The recent identification of a poppy plant gene has brought researchers one step closer to making morphine in the lab rather than in fields. The protein the gene codes for, called STORR, was described on 25 June in Science and represents the last cog in the enzymatic machinery required to engineer yeast to produce morphine.
“The publication of this gene provides the missing link for the production of morphine in yeast — there&’s no doubt about it,” study co-author Ian Graham, a geneticist at the Center for Novel Agricultural Products at the University of York, told the Los Angeles Times. “I think it&’s only a matter of time before there is a proof-of-concept demonstration in yeast that this can happen.”
Researchers at the University of York and GlaxoSmithKline in Australia identified STORR by screening randomly-generated mutant poppy plants for their ability to make morphine. Plants with mutations in the gene encoding STORR were unable to make the opioid since, as the researchers discovered, STORR performs a key step in morphine biosynthesis by isomerising a morphine precursor called reticuline. The team also reported that STORR was a fusion product of two genes encoding an oxidase and a reductase enzyme.
“Plants produce an amazing array of natural chemicals,” Graham said. “The discovery of this STORR gene fusion provides us with new insight into how poppy plants have evolved to produce the most effective painkillers known to man.”
But the discovery is also adding to concerns that it may soon be possible to produce “home-brewed” heroin. “You can see how quickly the technical challenges are being overcome, even faster than we anticipated,” Tania Bubela, a researcher at the University of Alberta School of Public Health who was not involved with the study, said. “It speaks to the fact that policymakers need to get ahead of the technology.”
Amanda B Keener/The Scientist