Japanese scientists produce bright and photostable green fluorescent protein from jellyfish

The problem is that a fluorescent protein's brightness rapidly decreases under intense light due to a process called photobleaching. The trade-off between brightness and photostability further complicates issues because enhancing one will almost always result in a decrease in the other.

10 times more photostable

A fluorescent protein that defies this trade-off relationship has been developed by Atsushi Miyawaki of the RIKEN Center for Brain Science and his colleagues. It provides great brightness while being around 10 times more photostable than the best commercial fluorescent proteins.

Named StayGold, the fluorescent protein is derived from a naturally occurring fluorescent protein found in Cytaeis uchidae, a tiny jellyfish found off the coast of Japan.

"We noticed that the fluorescent protein from the jellyfish was photostable but very dim. And I wasn’t optimistic about making the protein brighter while keeping that photostability because I simply believed the tradeoff,” said Miyawaki in the statement.

“However, to our surprise, we were able to increase both the protein’s photostability and its brightness. So we could have our cake and eat it too.”

44 thousand people could have accessed it

The scientists used StayGold to photograph the endoplasmic reticulum network and mitochondria in cells with improved spatiotemporal resolution and length of observation, demonstrating its applicability.

The report has drawn a great deal of interest, as evidenced by the fact that over 44 thousand people have accessed it since it was published in late April. The RIKEN BioResource Research Center has the protein available for researchers who want to experiment with it.

Miyawaki and his team plan to look into the mechanism underlying that StayGold can be brilliant and keep bright under illumination.

Abstract

The low photostability of fluorescent proteins is a limiting factor in many applications of fluorescence microscopy. Here we present StayGold, a green fluorescent protein (GFP) derived from the jellyfish Cytaeis Uchida. StayGold is over one order of magnitude more photostable than any currently available fluorescent protein and has a cellular brightness similar to neon green. We used StayGold to image the dynamics of the endoplasmic reticulum (ER) with high spatiotemporal resolution over several minutes using structured illumination microscopy (SIM) and observed substantially less photobleaching than with a GFP variant optimized for stability in the ER. Using StayGold fusions and SIM, we also imaged the dynamics of mitochondrial fusion and fission and mapped the viral spike proteins in fixed cells infected with severe acute respiratory syndrome coronavirus 2. As StayGold is a dimer, we created a tandem dimer version that allowed us to observe the dynamics of microtubules and the excitatory post-synaptic density in neurons. StayGold will substantially reduce the limitations imposed by photobleaching, especially in the live cell or volumetric imaging.