The average human cell contains more than a billion proteins, each of which must travel to a specific location within the cell to do its job. With so many proteins shuttling throughout the cell, it's easy to imagine the molecular mayhem that would result if proteins did not know how to reach their precise destinations.
In a series of groundbreaking experiments conducted over the course of 30 years, Günter Blobel discovered how the cell's protein distribution system operates. It was for this work that he won the Nobel Prize in Physiology or Medicine in 1999. Blobel found that proteins carry built-in signals that act like zip codes to direct proteins to their proper locations within the cell. His studies also demonstrated that special receptors on the surfaces of membranes read those signals and allow the appropriate proteins either to pass through or to lodge within the membrane.
Blobel theorized that proteins had to be transported to membrane-bound structures within the cell called organelles before ultimately being transported out of the cell. Organelles, which are analogous to organs in the body, carry out many diverse functions vital to a cell's existence. Blobel's research showed that each newly made protein has an organelle-specific address that is embedded in the protein's "signal sequence" and is recognized by receptors on the surface of an organelle. Demonstrating first in an organelle called the endoplasmic reticulum and subsequently in other organelles, Blobel discovered that when the signal sequence binds to its receptor, a channel opens in the membrane that allows the protein to enter.
As it turns out, the protein-signaling principles uncovered by Blobel are universal, occurring in yeast, plants, and animals, as well as humans. A number of hereditary diseases have been attributed to errors in these signals and transport mechanisms, including cystic fibrosis and a condition that causes kidney stones to develop in young children. His research has also contributed to the development of a more effective use of cells as "protein factories" for the production of important drugs such as insulin, growth hormone, and erythropoietin, which helps stimulate the production of red blood cells.
Blobel, a cellular and molecular biologist, said he is motivated most by an "almost childlike curiosity to find out how cells work and the ecstatic joy that comes with new discoveries." Today, he is working to understand the trafficking of signals between a cell's nucleus and cytoplasm. Understanding this normal "chatter" may help explain how signal disruptions lead to diseases such as cancer.
A native of Germany, Blobel was born in Waltersdorf, a small village in eastern Germany that is now part of Poland. While his early years were idyllic, his life changed dramatically in 1945 when, at the age of eight, he and his family, including seven brothers and sisters, fled their home to escape the advancing Russian army. Traveling by car to the home of relatives, they passed through the historic town of Dresden, a city known for its magnificent architecture, which made an indelible impression on the young Blobel. Only days later, from the outskirts of Dresden, he witnessed the massive firebombing of the city—a sight that he never forgot.
In the final days of the war, Blobel's oldest sister Ruth was killed during an air raid, and the family was left to live under strict Communist rule in East Germany. The oppressive regime prevented him from attending a university, as Blobel's family was considered to be "upper class." Fortunately, Blobel was able to travel to West Germany (the Berlin Wall had not yet been built), and in 1954 he left his family's home to study medicine. After earning a medical degree at the University of Tübingen and completing two years of internships, Blobel ultimately decided that he was more fascinated by the unsolved problems of medicine than by practicing it. An older brother, Hans, a Fulbright Scholar at the University of Wisconsin-Madison, helped Blobel secure a graduate fellowship at the same school.
After earning his Ph.D., Blobel went to the Rockefeller University to work in the laboratory of cell biologist George Palade, who won the Nobel Prize in 1974 for discovering all the major structures of the cell and their functions. He was Blobel's most influential mentor. He taught me how to "conceptualize a collection of disparate facts, to formulate working hypotheses, and to design experiments to test these hypotheses," Blobel once recalled.
The WWII destruction of Dresden made a lasting impression on Blobel, and in 1994, he founded Friends of Dresden, Inc., an American charitable organization dedicated to raising funds to rebuild and restore this city's landmark buildings. The group is reconstructing Frauenkirche, a church that once dominated the city's skyline. After winning the Nobel Prize, he decided to donate the prize money—nearly $1 million—to the Friends of Dresden. "It is one of the great pleasures in my life to donate the Nobel Prize money, in memory of my sister Ruth, to the rebuilding of the Frauenkirche," Blobel noted.