Harvard Scientists Discovery Opens Door to Synthetic Life
Researchers led by George Church, whose findings helped spur the U.S. human genome project in the 1980s, have copied the part of a living cell that makes proteins, the building blocks of life. The finding overcomes a major roadblock in making synthetic self-replicating organisms, Church said today in a lecture at Harvard in Cambridge, Massachusetts.
The technology can be used to program cells to make virtually any protein, even some that dont exist in nature, the scientists said. That may allow production of helpful new drugs, chemicals and organisms, including living bacteria. It also opens the door to ethical concerns about creation of processes that may be uncontrollable by lifes natural defenses.
“Its the key component to making synthetic life,” Church said yesterday in a telephone call with reporters. “We havent made synthetic life and its not our primary goal, but this is a huge milestone in that direction.”
The work may be immediately helpful to companies such as Synthetic Genomics Inc., headed by J. Craig Venter, trying to make new organisms that perform specific tasks, such as converting buried coal into methane gas thats easier to extract from the ground.
Microbes for Coal
Venters plan is to create man-made microbes that can help break down the coal in the earth, much as bacteria speed decomposing plant material.
In a conference for alumni today at Harvard, Church described how his team assembled a reconstituted ribosome, the first artificial version of the structure capable of remaking itself.
Naturally occurring ribosomes are used now when biotechnology companies genetically engineer cells to make the proteins for vaccines and drugs, such as Genentech Inc.s Herceptin. Normal ribosomes make some drugs slowly, and others cant be made at all, said Anthony Forster, a Vanderbilt University pharmacologist who has collaborated with Church on synthetic biology projects.
A man-made, or reconstituted, ribosome may be programmable to make all kinds of molecules, Forster said.
Efficient Protein Making
“There would be advantages to having ribosomes that would only make specific proteins” said James Collins, a Boston University biomedical engineer, in a telephone interview. “Then you could program ribosomes so that they shut down much of the rest of the cell, only making the proteins you want to produce. You could shift the cells machinery to making certain products or fuels, for example, and really increase efficiency.”
“They would have a longer stability in natural environments,” Church said.
Ribosomes have been synthesized before, some as long as 40 years ago. Because they were made only under specialized conditions of temperature and salt concentration, scientists couldnt get them to recreate themselves, a key requirement in making artificial life.
Security Concerns
Artificial life and drugs that cant be broken down by the bodys natural enzymes raise a number of serious concerns, said David Magnus, director of the Stanford Center for Biomedical Ethics.
As the tools of synthetic biology become easier to use, bioterrorists and criminals may attempt to exploit them, he said. Well-meaning scientists might also release potentially deadly organisms and chemicals into the environment.
“A number of proposals have been made about controlling access to this technology,” Magnus said in a telephone interview. “The synthetic biology community takes these issues seriously and are talking about what it will take to make sure we have effective oversight.”
The first artificial organisms are likely to be grown in highly controlled conditions, and would probably be unable to exist outside the laboratory, said Vanderbilts Forster.