- Person
- Howard Temin
- Lived
- 1934–1994
- Field
- Virology, cancer research
- From
- American
The story
Howard Temin, born in 1934 to a Jewish family in Philadelphia, studied Rous sarcoma virus, which causes cancer in chickens, first at Caltech and then at the University of Wisconsin. The virus carries its genes as RNA, yet the cells it transforms pass the change to all their descendants, as if the viral genes had become a permanent part of the cell’s DNA. By 1964 Temin had proposed his provirus hypothesis: the virus’s RNA is copied into DNA, which then lodges in the cell’s chromosomes.
Most scientists rejected the idea. The central dogma of molecular biology, as commonly understood, held that genetic information flows only from DNA to RNA to protein, never backwards. For six years Temin persisted, with a small laboratory that had started in a basement. In 1969 he and his postdoctoral fellow Satoshi Mizutani began searching virus particles for the enzyme that would do the copying.
They found it. At the same time, David Baltimore at MIT independently found the same enzyme in a mouse leukaemia virus, and both papers appeared in the same issue of Nature on June 27, 1970. The enzyme, reverse transcriptase, builds DNA from an RNA template, and the viruses that use it became known as retroviruses. In 1975 Temin, Baltimore and Renato Dulbecco shared the Nobel Prize in Physiology or Medicine.
A decade later, the virus that causes AIDS was identified as a retrovirus that depends on reverse transcriptase to infect human cells. Because scientists already understood the enzyme, it became the first target for AIDS drugs. Zidovudine, or AZT, a reverse transcriptase inhibitor, was approved in the United States in March 1987 as the first antiretroviral medicine and is on the World Health Organization’s List of Essential Medicines. Reverse transcriptase inhibitors remain a mainstay of HIV treatment, and the enzyme itself became an essential laboratory tool for studying genes.
Why it matters
Reverse transcriptase inhibitors, built on Temin’s discovery, are a mainstay of the HIV treatment that keeps millions of people alive, and the enzyme is a basic tool of genetic research and testing.
About Howard Temin
Wisconsin virologist who defied orthodoxy to show that some viruses copy their genes into DNA, co-discovering reverse transcriptase, the target of HIV drugs. Nobel Prize 1975.
Sources
- Howard M. Temin, Biographical NobelPrize.org
- Howard Martin Temin Wikipedia
- Zidovudine Wikipedia
- Scientist of the Day: Howard Temin Linda Hall Library
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