Mitochondrial uncoupling does not influence the stability of the intracellular signal activating plasma membrane calcium channels.

• Authors: Krzysztof Zabłocki , Agnieszka Makowska , Jerzy Duszyński
• Languages of publication: EN

Abstracts

EN

The effects of various concentrations of thapsigargin, a specific inhibitor of Ca2+-ATPase in the endoplasmic reticulum (ER) membrane, on calcium homeostasis in lymphoidal T cells (Jurkat) were investigated. Preincubation of these cells suspended in nominally calcium-free medium with 0.1 μM thapsigargin resulted in a complete release of Ca2+ from intracellular calcium stores. When the medium was supplemented with 3 mM CaCl2 the cells maintained constantly elevated level of cytosolic Ca2+. However, thapsigargin applied at lower concentration produced only a partial depletion of the stores. For example, in the cells pretreated with 1 nM thapsigargin and suspended in calcium-free medium approximately 75% of the calcium content was released from the intracellular stores. The addition of 3 mM CaCl2 to such cell suspension led to a transient increase in cytosolic calcium concentration, followed by a return to a lower steady-state. This phenomenon, related to the refilling of the ER by Ca2+, allowed to estimate the half-time for the process of cell recovery after activation of store-operated calcium channels. By this approach we have found that carbonyl cyanide m-chlorophenylhydrazone, which has been documented to inhibit calcium entry into Jurkat cells, does not influence the stability of the intracellular signal involved in the activation of store-operated calcium channels.

Keywords

EN

Jurkat cells; store-operated calcium entry; mitochondrial uncoupling; thapsigargin

• Publisher: Polish Biochemical Society
• Journal: Acta Biochimica Polonica
• Year: 2001
• Volume: 48
• Issue: 1
• Pages: 157-161

Dates

published

2001

received

2001-02-15

accepted

2001-02-17

Contributors

author

Krzysztof Zabłocki

• Department of Cellular Biochemistry, Nencki Institute of Experimental Biology, Warszawa, Poland

author

Agnieszka Makowska

• Department of Cellular Biochemistry, Nencki Institute of Experimental Biology, Warszawa, Poland

author

Jerzy Duszyński

• Department of Cellular Biochemistry, Nencki Institute of Experimental Biology, Warszawa, Poland

References

• Barrit, G.J. (1999) Receptor-activated Ca2+ inflow in animal cells: A variety of pathways tailored to meet different intracellular Ca2+ signalling requirements. Biochem. J. 337, 153-169.
• Berridge, M.J. (1995) Capacitative calcium entry. Biochem. J. 312, 1-11.
• Fernando, C.K., Gregory, R.B. & Barritt, G.J. (1998) Protein kinase A regulates the disposition of Ca2+ which enters the cytoplasmic space through store- activated Ca2+ channels in rat hepatocytes by diverting inflowing Ca2+ to mitochondria. Biochem. J. 267, 877-884.
• Gamberucci, A., Innocenti, B., Fulceri, R., Banhegy, G., Giunti, R. & Benedetti, A. (1994) Modulation of Ca2+ influx dependent on store depletion by intracellular adenine-guanine nucleotide levels. J. Biol. Chem. 269, 23597-23602.
• Grynkiewicz, G., Poenie, M. & Tsien, R.Y. (1985) A new generation of Ca2+ indicators with greatly improved fluorescence properties. J. Biol. Chem. 260, 3440-3450.
• Hofer, A.M., Fasolato, C. & Pozzan, T. (1998) Capacitative Ca2+ entry is closely linked to the filling state of internal Ca2+ stores: A study using simultaneous measurements of ICRAC and intraluminal [Ca2+]. J. Cell Biol. 140, 325-334.
• Hoth, M., Fanger, C.M. & Lewis, R.S. (1997) Mitochondrial regulation of store-operated calcium signaling in T lymphocytes. J. Cell Biol. 137, 633-648.
• Kiselyov, K., Xu, X., Mozhayeva, G., Kuo, T., Pessah, I., Mignery, G., Zhu, X., Birnbaumer, L. & Muallem, S. (1998) Functional interaction between InsP3 receptors and store-operated Htrp3 channels. Nature 396, 478-482.
• Makowska, A., Zabłocki, K. & Duszyński, J. (2000) the role of mitochondria in the regulation of calcium influx into Jurkat cells. Eur. J. Biochem. 267, 877-884.
• Parekh, A.B. (1998) Slow feedback inhibition of calcium release-activated calcium current by calcium entry. J. Biol. Chem. 273, 14925-14932.
• Parekh, A.B. & Penner, R. (1997) Store depletion and calcium influx. Physiol. Rev. 77, 901-929.
• Putney, J.W. (1986) A model for receptor-regulated calcium entry. Cell Calcium 7, 1-12.
• Putney, J.W. (1990) Capacitative calcium entry revisited. Cell Calcium 11, 611-624.
• Thastrup, O., Dawson, A.P., Scharff, O., Foder, B., Cullen, P.J. Drobak, B.K., Bjerrum, P.J., Christensen, S.B. & Hanley, M.R. (1994) Thapsigargin, a novel molecular probe for studying intracellular calcium release and storage. Agents Actions 43, 187-193.
• Waśniewska, M. & Duszyński, J. (2000) The role of mitochondrial dysfunction in regulation of store-operated calcium channels in glioma C6 and human fibroblast cells. FEBS Lett. 478, 237-240.
• Zweifach, A. & Lewis, R.S. (1995a) Slow calcium-dependent inactivation of depletion-activated calcium current. Store-dependent and -independent mechanisms. J. Biol. Chem. 270, 14445- 14451.
• Zweifach, A. & Lewis, R.S. (1995b) Rapid inactivation of depletion-activated calcium current (ICRAC) due to local calcium feedback. J. Gen. Physiol. 105, 209-226.