Abstract
The ATP-driven Plasma Membrane Calcium pump or Ca2+-ATPase (PMCA) is characterized by a high affinity for calcium and a low transport rate compared to other transmembrane calcium transport proteins. It plays a crucial role for calcium extrusion from cells. Calmodulin is an intracellular calcium buffering protein which is capable in its Ca2+ liganded form of stimulating the PMCA by increasing both the affinity to calcium and the maximum calcium transport rate. We introduce a new model of this stimulation process and derive analytical expressions for experimental observables in order to determine the model parameters on the basis of specific experiments. We furthermore develop a model for the pumping activity. The pumping description resolves the seeming contradiction of the Ca2+:ATP stoichiometry of 1:1 during a translocation step and the observation that the pump binds two calcium ions at the intracellular site. The combination of the calcium pumping and the stimulation model correctly describes PMCA function. We find that the processes of calmodulin-calcium complex attachment to the pump and of stimulation have to be separated. Other PMCA properties are discussed in the framework of the model. The presented model can serve as a tool for calcium dynamics simulations and provides the possibility to characterize different pump isoforms by different type-specific parameter sets.
Keywords: plasma membrane calcium pump, plasma membrane Ca2+-ATPase, calmodulin, stimulation, relaxation, pumping activity, theoretical model, parameter
Full Text
The Full Text of this article is available as a PDF (1.5 MB).
References
- Zylinska L., Soszynski M. Plasma Membrane Ca2+-ATPase in Excitable and Nonexcitable Cells. Acta Biochim. Pol. 2000;47:529. [PubMed] [Google Scholar]
- Penniston J.T., Enyedi A. Modulation of the Plasma Membrane Ca2+ Pump. J. Membr. Biol. 1998;165:101. doi: 10.1007/s002329900424. [DOI] [PubMed] [Google Scholar]
- Carafoli E. The Calcium Pumping ATPase of the Plasma Membrane. Annu. Rev. Physiol. 1991;53:531. doi: 10.1146/annurev.ph.53.030191.002531. [DOI] [PubMed] [Google Scholar]
- Juhaszova M., Church P., Blaustein M.P., Stanley E.F. Location of Calcium Transporters at Presynaptic Terminals. Eur. J. Neurosci. 2000;12:839. doi: 10.1046/j.1460-9568.2000.00974.x. [DOI] [PubMed] [Google Scholar]
- Guerini D. The Significance of the Isoforms of Plasma Membrane Calcium ATPase. Cell Tissue Res. 1998;292:191. doi: 10.1007/s004410051050. [DOI] [PubMed] [Google Scholar]
- Stauffer T.P., Guerini D., Carafoli E. Tissue Distribution of the Four Gene Products of the Plasma Membrane Calcium Pump. J. Biol. Chem. 1995;270:12184. doi: 10.1074/jbc.270.11.6056. [DOI] [PubMed] [Google Scholar]
- Carafoli E. The Ca2+ Pump of the Plasma Membrane. J. Biol. Chem. 1992;267:2115. [PubMed] [Google Scholar]
- Chin D., Means A.R. Calmodulin: A Prototypical Calcium Sensor. Trends Cell Biol. 2000;10:322. doi: 10.1016/S0962-8924(00)01800-6. [DOI] [PubMed] [Google Scholar]
- Caride A.J., Penheiter A.R., Filoteo A.G., Bajzer Z., Enyedi A., Penniston J.T. The Plasma Membrane Calcium Pump Displays Memory of Past Calcium Spikes. J. Biol. Chem. 2001;276:39797. doi: 10.1074/jbc.M104380200. [DOI] [PubMed] [Google Scholar]
- Linse S., Helmersson A., Forsen S. Calcium Binding to Calmodulin and its Globular Domains. J. Biol. Chem. 1991;266:8050. [PubMed] [Google Scholar]
- Pottorf W.J., Duckles S.P., Buchholz J.N. Mechanisms of Calcium Buffering in Adrenergic Neurones and Effects of Ageing: Testing the Limits of Homeostasis. J. Auton. Pharmacol. 2000;20:63. doi: 10.1046/j.1365-2680.2000.00165.x. [DOI] [PubMed] [Google Scholar]
- Persechini A., Cronk B. The Relationship Between the Free Concentrations of Ca2+ and Ca2+-Calmodulin in Intact Cells. J. Biol. Chem. 1999;274:6827. doi: 10.1074/jbc.274.11.6827. [DOI] [PubMed] [Google Scholar]
- Meyer T., Hanson P.I., Stryer L., Schulman H. Calmodulin Trapping by Calcium-Calmodulin-Dependent Protein Kinase. Science. 1992;256:1199. doi: 10.1126/science.256.5060.1199. [DOI] [PubMed] [Google Scholar]
- Persechini A., Yano K., Stemmer P.M. Ca2+ Binding and Energy Coupling in the Calmodulin-Myosin Light Chain Kinase Complex. J. Biol. Chem. 2000;275:4199. doi: 10.1074/jbc.275.6.4199. [DOI] [PubMed] [Google Scholar]
- Elwess N.L., Filoteo A.G., Enyedi A., Penniston J.T. Plasma Membrane Ca2+ Pump Isoforms 2a and 2b are Unusually Responsive to Calmodulin and Ca2+ J. Biol. Chem. 1997;272:17981. doi: 10.1074/jbc.272.29.17981. [DOI] [PubMed] [Google Scholar]
- Penheiter A.R., Zeljko B., Filoteo A.G., Thorogate R., Török K., Caride A.J. A Model of the Activation of Plasma Membrane Calcium Pump Isoform 4b by Calmodulin. J. Bio. Chem. 2003;42:12115. doi: 10.1021/bi027098+. [DOI] [PubMed] [Google Scholar]
- Caride A.J., Filoteo A.G., Elwess N.L., Verma A.K., Enyedi A., Bajzer Z., Penniston J.T. The Rate of Activation by Calmodulin of Isoform 4 of the Plasma Membrane Ca2+ Pump is Slow and is Changed by Alternative Splicing. J. Biol. Chem. 1999;274:35227. doi: 10.1074/jbc.274.49.35227. [DOI] [PubMed] [Google Scholar]
- Enyedi A., Filoteo A.G., Gardos G., Penniston J.T. Calmodulin-Binding Domains from Isozymes of the Plasma Membrane Calcium Pump have Different Regulatory Properties. J. Biol. Chem. 1991;266:8952. [PubMed] [Google Scholar]
- Ba-Thein W., Caride A.J., Filoteo A.G., Enyedi A., Paszty K., Croy C.L., Penniston J.T. Chimaeras Reveal the Role of the Catalytic Core in the Activation of the Plasma Membrane Ca2+ Pump. Biochem. J. 2001;356:241. doi: 10.1042/0264-6021:3560241. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Penheiter A.R., Caride A.J., Enyedi A., Penniston J.T. Tryptophan 1093 is Largely Responsible for the Slow off Rate off Calmodulin from Plasma Membrane Calcium Pump 4b. J. Biol. Chem. 2002;277:17728. doi: 10.1074/jbc.M111608200. [DOI] [PubMed] [Google Scholar]
- Caride A.J., Filoteo A.G., Penheiter A.R., Paszty K., Enyedi A., Penniston J.T. Delayed Activation of the Plasma Membrane Calcium Pump by a Sudden Increase in Ca2+: Fast Pumps Reside in Fast Cells. Cell Calcium. 2001;30:49. doi: 10.1054/ceca.2001.0212. [DOI] [PubMed] [Google Scholar]
- Lytton J., Westlin M., Burk S.E., Shull G.E., MacLennan D.H. Functional Comparisions Between Isoforms of the Sacroplasmic or Endoplasmic Reticulum Family of Calicum Pumps. J. Biol. Chem. 1992;267:14483. [PubMed] [Google Scholar]
- Verma A.K., Enyedi A., Filoteo A.G., Strehler E.E., Penniston J.T. Plasma Membrane Calcium Pump Isoform 4a has a Longer Calmodulin-Binding Domain than 4b. J. Biol. Chem. 1996;271:3713. doi: 10.1074/jbc.271.50.32461. [DOI] [PubMed] [Google Scholar]
- Hilfiker H., Guerini D., Carafoli E. Cloning and Expression of the Isoform 2 of the Human Plasma Membrane Ca2+ ATPase. J. Biol. Chem. 1994;269:26178. [PubMed] [Google Scholar]
- Adamo H.P., Grimaldi M.E. Functional Consequences of Relocation the C-terminal Calmodulin-binding Autoinhibitory Domains of the Plasma Membrane Ca2+ Pump near the N-terminus. Biochem. J. 1998;331:763. doi: 10.1042/bj3310763. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Hudmon A., Schulman H. Neuronal Ca2+/Calmodulin-Dependent Protein Kinase II: The Role of Structure and Autoregulation in Cellular Function. Annu. Rev. Biochem. 2002;71:473. doi: 10.1146/annurev.biochem.71.110601.135410. [DOI] [PubMed] [Google Scholar]
- Olwin B.B., Edelman A.M., Krebs E.G., Strom D.R. Quantitation of Energy Coupling Between Ca2+, Calmodulin, Skeletal Muscle Myosin Light Chain Kinase, and Kinase Substrates. J. Biol. Chem. 1984;259:10949. [PubMed] [Google Scholar]
- Guerini D., Zecca-Mazza A., Carafoli E. Single Amino Acid Mutations in Transmembrane Domain 5 Confer to the Plasme Membrane Ca2+ Pump Properties Typical of the Ca2+ Pump of Endo(sacro)plasmic Reticulum. J. Bio. Chem. 2000;275:31361. doi: 10.1074/jbc.M003474200. [DOI] [PubMed] [Google Scholar]
- Adamo H., Rega A., Garrahan P. Pre-Steady-State Phosphorylation of the Human Red Cell Ca2+-ATPase. J. Bio. Chem. 1988;263:17548. [PubMed] [Google Scholar]