positive for type II and type III isozymes. Type II was more diffusely distributed through the retinal layers, but was distinctive in ganglion cells, bipolar cells, and outer segments. The immunoreactivity was stronger for type III isozyme, and it was observed in mop (rod) bipolar cells and amacrine cells. By using immunoelectron microscopy, the cytoplasm of the cell body, the axon, and dendrites of the mop bipolar cells were strongly immunoreactive for type III. The so-called rod bipolar cells were for the first time seen to form synapses with rod photoreceptor cells. These differential localizations of respective isozymes in retinal neurons suggest that each isozyme has a different site of function in each neuron.

scholarly journals Purification of PKC-I, an endogenous protein kinase C inhibitor, and types II and III protein kinase C isoenzymes from human neutrophils

1992 ◽  
Vol 284 (2) ◽  
pp. 399-405 ◽  
Author(s):  
K J Balazovich ◽  
E L McEwen ◽  
M L Lutzke ◽  
L A Boxer ◽  
T White
Keyword(s):  
Protein Kinase C ◽  
Protein Kinase ◽  
Human Neutrophils ◽  
Type I ◽  
Dependent Manner ◽  
Type Ii ◽  
Western Blots ◽  
Type Iii ◽  
Kinase C ◽  
Endogenous Protein

Human neutrophil protein kinase C (PKC) activity is inhibited by an endogenous protein found primarily in the pellet fraction from homogenized specific granules, which was both heat- and proteinase-sensitive [Balazovich, Smolen & Boxer (1986) J. Immunol. 137, 1665-1673]. We now report that two PKC isoenzymes and the endogenous PKC inhibitor, which we named PKC-I, were purified from human neutrophils. A neutrophil soluble fraction that was subjected to DEAE-Sephacel chromatography yielded highly enriched PKC because, by definition, enzymic activity was strictly dependent on Ca2+ and phosphatidylserine. Hydroxyapatite chromatography resolved two peaks of PKC activity. Type II and Type III PKC isoenzymes were each identified on Western blots by using isoenzyme-specific monoclonal antibodies. Unlike rat brain, from which PKC isoenzymes were also purified, Type I PKC was not detected in human neutrophils. Western blots indicated that both Type II and Type III PKC isoenzymes had molecular masses near 80 kDa. In agreement with other reports, PKC was autophosphorylated in vitro. PKC-I, an endogenous neutrophil inhibitor of PKC, was purified to apparent homogeneity by DEAE-Sephacel and S-400 Sephacel chromatography. PKC-I had a molecular mass of 41 kDa. PKC-I inhibited purified PKC activity stimulated by 1,2-diacylglycerols in a concentration-dependent manner, and inhibited PKC-dependent phosphorylation of proteins present in neutrophil cytosol.

The role of intracellular calcium and protein kinase C in endothelin-stimulated proliferation of rat type I astrocytes

Glia ◽  
1995 ◽  
Vol 15 (2) ◽  
pp. 119-130 ◽  
Author(s):  
Danica B. Stanimirovic ◽  
Rita Ball ◽  
Geoff Mealing ◽  
Paul Morley ◽  
Jon P. Durkin
Keyword(s):  
Protein Kinase C ◽  
Protein Kinase ◽  
Intracellular Calcium ◽  
Type I ◽  
Kinase C

scholarly journals Regulation of heparan sulfate proteoglycan nuclear localization by fibronectin

2001 ◽  
Vol 114 (9) ◽  
pp. 1613-1623 ◽  
Author(s):  
T.P. Richardson ◽  
V. Trinkaus-Randall ◽  
M.A. Nugent
Keyword(s):  
Protein Kinase C ◽  
Protein Kinase ◽  
Heparan Sulfate ◽  
Nuclear Localization ◽  
Laser Scanning Microscopy ◽  
Type I ◽  
Heparin Binding ◽  
Kinase C ◽  
Core Proteins ◽  
In Cells

Heparan sulfate proteoglycans (HSPG) regulate multiple cellular processes and mediate the cellular uptake of numerous molecules. While heparan sulphate glycosaminoglycan chains are known to modulate receptor binding of several heparin-binding proteins, here we show that distinct extracellular matrices direct HSPG to the nucleus. We analyzed HSPG localization in primary corneal fibroblasts, cultured on fibronectin or collagen type I matrices, using confocal laser scanning microscopy and cell fractionation. Image analysis revealed that the nuclear localization of HSPG core proteins was greater when cells were cultured on fibronectin versus collagen. Matrices containing the heparin-binding domain of fibronectin, but not the integrin-activating domain, demonstrated increased nuclear staining of core proteins. Furthermore, activation of protein kinase C with phorbol 12-myristate 13-acetate inhibited nuclear targeting of HSPG in cells on fibronectin, whereas inhibition of protein kinase C with Ro-31-8220 greatly enhanced nuclear localization of HSPG in cells on both collagen and fibronectin. We propose a matrix-dependent mechanism for nuclear localization of cell surface HSPG involving protein kinase C-mediated signaling. Nuclear localization of HSPG might play important roles in regulating nuclear function.

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