Peter Walter

Peter Walter is a German-American molecular biologist and biochemist. He earned a B.S. degree in chemistry from the Free University of Berlin, an M.S. degree in organic chemistry from Vanderbilt University, and a Ph.D. in biochemistry from the Rockefeller University. He is currently Professor and Chairman of the Department of Biochemistry and Biophysics at the University of California, San Francisco (UCSF).

Peter Walter's laboratory at UCSF is engaged in studying protein folding and protein targeting, focusing on the signal recognition particle (which he identified and characterized some years ago as a graduate student with Günter Blobel at the Rockefeller). Peter Walter has discovered a feedback loop within cells called the unfolded protein response. Cells need the right amount of endoplasmic reticulum (ER) to properly fold new proteins. If there is too little ER, misfolded proteins accumulate, triggering a signaling pathway between the ER and the nucleus that produces more ER to increase the capacity with which the proteins can be properly folded. If this feedback loop does not work and misfolded proteins accumulate inside the ER, the cell commits suicide. Walter's lab has identified three genes centrally involved in the unfolded protein response. Peter Walter is an Investigator of the Howard Hughes Medical Institute and a member of the National Academy of Sciences.

Professor Walter is a co-author of Molecular Biology of the Cell, now in its fourth edition.