The ‘mitoflash’ probe cpYFP does not respond to superoxide

• Published in: Nature (London) Vol. 514; no. 7523; pp. E12 - E14
• Main Authors: Schwarzländer, Markus, Wagner, Stephan, Ermakova, Yulia G., Belousov, Vsevolod V., Radi, Rafael, Beckman, Joseph S., Buettner, Garry R., Demaurex, Nicolas, Duchen, Michael R., Forman, Henry J., Fricker, Mark D., Gems, David, Halestrap, Andrew P., Halliwell, Barry, Jakob, Ursula, Johnston, Iain G., Jones, Nick S., Logan, David C., Morgan, Bruce, Müller, Florian L., Nicholls, David G., Remington, S. James, Schumacker, Paul T., Winterbourn, Christine C., Sweetlove, Lee J., Meyer, Andreas J., Dick, Tobias P., Murphy, Michael P.
• Format: Journal Article
• Language: English
• Published: London Nature Publishing Group UK 23-10-2014; Nature Publishing Group
• Subjects: 14; 14/10; 14/35; 631/1647/1888/2249; 631/443/7; 631/57/1464; 631/80/642/333/1465; Animals; brief-communications-arising; Caenorhabditis elegans - metabolism; Cell metabolism; Cell research; Cellular control mechanisms; Health aspects; Humanities and Social Sciences; Life Sciences; Longevity; Male; Mitochondria - metabolism; multidisciplinary; Science; Superoxide; Superoxides - metabolism; Yellow fluorescent proteins; PH; SIGNALS; FLASHES; MITOCHONDRIAL SUPEROXIDE
• ISSN: 0028-0836; 1476-4687
• DOI: 10.1038/nature13858

Arising from
E.-Z. Shen
et al.
Nature508, 128–132 (2014); doi:10.1038/nature1301210.1038/nature13012
Ageing and lifespan of organisms are determined by complicated interactions between their genetics and the environment, but the cellular mechanisms remain controversial; several studies suggest that cellular energy metabolism and free radical dynamics affect lifespan, implicating mitochondrial function. Recently, Shen
et al.
1
provided apparent mechanistic insight by reporting that mitochondrial oscillations of ‘free radical production’, called ‘mitoflashes’, in the pharynx of three-day old
Caenorhabditis elegans
correlated inversely with lifespan. The interpretation of mitoflashes as ‘bursts of superoxide radicals’ assumes that circularly permuted yellow fluorescent protein (cpYFP) is a reliable indicator of mitochondrial superoxide
2
, but this interpretation has been criticized because experiments and theoretical considerations both show that changes in cpYFP fluorescence are due to alterations in pH, not superoxide
3
,
4
,
5
,
6
,
7
. Here we show that purified cpYFP is completely unresponsive to superoxide, and that mitoflashes do not reflect superoxide generation or provide a link between mitochondrial free radical dynamics and lifespan. There is a Reply to this Brief Communication Arising by
Cheng, H. et al.
Nature
514,
http://dx.doi.org/10.1038/nature13859
(2014).