scholarly journals Protein Kinase C and Guanosine Triphosphate Combine to Potentiate Calcium-dependent Membrane Fusion Driven by Annexin 7

2002 ◽  
Vol 277 (28) ◽  
pp. 25217-25225 ◽  
Author(s):  
Hung Caohuy ◽  
Harvey B. Pollard
Keyword(s):  
Protein Kinase C ◽  
Protein Kinase ◽  
Membrane Fusion ◽  
Guanosine Triphosphate ◽  
Calcium Dependent ◽  
Kinase C

Expression of myogenic constrictor tone in the aorta of hypertensive rats

2001 ◽  
Vol 280 (4) ◽  
pp. R968-R975 ◽  
Author(s):  
Michelle Rapacon-Baker ◽  
Fan Zhang ◽  
Michael L. Pucci ◽  
Hui Guan ◽  
Alberto Nasjletti
Keyword(s):  
Protein Kinase C ◽  
Protein Kinase ◽  
Calcium Channels ◽  
Thoracic Aorta ◽  
Calcium Influx ◽  
Intraluminal Pressure ◽  
Hypertensive Rats ◽  
Calcium Dependent ◽  
Kinase C ◽  
Basal Tone

We investigated the effect of intraluminal pressure or stretch on the development of tone in the descending thoracic aorta from rats with aortic coarctation-induced hypertension of 7–14 days duration. Increments of pressure >100 mmHg decreased the diameter of thoracic aortas from hypertensive but not from normotensive rats. The pressure-induced constriction was not demonstrable in vessels superfused with calcium-free buffer. Stretched rings of aorta from hypertensive rats exhibited a calcium-dependent constrictor tone accompanied by elevated calcium influx that varied in relation to the degree of stretch. Blockers of l-type calcium channels and inhibitors of protein kinase C reduced both basal tone and calcium influx in aortic rings of hypertensive rats. Hence, the thoracic aorta of hypertensive rats expresses a pressure- and stretch-activated constrictor mechanism that relies on increased calcium influx throughl-type calcium channels via a protein kinase C-regulated pathway. The expression of such a constrictor mechanism is suggestive of acquired myogenic behavior.

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 A role for protein kinase C in the membrane fusion necessary for platelet granule secretion

Blood ◽  
1989 ◽  
Vol 74 (7) ◽  
pp. 2405-2413 ◽  
Author(s):  
JM Gerrard ◽  
LL Beattie ◽  
J Park ◽  
SJ Israels ◽  
A McNicol ◽  
...  
Keyword(s):  
Protein Kinase C ◽  
Protein Kinase ◽  
Membrane Fusion ◽  
Calcium Ionophore ◽  
Calcium Ionophore A23187 ◽  
Ultrastructural Changes ◽  
Ionophore A23187 ◽  
Kinase C ◽  
Granule Secretion ◽  
Dimethyl Amiloride

Abstract The addition of 1-oleoyl-2-acetylglycerol (OAG), or phorbol-12- myristate-13-acetate (PMA) to platelets induced the phosphorylation of a 47,000 dalton protein (47 Kd), fusion of granule membranes with membranes of the surface connected canalicular system, the formation of large vesicles and the secretion of serotonin. 1-(5- isoquinolinesulfonyl)-2-methyl-piperazine (H7), and sphingosine, inhibitors of protein kinase C, significantly inhibited the ultrastructural changes and the phosphorylation of 47 Kd. N-(2- guanidinoethyl)-5-isoquinolinesulfonamide (HA1004), structurally similar to H7, but a weaker inhibitor of protein kinase C, did not attenuate these responses to OAG or to PMA. H7, but not HA1004, also markedly inhibited secretion induced by the synergistic combination of OAG and the calcium ionophore A23187. Amiloride and 5-(N,N dimethyl)- amiloride, inhibitors of the Na+/H+ transporter, did not inhibit the ultrastructural response and the protein phosphorylation induced by OAG, or the secretion induced by the combination of A23187 and OAG. The results link the activation of protein kinase C by diglycerides to the labilization and fusion of granule membranes important for secretion.

scholarly journals HMGB1 Is Phosphorylated by Classical Protein Kinase C and Is Secreted by a Calcium-Dependent Mechanism

2009 ◽  
Vol 182 (9) ◽  
pp. 5800-5809 ◽  
Author(s):  
Young Joo Oh ◽  
Ju Ho Youn ◽  
Yeounjung Ji ◽  
Sang Eun Lee ◽  
Kook Jin Lim ◽  
...  
Keyword(s):  
Protein Kinase C ◽  
Protein Kinase ◽  
Calcium Dependent ◽  
Kinase C ◽  
Dependent Mechanism
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