Temin, Howard Martin (1934-1994), an American molecular biologist, did important research on how some viruses affect cancer cells. For his work, Temin shared the 1975 Nobel Prize for physiology or medicine with fellow Americans David Baltimore and Renato Dulbecco (see Baltimore, David ; Dulbecco, Renato ).
Temin discovered that an RNA virus, which has a core of genetic material called RNA (ribonucleic acid), could not infect a cell once the cell’s synthesis of DNA (deoxyribonucleic acid) was stopped. Temin formed a possible explanation for what he had observed called the provirus hypothesis, claiming that the RNA of an invading virus is somehow copied or translated into the DNA of the host cell. As a result, the reproductive activity of the cell would be altered, and the cell would become a cancer cell.
Some molecular biologists doubted Temin’s findings, claiming that genetic material only passed from DNA to RNA, and not vice versa. In 1970, Temin and David Baltimore, working independently, proved the provirus hypothesis to be correct by identifying an enzyme called reverse transcriptase. Reverse transcriptase synthesizes cell DNA by turning RNA into double-stranded DNA and allowing it to enter the host cell. Viruses containing reverse transcriptase are known as retroviruses, because they reverse the usual process of passing genetic information from DNA to RNA. Temin’s work has been useful in cloning, genetic engineering, and research on AIDS, which is caused by a retrovirus (see AIDS ).
Temin was born in Philadelphia. He received his Ph.D. in biology at the California Institute of Technology in 1959. He conducted much research at the McArdle Laboratory for Cancer Research, part of the University of Wisconsin-Madison, where he became a professor in 1960.
