Skip to main content
Log in

Mitochondrial Ca2+ uniporter and CaMKII in heart

  • Brief Communications Arising
  • Published:

From Nature

View current issue Submit your manuscript

Abstract

Arising from M. A. Joiner et al. Nature 491, 269–273 (2012); doi:10.1038/nature1023410.1038/nature11444

The influx of cytosolic Ca2+ into mitochondria is mediated primarily by the mitochondrial calcium uniporter (MCU)1, a small-conductance, Ca2+-selective channel2,3,4,5,6—MCU modulates intracellular Ca2+ transients and regulates ATP production and cell death1. Recently, Joiner et al. reported that MCU is regulated by mitochondrial CaMKII, and this regulation determines stress response in heart7. They reported a very large current putatively mediated by MCU that was about two orders of magnitude greater than the MCU current (IMCU) that we previously measured in heart mitochondria3; furthermore, the current traces presented by Joiner et al. showed unusually high fluctuations incompatible with the low single-channel conductance of MCU. Here we performed patch-clamp recordings from mouse heart mitochondria under the exact conditions used by Joiner et al.7, and confirm that IMCU in cardiomyocytes is very small and is not directly regulated by CaMKII; thus, the currents presented by Joiner et al. do not appear to correspond to MCU, and there is no direct electrophysiological evidence that CaMKII regulates MCU. There is a Reply to this Brief Communication Arising by Joiner, M. A. et al. Nature 513, http://dx.doi.org/10.1038/nature13627 (2014).

This is a preview of subscription content, log in via an institution to check access.

Access this article

Price excludes VAT (USA)
Tax calculation will be finalised during checkout.

Instant access to the full article PDF.

Figure 1: Heart MCU current and CaMKII.

Similar content being viewed by others

References

  1. Rizzuto, R., Bernardi, P. & Pozzan, T. Mitochondria as all-round players of the calcium game. J. Physiol. 529, 37–47 (2000)

    Article  CAS  Google Scholar 

  2. Kirichok, Y., Krapivinsky, G. & Clapham, D. E. The mitochondrial calcium uniporter is a highly selective ion channel. Nature 427, 360–364 (2004)

    Article  ADS  CAS  Google Scholar 

  3. Fieni, F., Bae Lee, S., Jan, Y. N. & Kirichok, Y. Activity of the mitochondrial calcium uniporter varies greatly between tissues. Nature Commun. 3, 1317 (2012)

    Article  ADS  Google Scholar 

  4. Chaudhuri, D., Sancak, Y., Mootha, V. K. & Clapham, D. E. MCU encodes the pore conducting mitochondrial calcium currents. eLife 2, e00704 (2013)

    Article  Google Scholar 

  5. De Stefani, D., Raffaello, A., Teardo, E., Szabo, I. & Rizzuto, R. A forty-kilodalton protein of the inner membrane is the mitochondrial calcium uniporter. Nature 476, 336–340 (2011)

    Article  ADS  CAS  Google Scholar 

  6. Baughman, J. M. et al. Integrative genomics identifies MCU as an essential component of the mitochondrial calcium uniporter. Nature 476, 341–345 (2011)

    Article  ADS  CAS  Google Scholar 

  7. Joiner, M. A. et al. CaMKII determines mitochondrial stress responses in heart. Nature 491, 269–273 (2012)

    Article  ADS  CAS  Google Scholar 

  8. Page, E. Quantitative ultrastructural analysis in cardiac membrane physiology. Am. J. Physiol. 235, C147–C158 (1978)

    Article  CAS  Google Scholar 

  9. Smith, H. E. & Page, E. Morphometry of rat heart mitochondrial subcompartments and membranes: application to myocardial cell atrophy after hypophysectomy. J. Ultrastruct. Res. 55, 31–41 (1976)

    Article  CAS  Google Scholar 

  10. Williams, G. S., Boyman, L., Chikando, A. C., Khairallah, R. J. & Lederer, W. J. Mitochondrial calcium uptake. Proc. Natl Acad. Sci. USA 110, 10479–10486 (2013)

    Article  ADS  CAS  Google Scholar 

  11. O'Rourke, B. & Maack, C. The role of Na dysregulation in cardiac disease and how it impacts electrophysiology. Drug Discov. Today Dis. Models 4, 207–217 (2007)

    Article  Google Scholar 

  12. Maack, C. et al. Elevated cytosolic Na+ decreases mitochondrial Ca2+ uptake during excitation-contraction coupling and impairs energetic adaptation in cardiac myocytes. Circ. Res. 99, 172–182 (2006)

    Article  CAS  Google Scholar 

  13. Ashpole, N. M. & Hudmon, A. Excitotoxic neuroprotection and vulnerability with CaMKII inhibition. Mol. Cell. Neurosci. 46, 720–730 (2011)

    Article  CAS  Google Scholar 

  14. Rokita, A. G. & Anderson, M. E. New therapeutic targets in cardiology: arrhythmias and Ca2+/calmodulin-dependent kinase II (CaMKII). Circulation 126, 2125–2139 (2012)

    Article  Google Scholar 

  15. Pusch, M. & Neher, E. Rates of diffusional exchange between small cells and a measuring patch pipette. Pflugers Archiv. 411, 204–211 (1988)

    Article  CAS  Google Scholar 

Download references

Author information

Authors and Affiliations

Authors

Contributions

F.F. and Y.K. conceived the project. F.F. performed electrophysiological experiments. D.E.J. and A.H. generated recombinant CAMKII and determined its activity under various conditions. All authors contributed to experimental design, discussed the results, and wrote the manuscript.

Corresponding author

Correspondence to Yuriy Kirichok.

Ethics declarations

Competing interests

Declared none.

PowerPoint slides

Rights and permissions

Reprints and permissions

About this article

Check for updates. Verify currency and authenticity via CrossMark

Cite this article

Fieni, F., Johnson, D., Hudmon, A. et al. Mitochondrial Ca2+ uniporter and CaMKII in heart. Nature 513, E1–E2 (2014). https://doi.org/10.1038/nature13626

Download citation

  • Received:

  • Accepted:

  • Published:

  • Issue Date:

  • DOI: https://doi.org/10.1038/nature13626

  • Springer Nature Limited

This article is cited by

Navigation