Osamu Shimomura (1928–2018) Chemist Who Illuminated Bioluminescence

OBITUARY COMMENT Osamu Shimomura (1928–2018) Chemist who illuminated bioluminescence.

rowing up during one of Shimomura, his family and his the darkest times in history, research colleagues spent 19 sum Osamu Shimomura devoted mers at Friday Harbor, collecting Ghis long and fruitful career to under hundreds of thousands of jellyfish to standing how creatures emit light. obtain enough of the elusive material He discovered green fluorescent pro for a full structural analysis. Until a tein (GFP), with which — decades way of making genetically engi later — biomedical researchers neered aequorin became available in began to monitor the workings of the 1990s, Shimomura freely shared proteins in living tissue, and to con his carefully harvested stocks with firm the insertion of genes. For that laboratories the world over. discovery, he shared the Nobel Prize It was in the process of purifying in Chemistry in 2008 with neuro aequorin that Shimomura discov biologist Martin Chalfie and the late ered small amounts of GFP, which Roger Tsien, a chemist. fluoresces green when aequorin Shimomura, who died in emits its blue light. It took him and Nagasaki, Japan, on 19 October, was his team until 1979 to accumulate

MARINE BIOLOGICAL LABORATORY/TOM KLEINDINST LABORATORY/TOM MARINE BIOLOGICAL the first to show that a protein could enough to explore how the protein contain the light-emitting appara works. Shimomura described GFP’s tus within its own peptide chain, rather than the laboratory of organic chemist Yoshimasa unprecedented incorporation of the light- interacting with a separate light-emitting Hirata at Nagoya University, and his lifelong emitting function within the protein chain compound. The significance of this discov fascination with bioluminescence began. (O. Shimomura FEBS Lett. 104, 220–222; ery was that the gene encoding GFP could, Hirata asked him to extract and purify 1979), and then put GFP aside to work on in principle, be copied (or ‘cloned’) and used a compound, luciferin, which enables the wide-ranging studies of bioluminescence in as a tool in other organisms. Others eventu tiny marine crustacean Cypridina to glow other organisms. ally took that step, but it would have been in the dark. Hirata thought the results too In 1994, Chalfie’s group reported the suc impossible without the exemplary patience uncertain for a PhD student, but because cessful creation of bacteria and roundworms of Shimomura, who spent years gathering Shimomura was not registered for a degree, that could express GFP (M. Chalfie et al. Sci- enough material to extract, purify and deter he allowed him to try. In just ten months, ence 263, 802–805; 1994). Soon afterwards, mine the chemical structure of GFP. Shimomura made pure crystals of luciferin Tsien and his colleagues created GFPs of dif Born on 27 August 1928 in the town of (O. Shimomura et al. Bull. Chem. Soc. Japan ferent colours (R. Heim et al. Nature 373, Fukuchiyama, at the height of Japanese 30, 929–933; 1957). “I learned that any dif 663–664; 1995). Others have extended the expansionism, Shimomura was the son of ficult problem can be solved by great effort,” technique to vertebrates, with headlines an army captain whose frequent postings he wrote in his Nobel biography. about ‘glow-in-the-dark monkeys’ obscur abroad disrupted his child’s school educa The luciferin paper brought an invitation ing the method’s great value in confirming tion. Shimomura’s grandmother instilled in for Shimomura to join the bioluminescence the successful incorporation of genes from him the samurai principles of honour and lab of biologist Frank Johnson at Princeton other organisms. fortitude. In 1944, with the Pacific War turn University in New Jersey. Three weeks after From 1982 until his retirement in 2001, ing against Japan, he and his fellow school marrying Akemi Okubo in August 1960, Shimomura moved to the Woods Hole students were mobilized to work in a muni Shimomura sailed to the United States, his Marine Biological Laboratory in Massa tions factory in Isahaya, about 25 kilometres travel paid for by a Fulbright scholarship. chusetts with Akemi, who had continued from Nagasaki. On 9 August 1945, he was Johnson asked him to work on the jellyfish to work as his research assistant. After their at work when a blinding flash, followed by Aequorea, which has a ring of organs around retirement — a concept that was clearly a huge pressure wave, signalled the drop the edge of its umbrella that emit blue light. difficult for them — they moved their ping of the atomic bomb on the nearby city. In July 1961, Johnson, Shimomura and his laboratory into their home and continued He walked home under a shower of black wife, and several assistants and students to work. Shimomura’s textbook Biolumines- rain. He later wrote that his grandmother’s made a road trip across the United States to cence: Chemical Principles and Methods was quick action in putting him straight in the collect hundreds of jellyfish, scooping them released in 2006, and in 2017 he published an bath might have saved him from the effects out of Friday Harbor in Washington state, autobiography, Luminous Pursuit: Jellyfish, of the radiation. cutting off the rings and transporting them GFP, and the Unforeseen Path to the Nobel Without a high-school diploma, he to Princeton for analysis. Prize. ■ despaired of finding a college place. Eventu In the face of scepticism from Johnson ally, Nagasaki Pharmacy College admitted and others, Shimomura determined that Georgina Ferry is a science writer him in 1948. On graduation, he worked for the luminescent substance was a protein; he specializing in the history of the life sciences four years as an assistant in practical classes. named it aequorin. He discovered almost in Oxford, UK. Her many books include He devised research projects in his own time, at once that it was activated by calcium biographies of the crystallographers Dorothy and his professor obtained permission for (later, aequorin became an essential reagent Hodgkin and Max Perutz. him to do a year of advanced study. He joined as a glowing marker of calcium release). e-mail: [email protected]