Leland H. Hartwell

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Leland "Lee" Harrison Hartwell (born October 30, 1939 in Los Angeles ) is an American biologist, biochemist , molecular geneticist and cancer researcher.

In 2001, he and Tim Hunt and Paul M. Nurse received the Nobel Prize in Physiology or Medicine for the discovery of key regulators for the process of cell division . He was the director of the Fred Hutchinson Cancer Research Center at the University of Washington in Seattle .

Life

Even as a child, Hartwell showed a keen interest in biology, combined with a desire for a thorough understanding of the phenomena observed. He was the first in his family to study, initially physics, but soon switched to biology. After graduating from the California Institute of Technology , he moved to the Massachusetts Institute of Technology at the Institute of Boris Magasanik, where he received his PhD in 1964. His doctoral thesis was: "Studies on the induction of histidase in Bacillus subtilis".

After further research at the Salk Institute for Biological Studies , he moved to an assistant professorship at the University of California, Irvine in 1965 and to the University of Washington in Seattle in 1968, where he became a professor of genetics in 1973. From 1997 to 2010 he was director of the Fred Hutchinson Cancer Research Center there .

Discoveries about the process of cell division

Shortly after completing his doctorate, Hartwell decided to use genetic methods he had been studying since the late 1960s to study the mechanisms of cell division . Although even then he was striving to apply his research results to the fight against cancer, he chose yeast cells ( Saccharomyces cerevisiae ) as the object of investigation, since working with them was methodologically easier than with human cell cultures . Through elegant mutation experiments, he succeeded in identifying a sequence of over 100 genes that regulate cell division, which he called CDC genes (" cell division cycle genes").

Cell division process

The cell division process shown in the figure is divided into the four main phases G1 = growth of the cell, S = synthesis of DNA, G2 = duplication of DNA and M = mitosis or division into separate cells. Hartwell succeeded in identifying the more than 100 CDC genes responsible for the time-coordinated processes. One of them, CDC-28, is responsible for starting cell division. It is controlled by various CDK molecules (CDK = cyclin dependent kinase) and cyclins, the discovery of which the other two physiology and 2001 Nobel Prize winners in medicine were honored.

Remarkably, these mechanisms are largely independent of the type of organism. The control mechanisms elucidated in yeast cells are exactly the same as in human cells. For tumor diagnosis and therapy, the knowledge found by Hartwell opens up new opportunities for molecular biology , which are currently being investigated by many research groups around the world.

Academic awards

literature

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