Profile of Peter Walter
- Tinsley H. Davis, Freelance Science Writer
As the machinery of the endoplasmic reticulum (ER) chugs away, the enzyme Ire1 keeps watch for clogs in the protein-folding pipeline. With one foot in the cytosol and the other inside the ER, Ire1 senses a build-up of unfolded proteins and activates a downstream signaling cascade that results in numerous responses, including the construction of more ER. Biochemist Peter Walter, elected to the National Academy of Sciences in 2004, has been investigating Ire1’s trigger of the cytosolic signaling cascade since his laboratory (and concomitantly that of Joe Sambrook’s at the University of Melbourne, Melbourne, Australia) discovered the enzyme in 1993 (1, 2). In concert with fellow Academy member and University of California, San Francisco, colleague Robert M. Stroud, Walter takes a look at the other side of Ire1. Walter’s and Stroud’s dual Inaugural Article (3), published in a previous issue of PNAS, describes the crystal structure and mechanism of how Ire1’s luminal domain senses unfolded proteins, suggesting a model that changes the current paradigm.
Germany to Tennessee
Walter, who currently chairs the Biochemistry and Biophysics Department at the University of California, San Francisco, was born in Berlin in 1954. “When I was 12, I was convinced that I wanted to become a scientist,” he says, “but I didn’t particularly enjoy biology then.” He recalls that it was a lot of cataloguing and memorization, not like the “science by inquiry that is taught now. Even chemistry was basically taught by watching,” he recalls. He owned a chemistry set that he liked to play with at home. “In retrospect, we played with things that I wouldn’t like my kids to play with. Society is much more safety-conscious these days,” he says. Walter fondly remembers his high school teacher Dr. Dietrich Warnatsch as “fantastic. He gave us a lot of freedom as students,” says Walter. …
