Translocation of protein kinase C in human polymorphonuclear neutrophils. Regulation by cytosolic Ca2(+)-independent and Ca2(+)- dependent mechanisms

HOME

HELP

FEEDBACK

SUBSCRIPTIONS

Translocation of protein kinase C in human polymorphonuclear neutrophils. Regulation by cytosolic Ca2(+)-independent and Ca2(+)- dependent mechanisms

JT O'Flaherty, DP Jacobson, JF Redman and AG Rossi
Department of Medicine, Wake Forest University Medical Center, Winston- Salem, North Carolina 27013.

[3H]Phorbol dibutyrate [( 3H]PDB) rapidly and reversibly binds to human polymorphonuclear neutrophils (PMN). Ca2+/diacylglycerol/phospholipid- dependent protein kinase C appeared to be the receptor for this binding because: a diacylglycerol, dioctanoylglycerol, competed with [3H]PDB for PMN binding sites; a blocker of protein kinase C-phospholipid interactions, sphinganine, inhibited PMN binding of [3H]PDB; and changes in cytosolic Ca2+ apparently regulated PMN binding of the label. Relevant to the last point, disrupted PMN contained 9 X 10(5) phorbol diester receptors/cell, whereas intact PMN had only 1.6 X 10(5) such receptors that were accessed by the ligand. This number fell to 1.0 X 10(5) in Ca2(+)-depleted PMN and rose to 2.5 X 10(5) in cells stimulated with the Ca2+ ionophore, ionomycin. This ionomycin effect lasted for greater than 16 min, correlated temporally with changes in cytosolic Ca2+, did not occur in Ca2(+)-depleted PMN, and was blocked by sphinganine. A second ionophore, A23187, likewise induced Ca2(+)- dependent rises in [3H]PDB binding. These results fit the standard model, wherein rises in cytosolic Ca2+ cause protein kinase C to translocate from cytosol to plasmalemma and thereby become more available to [3H]PDB. In contrast, two humoral agonists, N-formyl-Met- Leu-Phe (fMLP) and leukotriene (LT)B4, had actions that did not fit this model. They stimulated PMN to increase the availability of PDB binding sites by a sphinganine-sensitive mechanism, but their actions differed from those of ionophores. They induced biphasic (t = 15 and 60 s) increases in [3H]PDB binding while eliciting monophasic (t = 15 s), short-lived (t less than 1 min) rises in cytosolic Ca2+. In Ca2(+)- depleted PMN, moreover, fMLP and LTB4 stimulated slow (t greater than or equal to 30 s), monophasic, prominent rises in [3H]PDB binding and binding site number without appreciably altering cytosolic Ca2+. We suggest, therefore, that fMLP and LTB4 translocate protein kinase C using two sequential mechanisms. The first involves Ca2+ transients and thus produces abrupt (t = 15 s), rapidly reversing responses. The second mechanism uses an unrelated signal to effect a more slowly evolving (t = 60 s) movement of protein kinase C to plasmalemma. Hence, the standard model does not explain all instances of protein kinase C translocation, and a cytosolic Ca2(+)-independent signal contributes to the regulation of protein kinase C as well as those responses elicited by the effector enzyme.
Add to CiteULike CiteULike Add to Complore Complore Add to Connotea Connotea Add to Del.icio.us Del.icio.us Add to Digg Digg Add to Reddit Reddit Add to Technorati Technorati What's this?

This article has been cited by other articles:

M. Ding, C. Huang, Y. Lu, L. Bowman, V. Castranova, and V. Vallyathan
Involvement of protein kinase C in crystalline silica-induced activation of the MAP kinase and AP-1 pathway
Am J Physiol Lung Cell Mol Physiol, February 1, 2006; 290(2): L291 - L297.
[Abstract] [Full Text] [PDF]

C. H. C. Serezani, D. M. Aronoff, S. Jancar, P. Mancuso, and M. Peters-Golden
Leukotrienes enhance the bactericidal activity of alveolar macrophages against Klebsiella pneumoniae through the activation of NADPH oxidase
Blood, August 1, 2005; 106(3): 1067 - 1075.
[Abstract] [Full Text] [PDF]

S. S. T. Lee, W.-Y. Chan, C. K. C. Lo, D. C. C. Wan, D. S. C. Tsang, and W.-T. Cheung
Requirement of PPAR{alpha} in maintaining phospholipid and triacylglycerol homeostasis during energy deprivation
J. Lipid Res., November 1, 2004; 45(11): 2025 - 2037.
[Abstract] [Full Text] [PDF]

C. Brink, S.-E. Dahlen, J. Drazen, J. F. Evans, D. W. P. Hay, G. E. Rovati, C. N. Serhan, T. Shimizu, and T. Yokomizo
International Union of Pharmacology XLIV. Nomenclature for the Oxoeicosanoid Receptor
Pharmacol. Rev., March 1, 2004; 56(1): 149 - 157.
[Abstract] [Full Text] [PDF]

J. D. Walters and R. J. Nakkula
Ciprofloxacin Transport by Chemoattractant-Activated Polymorphonuclear Leukocytes: Regulation by Priming and Protein Kinase C
Antimicrob. Agents Chemother., October 1, 2003; 47(10): 3345 - 3348.
[Abstract] [Full Text] [PDF]

G. Paragh, E. Kovács, I. Seres, T. Keresztes, Z. Balogh, J. Szabó, F. Teichmann, and G. Fóris
Altered signal pathway in granulocytes from patients with hypercholesterolemia
J. Lipid Res., September 1, 1999; 40(9): 1728 - 1733.
[Abstract] [Full Text]

N. Geijsen, S. van Delft, J. A.M. Raaijmakers, J.-W. J. Lammers, J. G. Collard, L. Koenderman, and P. J. Coffer
Regulation of p21rac Activation in Human Neutrophils
Blood, August 1, 1999; 94(3): 1121 - 1130.
[Abstract] [Full Text] [PDF]

B. Settmacher, D. Bock, H. Saad, S. Gartner, C. Rheinheimer, J. Kohl, W. Bautsch, and A. Klos
Modulation of C3a Activity: Internalization of the Human C3a Receptor and its Inhibition by C5a
J. Immunol., June 15, 1999; 162(12): 7409 - 7416.
[Abstract] [Full Text] [PDF]

J. T. O'Flaherty, B. A. Chadwell, M. W. Kearns, S. Sergeant, and L. W. Daniel
Protein Kinases C Translocation Responses to Low Concentrations of Arachidonic Acid
J. Biol. Chem., June 29, 2001; 276(27): 24743 - 24750.
[Abstract] [Full Text] [PDF]